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pISSN : 1975-7700 / eISSN : 2734-0570

2020 KCI Impact Factor : 0.42
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2018, Vol.13, No.1

  • 1.

    A Greenhouse Control System Based on Best-Fitted PID Controller to Minimize Energy Cost

    Vasanth Ragu | Myeongbae Lee | Cho Yong Yun and 2other persons | 2018, 13(1) | pp.1~9 | number of Cited : 0
    Abstract PDF
    In these days, many of greenhouse environments are based on electric devices and ICT technologies. The model suggested in the paper the detailed design of a greenhouse control system adaptability with PID (Proportional Integral and Derivative) controller. Compared with a previous greenhouse control system (GCS), the proposed system is focused on the detailed design of greenhouse control process to minimize energy costs for crop growth in a greenhouse. In the suggested system, there are two important processes namely, Greenhouse Control Process (GCP) and Crop Growth Process (CGP). The two process data, which are crop status information and climate set-point information, are stored in an information storage database. The PID controller works inside the GCP and the environment control decision works inside the CGP. According to the service decision algorithm of it, the controller will work properly in a greenhouse. Using the suggested system with the different combinations such as P, PI, PD and PID, a user can easily simulate energy costs for a greenhouse system and efficiently design the best optimized controller in the greenhouse system. Therefore, the suggested system can provide a feasible solution to reduce or minimize energy cost in the greenhouse and help developments of various applications related with greenhouse environments.
  • 2.

    Research on Factors Affecting Smartphone App Market Selection: App Market Platform Provider’s Perspective

    Ho Lee | Jae Sung Kim | KyungKyu Kim and 1other persons | 2018, 13(1) | pp.11~23 | number of Cited : 2
    Abstract PDF
    This paper empirically investigates the factors that influence the consumer choice of an app market based on the rational choice theory. The app market is the only channel where a consumer can buy smartphone apps, which give various functional convenience and are considered to be a major contributor to the proliferation of smartphones. Analyses of 281 questionnaires show that usability and structural guarantees as benefit factors significantly influence the app market choice. From the cost perspectives, both monetary and non-monetary conversion costs are found to significantly influence the app market choice. On the other hand, customer trust, information quality, and market image were found to have no significant effect on app market selection. In particular, Korean app market platform providers (KT, LG U +) seem to be superior in terms of structural guarantees, such as customer center operation and damage compensation regulations, compared to overseas app market platform operators (Google). However, in the case of the Google App Market, it is pre-installed on all Android phones, so it is not inconvenient to install additional apps to use other app market. This is disadvantageous to domestic app market platform operators, and it is necessary to establish a policy solution point. In terms of operator costs, both monetary and non-monetary conversion costs have a significant impact on app market choice. In particular, non-monetary conversion costs have a negative impact on Korean app market platform operators. It can be explained that the service expectation level of the domestic app market is low and it is recognized that the time cost factor such as membership is large for new users to use. It seems to be necessary to improve the domestic app market business. Meanwhile, extant research on smartphone apps focuses on the purchase of apps themselves, but not on the selection of the app market itself. In order to fill in this gap, this study focuses on the determinants of app market selection, including the characteristics of an app market and the switching costs.
  • 3.

    A Study on the Direction of Aircraft Maintenance Education Based on Job Interest Type and Aptitude

    Park heui-kwan | 2018, 13(1) | pp.25~36 | number of Cited : 0
    Abstract PDF
    Recently, the number of students who want to become aviation mechanics has been rapidly increasing, and many education institutions are training aviation mechanics. In the Ministry of Land, Transportation and although the institutional management of the educational operating system, Education has shown a lot of differences in institutional learning environment, curriculum, completion criteria. It is necessary to establish a positive educational system for students and airlines. For this purpose, this study analyzed the types and the aptitude of the students who want to become mechanics. Also, the effects of interest types and aptitudes on academic achievement were analyzed. Review the aviation maintenance sector jobs and their characteristics were navigate the competence areas required for the performance of duties based on it. The purpose of this study is to find out the direction of education that can enhance the job interest type and aptitude of students who want to become aviation mechanics. With areas to be strengthened when considering the job characteristics in the aviation mechanic training and education, such as numeracy, concentration, judgment, circumstances, coordination ability, in order to improve this, we have to run a training program such as Team-Project Class, Maintenance CRM, Field Experience Learning, and conclude that we should include the liberal arts course and the self-development comparison program
  • 4.

