• Journal of Industrial Convergence
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• v.20 no.7
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• pp.65-71
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• 2022

With the development of ICT, as the era of the 4th industrial revolution arrives, the amount of data is enormous, and as big data technologies emerge, technologies for processing, storing, and processing data are becoming important. In this paper, we propose a system that detects events through monitoring and judges them using hash values because the damage to important files in case of leakage in industries and public places is serious nationally and property. As a research method, an optional event method is used to compare the hash value registered in advance after performing the encryption operation in the event of a file leakage, and then determine whether it is an important file. Monitoring of specific events minimizes system load, analyzes the signature, and determines it to improve accuracy. Confidentiality is improved by comparing and determining hash values pre-registered in the database. For future research, research on security solutions to prevent file leakage through networks and various paths is needed.

• IEMEK Journal of Embedded Systems and Applications
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• v.18 no.4
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• pp.159-164
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• 2023

Solar energy harvesting IoT devices prioritize maximizing the utilization of collected energy due to the periodic recharging nature of solar energy, rather than minimizing energy consumption. Meanwhile, research on edge AI, which performs machine learning near the data source instead of the cloud, is actively conducted for reasons such as data confidentiality and privacy, response time, and cost. One such research area involves performing various audio AI applications using audio data collected from multiple IoT devices in an IoT edge computing environment. However, in most studies, IoT devices only perform sensing data transmission to the edge server, and all processes, including data preprocessing, are performed on the edge server. In this case, it not only leads to overload issues on the edge server but also causes network congestion by transmitting unnecessary data for learning. On the other way, if data preprocessing is delegated to each IoT device to address this issue, it leads to another problem of increased blackout time due to energy shortages in the devices. In this paper, we aim to alleviate the problem of increased blackout time in devices while mitigating issues in server-centric edge AI environments by determining where the data preprocessed based on the energy state of each IoT device. In the proposed method, IoT devices only perform the preprocessing process, which includes sound discrimination and noise removal, and transmit to the server if there is more energy available than the energy threshold required for the basic operation of the device.

• Journal of electromagnetic engineering and science
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• v.16 no.3
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• pp.169-181
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• 2016

This work presents a new method for enhancing the performance of a dual band Planer Inverted-F Antenna (PIFA) and its lumped equivalent circuit formulation. The performance of a PIFA in terms of return loss, bandwidth, gain, and efficiency is improved with the addition of the proposed open stub in the radiating element of the PIFA without disturbing the operating resonance frequencies of the antenna. In specific cases, various simulated and fabricated PIFA models illustrate that the return loss, bandwidth, gain, and efficiency values of antennas with longer optimum open stub lengths can be enhanced up to 4.6 dB, 17%, 1.8 dBi, and 12.4% respectively, when compared with models that do not have open stubs. The proposed open stub is small and does not interfere with the surrounding active modules; therefore, this method is extremely attractive from a practical implementation point of view. The second presented work is a simple procedure for the development of a lumped equivalent circuit model of a dual band PIFA using the rational approximation of its frequency domain response. In this method, the PIFA's measured frequency response is approximated to a rational function using a vector fitting technique and then electrical circuit parameters are extracted from it. The measured results show good agreement with the electrical circuit results. A correlation study between circuit elements and physical open stub lengths in various antenna models is also discussed in detail; this information could be useful for the enhancement of the performance of a PIFA as well as for its systematic design. The computed radiated power obtained using the electrical model is in agreement with the radiated power results obtained through the full wave electromagnetic simulations of the antenna models. The presented approach offers the advantage of saving computation time for full wave EM simulations. In addition, the electrical circuit depicting almost perfect characteristics for return loss and radiated power can be shared with antenna users without sharing the actual antenna structure in cases involving confidentiality limitations.