    Development of a Medical Software Test System based on IEC 62304, IEC 60601-1, ISO 14971

    A Young Park | Kiwon Song | Jeong-Hwan Park | 2018, 13(1) | pp.37~44 | number of Cited : 0
    Abstract PDF
    Medical devices are becoming increasingly intelligent with the development of the fourth industrial revolution. In case of defects in medical equipment and software, it is directly related to injury, so the testing process is very important. Therefore, Verification of new solution-level medical software (eg, personal care and preventive care through healthcare) is becoming important. In this paper, we developed a system for testing medical software. The system can manage tests based on international standards(IEC 62304, IEC 60601-1, ISO 14971), and check defect rates. In addition, the proposed system provides results in the form of reports so that test data can be accumulated and compared, analyze. Then, We have tested the Electronic Medical Record to verify the system. The system proposed in this paper can increase the satisfaction of the ease of use of the system through the quantitative data input and the reliability of the result value. Future research will require improvements to the system to be able to support Class B and Class C. By accumulating test data, We need to optimize for each medical device based on the frequency of exposure of risks.
  • 5.

    A Study on the Factors Analysis to Loyalty of the Press Website Users

    Jaehyeon An | 2018, 13(1) | pp.45~53 | number of Cited : 0
    Abstract PDF
    The management crisis of the media is transforming the way in which traditional media control strategies differ. There have been newspaper clippings of printing press and switching to web pages to reduce printing costs, and greatly reduced the number of investigative staff needed to produce print newspapers and reorganize the web news for web news content. There is also speculation that profits from the traditional news media will not fall short of the revenue growth of the Internet. Recently, it has emerged as a critical topic in the media's survival strategy for how to design an internet news media strategy. Newspaper readers do not read news from paper newspapers and use various media such as web and mobile to consume news. As newspapers consume content through various platforms, the media market has become the exclusive market for several media companies. As the paper's readership falls flat, newspapers appeal to readers through various channels to overcome the limitations of paper media. Newspapers, which have remained unilaterally aware of the way they communicate independently of their readers, are now searching for images of their readers as flexible companies that provide customized contents and provide customized contents to readers. Efforts are being made to secure revenue by securing loyal customers and utilizing Internet media. Efforts to secure loyal readers will not be alone yesterday. Securing the reader's loyalty to the press website is an urgent task that must be addressed urgently. It is analyzed what components of the website's can stay on site longer and also lead to revisit. It is suggested how the organization's website and how the media outlets should be activated. The results of this study show that the content fidelity is very important to the user's loyalty to the user's loyalty and return time. It is needed to control the contents of the media website and use the website of the media website to enhance the relevance of the media website, and to organize the website specifically for the media website.
  • 6.

    Users' Neglect on Requests from Software Updating Messages : From the Construal Level Theory Perspective

    Sangcheol Park | 2018, 13(1) | pp.55~67 | number of Cited : 0
    Abstract PDF
    In updating softwares in PC usage surroundings, users generally tend to neglect updating messages. Based upon such a view, this study attempts to investigate how users neglect the updating messages from the software. By employing construal level theory (CLT), this study has investigated how users' neglect are differ by depending on the construal level as an individual disposition as well as both time distance and types of messages as situational conditions. 160 participants were presented with one of different scenarios by applying the experimental design of 2(construal level: high vs. low) × 2(temporal distance : near future vs. distant future) × 2 (updating message types : how vs. why) on users' intention to neglect the message. Results shows that the main effects of construal level, time distance, and types of messages on the intention to neglect are significant. Furthermore, the interaction effects including both two-way and three-way interaction among CLT variables are also significant. This study has a salient theoretical contribution to introduce new theoretical lens to explain IT user behavior. From the practical standpoints, it could also give IT service providers how they design message-contents for persuading end-users to accept the updating messages.
  • 7.

    Development of Smartphone Mobile Apps for Hearing Aid Using Sound Frequency Translation

    Jae Ho Kim | 2018, 13(1) | pp.69~76 | number of Cited : 0
    Abstract PDF
    As the global population is aging, the use of hearing aids is expanding, and the demand for technologically advanced digital hearing aids is steadily increasing compared to conventional analog hearing aids, and major manufacturers are increasingly adopting digital hearing aids it is focusing. As the capacity of smartphone batteries improves, the duration of hearing aid apps is also increasing. In addition, since wireless handsets are linked to smartphones, smartphones have a sufficient environment to implement hearing aid apps. Therefore, if a smartphone is used to implement the function of a hearing aid, it is possible to construct a high quality hearing aid even at a low construction cost. The strength of implementing a hearing aid app on a smart phone is that it can implement intelligent hearing aids by implementing various types of algorithms. For example, you can implement a variety of additional features such as noise reduction, high frequency conversion, acoustic pattern recognition, intelligent volume control, feedback cancellation, and speech enhancement. Since there is no additional hardware cost to implement these functions, it is possible to implement intelligent hearing aids at low cost, and it is believed that hearing aids can be supplied to more hearing impaired people. In this trend, we want to develop smart phone apps that are cheaper and more versatile than standalone hearing aids by utilizing the sound processing function of smartphones.
  • 8.

    EEG Variation Analysis on Difference of Autostereoscopic 3D Image Quality

    Choi Yoo Joo | 서정근 | 2018, 13(1) | pp.77~86 | number of Cited : 0
    Abstract PDF
    Various studies have been conducted to assess the effects of 3D contents with glasses using electroencephalogram (EEG), but there is a limited research for 3D contents using autostereoscopic display. In this study, we focused to study for sub-b wave frequencies, covering, SMR, M-beta, and H-beta frequencies and various indices of the EEG was used to evaluate stress, attention, relaxation, and vigilance upon quality variation of autostereoscopic 3D images. There were statistical significance for M-beta and H-beta powers when watching for low-quality 3D images were higher than those for high-quality. For various EEG indices, stress and attention indices show statistically significant differences between low and high resolution of 3D images. Stress and attention indices were increased when watching for low-quality 3D images. These results suggest that subjects viewing low-quality 3D contents through lenticular lens experience more discomfort or fatigue than those for high-quality, which resulting from the greater M-beta and H-beta powers for those watching low-quality 3D contents. In conclusion, these results confirm that EEG analysis can be used as a tool for evaluating visual fatigue or stress when watching autostereoscopic display with lenticular lens type.
  • 9.

    Structural Similarity Evaluation between Proteins Based on 3D Model Shape Analysis

    Sung Hwan Chun | Choi Yoo Joo | 서정근 | 2018, 13(1) | pp.87~103 | number of Cited : 0
    Abstract PDF
    Over 130,000 protein structures are solved and deposited in the PDB with molecular structural models of high resolution determined by X-ray diffraction or NMR studies. Those conventional methods for structural determination and similarity comparison are not applicable for therapeutic proteins due to their own technical limitations. However, assessing structural comparability for therapeutic proteins is critical during biopharmaceutical development or manufacturing processes. Currently, those assessments were done by various spectroscopic methods but those methods are not giving specific structural information. Moreover, recent developments such as single angle X-ray scattering (SAXS) techniques can provide low-resolution structural models for proteins more easily than those for X-ray diffraction or NMR studies. These enable us to develop fast and reliable method for the similarity assessment of low-resolution surface models of therapeutic proteins using geometric shape descriptor. Our descriptor consists of two features, local and global. The local feature calculates the distance distribution for each vertex from the center in 510 bins. For global feature, the ratio, x to y axis and x to z axis from the surface model of proteins were determined. A geometric shape descriptor is then constructed by combining local and global features with weights. We applied this geometric shape descriptor to assess structural similarity for the therapeutic protein, insulin models. Our geometric shape descriptor can clearly classify human insulin models and insulin analog models which having locally different structures. The performance of the geometric shape descriptor was evaluated by comparing to the conventional method of the root mean square deviation measure (RMSD) which computes the minimum average distance between the backbones of superimposed. The result shows that the performance of the global shape descriptor is comparable to that of RMSD. This provides potential applications to classify protein structure and compare low-resolution protein structures for EM and SAXS.
  • 10.

    Development of Education Curriculum for Aviation-IT Convergence Security Manpower Training

    김성종 | 2018, 13(1) | pp.105~110 | number of Cited : 0
    Abstract PDF
    Innovation through convergence, compositeness, and characterization in college education is highly required in the era of the Fourth Industrial Revolution, since current education systems rarely cultivate talented men with creativity and enthusiastic thinking. Therefore, new paradigm in future education systems is needed, which are represented as hyperconnectivity and superintelligence. This paper developed and introduces a competency based curriculum development model for training security forces in Aviation-IT. The specific curriculum development process is composed of the stages of analysis, designing, development, implementation, and evaluation. Specific courses developed according to the development model of the curriculum have a step-by-step curriculum system. The curriculum possesses an educational system of on-the-job training including an education stage of security infrastructure with the technology of Aviation-IT, a professional skill acquisition stage, and a mentor program. Among the proposed education levels, level 1 is applied in the lower grades, level 2-3 is applied in the upper grades, but can be flexibly applied depending on the number of credits needed per school, and the number of credits required. The proposed curriculum development model is expected to be available in various applications from other similar fields, and the development of multiple curriculum. Further research tasks include analyzing education outcomes and establishing a feedback system through surveys by students, professors and field managers.
  • 11.

    A Study on Ultra Multi-channel Audio Coding for Realistic Audio Services

    Kwangki Kim | 2018, 13(1) | pp.111~120 | number of Cited : 1
    Abstract PDF
    Realistic audio services based on ultra multi-channel audio signals are indispensable for realistic high quality video such as 3D movies and UHD broadcasting. Generally, since the ultra multi-channel audio signals to be more than 10.2 channels has very high data rate, an efficient ultra multi-channel audio coding method is required to enable the realistic audio services in a wired/wireless network or communication environment. In this paper, we propose the ultra multi-channel audio coding based on space division of more than 10.2 channels playback layout for efficiently handling the ultra multi-channel audio signals with low bit rate and complexity. The proposed method is originated by considering the conventional 5.1 channel playback system and the usage of the multi-channel audio coder such as MPEG Surround or SSLCC. Input ultra multi-channel audio signals are divided into five spaces such as Center, Left Front, Left Back, Right Front, and Right Back and allocated signals to each space are independently encoded. One down-mix and power ratio parameters for each space are extracted through the encoding process and five down-mix signals from each space are coded by the conventional multi-channel audio coding. We implemented a simple ultra multi-channel audio coder adopting the down-mixing and the power ratio of the audio signal to check the feasibility of the proposed method and we confirmed that the proposed ultra multi-channel audio coding has low bit-rate to be less than 200 kbps for 10.2 channel audio signals. Since the proposed method focused on low bit-rate and complexity and it may be suffered from the degradation of sound quality, researches on the improvement of sound quality using a variable subband and a residual signal processing remain as future works.
  • 12.

    Reliability Analysis of Systems Using Level (λ, 1) Interval-valued Fuzzy Sets Considering the Widths

    Cho, Sang Yeop | 2018, 13(1) | pp.121~127 | number of Cited : 3
    Abstract PDF
    In the fuzzy set theory there are various types of the fuzzy sets to deal with the reliability of systems. In the fuzzy sets the degree of membership is represented by real number. ∈ . Sometimes the membership degree of the fuzzy sets can not be represented by real number because the degree of membership itself may has the uncertainty. To overcome this problem the interval valued fuzzy sets are proposed. In the interval valued fuzzy sets the degree of membership is represented by interval [, ]. is the smallest degree of memebership and is the greatest degree of membership. [, ] ⊆ . 0 ≤ ≤ ≤ 1. Once the degrees of membership of the interval valued fuzzy serts are assigned as some reals and then these numbers can not be resized. In order to resolve the this demerit the level (λ, 1) interval valued fuzzy sets are introduced. In the level (λ, 1) interval valued fuzzy sets the smallest degree of membership can be resize using the λ. In this paper we propose the way to evaluate the reliability of systems based on the level (λ, 1) interval valued fuzzy sets and its widths. The proposed method may be used to analyze the reliability of systems which have the concept of the level (λ, 1) interval valued fuzzy sets and may be able to evaluate the relaibility more accuracy than the interval valued fuzzy sets because of using the the level (λ, 1) interval valued fuzzy sets and its widths.
  • 13.

    Comparison of System Resource Usage for Screen Image Transmission

    Kwon Oh-Sung | 2018, 13(1) | pp.129~137 | number of Cited : 0
    Abstract PDF
    In General, the Screen Control Programs contains the functions that is able to capture PC screen and send the images to a predefined server. The applications, for examples, are PC remote controller, remote login, video conferencing and PC screen recording programs. These application have to run with background process style at PC. Also, the programs need to executed with minimum CPU time and small memory requirement. The programs must not disturb PC users' ordinary activities and generate time delay of mouse or keyboard input. For the effectiveness and efficiency of our proposed program, We perform several experimentals to find the best algorithm and implementaion method. We are preferentially designed image generation and transmission modules each. Our program is implemented with the two modules. We do experimental work in the two ways. The one method is unified manner combined with image generation and transmission. The other one is seperation manner of the two modules. In this paper, We measure the CPU time and the consumption of memory working set to each method. In the experimentals, the unified method is 8.09 % higher than the seperation method in CPU time. In the memory usage, the seperation method is higher 20.9 % than the unified method. On the other hand, the combined method shows sometimes peak increasement of CPU time. We proposed a dynamic and selective approach of the execution style based on the PC resource environment.
  • 14.

    Performance Evaluation of the Error Recovery based Object Relation in SCTP

    CHOI WON KEUN | 2018, 13(1) | pp.139~146 | number of Cited : 0
    Abstract PDF
    The main issue of designing multimedia services is the support and integration of a wide variety of applications. QoS(Quality of Service) provides a unifying theme on which the facilities and functions of the system standards can be constructed. In distributed system, QoS guarantees are fundamentally concerned with the end-to-end communication between applications. The reliability of the transmission is one of the important QoS parameters. Including SCTP(Stream Control Transport Protocol), conventional error detection and recovery methods, however, do not consider the integrated viewpoint of multimedia object data. In the first reference paper, we have designed and proposed the multimedia-oriented error control method based on multimedia object information called EROR(Error Recovery based Object Relation). In this paper, we have investigated its performance evaluation by transmission delay. The results show that the EROR method manifests superior performance as the error occurs more frequently. When the frame transmission succeeds, it can be found that the EROR method reveals shorter average frame delay than SRER(Selective Repeat Error Recovery). On the other hand, the performance evaluation on the both methods show closer results as the error rate decreases. In the case of the extremely low error rate, furthermore, the both methods show the almost same performance results. Therefore, it makes SCTP have the high performance and flexibility. It should have the reducing effect of the network resources as well as satisfy the user’s requirements.
  • 15.

    Compensation for Consumer Damage and Dispute Resolution Caused by Personal Data Leakage - Focusing on Compensation for Emotional Distress -

    LEE JONG SIK | 2018, 13(1) | pp.147~160 | number of Cited : 0
    Abstract PDF
    All cases of compensation and dispute resolution involve some form of emotional difficulty. Even when material compensation is made, it is hard to say that it makes up for non-pecuniary losses, that is, emotional distress. Then is it currently possible to be compensated for emotional distress in all legal disputes? Although possible in some cases, it is not easy to claim damages for emotional distress since the action of the defendant has to be shocking and extreme, and concrete enough to prove that the defendant’s deliberate and reckless action caused emotional distress. There must also be factual evidence such as receiving medical treatment as a result of the defendant’s action, as well as a causal relationship between the defendant’s action and the consumer’s damage. Therefore, it is difficult to claim damages for emotional distress, and only a few cases which satisfy all the above conditions have received compensation. The current Consumer Protection Law stipulates 1) the right to safety 2) the right to be informed 3) the right to choose 4) the right to be heard 5) the right to redress 6) the right to consumer education 7) the right to organize 8) the right to a healthy environment as the basic rights of consumers. This paper focuses on compensation for emotional distress included in 5) the right to redress, and more specifically, the compensation for consumer damage following the leakage of personal information on the Internet. Material compensation is important, but to make a better policy for both consumers and companies, it is also important to analyze the situation in which the victims suffer from emotional distress that takes place in various situations following personal data leakage, and ensure that those victims are provided with better and real compensation.
  • 16.

    Comparison of Energy and Power Characteristics According to the Types of Solar Panels and Batteries

    Kwon Oh-Sung | 2018, 13(1) | pp.161~168 | number of Cited : 2
    Abstract PDF
    At environment not connected to the power-grid for electronic devices, the general solution is solar energy system. Solar energy systems consistes of the three components solar panels, battery charger and solar batteries. In this paper, we analysis the relation of the three components and the total power amount and characteristics of our soloar system. We implement a solar energy generation system with 250 Watt solar panels and analysis the obtained data from our solar system during 39 days. The experimantal items are the placement direction of solar panels, the duration of sunshine, and the power change according to seasonal variation. We measure the characteristics of chemical and lithium-ion batteries for solar power charging and the solar power capability of our implemented system. We experiment the change of panel direction with a predefined angle degree 30. We can not obtain meaningful different values of power amount between the South and South-West direction, but rather can get similar values of the two direction testing according to the short experimental period. To measure the duration of sunshine, we measure 1.50 V and 12.0 V entry time each. we can confirm the entry time correspond to the sunrise and sunset time of the days. In case of lithium-ion batteries, the entry process is more smooth than the chemical betteries. In our experimentals, the chemical batteries has seen a rapid increase in the 12.0V entry graph. The both batteries has shown a stable power generation in the middle of day with sufficient sunshine amount. Our experimental result demonstrate that the chemical batteries has 0.28V power variation, the chemical batteries has 0,05V power variation respectively. We confirm that we can construct the efficient solar power generation system according to the our experimentals of the panel direction, the characteristics of batteries.
  • 17.

    Improving Predictive Accuracy of User-based Collaborative Filtering Using Word2Vec

    Kang, BooSik | 2018, 13(1) | pp.169~176 | number of Cited : 5
    Abstract PDF
    Word2Vec is a most popular method in text mining area, recently. It converts words to vectors using association among words in sentences. Similar words are nearly located in the vector space. Improving predictive accuracy of recommender algorithms is a major work in the area of recommender systems. User-based collaborative filtering recommends products using the information about product preference of Neighbors. This study proposed a method to compute user similarity using vectors of users by Word2Vec instead of using traditional method. In order to use Word2Vec, we separate sentences first, and then find corpus that is meaningful word set of the sentences. For using Word2Vec in user-based movie recommender, we find users that have seen same movies first, we substitute an user to a word and user list of a movie to corpus of one sentence. There can be several methods to compose the sentences in recommender systems. This study considers two methods, first method constructs a sentence per movie and second method can construct several sentences per movie. After sentence construction, it enters corpus of sentences into Word2Vec and computes vectors of users, and then computes user similarity by coefficient corelation method using the vectors of users. Using the similarity, it recommends products by user-based collaborative filtering. To validate, the proposed methods were applied to filmtrust dataset. The experimental results of repeating 10-fold cross validation three times showed that mean MAE of user-based collaborative filtering(wvCF3.0) applying Word2Vec improved the predictive accuracy greatly than that of conventional collaborative filtering method(uCF). Also, it showed that the sentence expansion method(wvCFthree) constructing several sentences per movie is better than the one sentence method(wvCF3.0) constructing one sentence per movie for improving the predictive accuracy. To test statistical significance between uCF and wvCF3.0, and between wvCF3.0 and wvCFthree, we experimented paired t-test and confirmed the statistical significance.
  • 18.

    The Design and Performance Analysis of Fed Inset Patch Antenna for ISM Band

    Choi, Jae Yeon | 2018, 13(1) | pp.177~185 | number of Cited : 0
    Abstract PDF
    This study presents the design theory of the patch antenna of the fed inset patch method and proposes a configuration of the fed inset patch antenna which have a unidirectional radiation pattern with a bandwidth of 1% - 5% designed at the frequency of 2.42GHz and a gain of 6dBi. There are several ways to feed the patch antenna, and the fed inset patch antenna is fed through a microstrip feed line connected to a particular point in the patch. The measured input impedance can be controlled by changing the position at which the microstrip is connected to the patch antenna. The reflection coefficient above was matched with a 50Ω microstrip line. A patch antenna with linearly polarized insertion feed is constructed and its performance is analyzed through suitable simulation and the analyzed results. The inserted microstrip patch antenna was designed and simulated at a resonant frequency of 2.42 GHz. The input return loss was -21.05 dB and the gain was 4.68 dB. The proposed design has a simple antenna structure and can be easily configured at low cost. The simulation results show that the antenna can be regarded as a candidate for various applications in the ISM band because of its good electrical performance.