• Journal of the Korean Data and Information Science Society
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• v.22 no.4
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• pp.785-794
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• 2011

The population of internet users are rapidly increasing and the interest of the internet survey is also increasing. Recent years has seen a transition from traditional modes of data collection into internet survey. Some surveys are administered with mixed modes of traditional data collection methods and internet survey, and some surveys are conducted through internet only instead of traditional modes, such as telephone survey, postal survey, face-to-face interviews and so on. However, one of most crucial parts of a survey is the reliability of the collected data and internet survey is no exemption. Changwon National University has been annually conducting a survey of new students and transfer students with almost same contents of questionnaire. The survey is a longitudinal survey and it had been administered by paper-pencil surveys until 2009. In 2010 the survey was administered through internet. Every students has to login with student ID number and the last 7-digit of national identity registration number, and complete the 2010 survey before registration their courses. If they leave any question without being answered, then could not move to the registration site for courses. This study explores the distortion of responses using the new students survey of Changwon National University, which could occur when the survey responses are not confidential. We find that the distortion of responses occurs from the questions with social desirability pressure, pressure of winning favor with the researcher, and pressure of explaining their situations. There are no distortion of responses from the questions which are describing simple opinions or simple facts, for example, the place they plan to live while in school.

• Journal of the Korean Dietetic Association
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• v.3 no.2
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• pp.141-158
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• 1997

The purpose of this study were to investigate the job analysis questionnaire was mailed to 250 dietitians who are members of The Korean dietetic association practice group in self-operated foodservices(hereafter group A)and 250 dietitians who are employed in contracted foodservice companies(hereafter group B). Completed questionnaires were received from 285 dietitians(121 in self-operated, 164 in contracted) ; a response rate of 57%. Statistical data analysis was completed using the SAS/win packages for descriptive analysis, t-test, $x^2$-test, The results of this study can be summarized as follows. 1. The dietetic training or internship experiences were significantly different between the two sample group(p<.001), but the perceptions of needs for training or internship were not different between and they thought one to six month training would be needed for the job. 2. The question about the time needed in order to perform an expert job was answered significantly differently(p<.001) 3. Group A usually took part in obligatory continuing education and short-term training courses, and group B usually took part in obligatory continuing education and on-the-job trainings, respectively. However both group perceived all three types of educations would be needed for performing the job better. 4. As for the physical demands of the job, a certain degree of accuracy and dexterity for physical tasks and equipment operations was needed for the job. Concerning the mental demands, they answered that their job needs considerable creativity and judgement for planning and performing their tasks was needed. 5. As for responsibilities, group B's responsibilities were heavier than group A’s(p<.001) and need for confidentiality was also greater for group B than for group A(p<.001). 6. As for the supervising role differences, group A rarely received supervision from others and they were given directions only in essential situations, whereas group B was usually supervised when planning and performing their job and tasks, showing significant difference in positions between the two sample groups(p<.001). But each group supervised co-workers and employees in their department. 7. With regard to personal contact, both groups frequently contacted people in their department and other departments at the company and sometimes people outside the company. 8. Concerning the work environment, there were some risks and discomforts in the physical environment and there was no significant difference between the two sample groups.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.4
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• pp.19-26
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• 2018

In recent years, the substantial increase in the population's average age leads to an exceeded number of older persons comparing with the number of any other age group. As a result, both industry and academia are focused on the development of several solutions aimed to guarantee a healthy and safe lifestyle to the elderly. Ambient Assisted Living (AAL) approach is the way to guarantee better life conditions for the aged and for monitoring their health conditions by the development of innovative technologies and services. AAL technologies can also provide more safety for the elderly, offering emergency response mechanisms, fall detection solutions, and video surveillance systems. Unfortunately, due to the sensitive nature of AAL data, AAL systems should satisfy security requirements such as integrity, confidentiality, availability, anonymity, and others. In this paper, we propose an adaptive authentication protocol for the AAL systems. The proposed authentication protocol not only supports several important security requirements needed by the AAL systems, but can also withstand various types of attacks. In addition, the security analysis results show that the proposed authentication protocol is more efficient and secure than the existing authentication protocols.

• The KIPS Transactions:PartC
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• v.12C no.2 s.98
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• pp.301-308
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• 2005

According to banking online transaction grows very rapidly, guarantee validity about business transaction has more meaning. To offer guarantee validity about banking online transaction efficiently, certificate status verification system is required that can an ieai-time offer identity certification, data integrity, guarantee confidentiality, non-repudiation. Existing real-time certificate status verification system is structural concentration problem generated that one node handling all transactions. And every time status verification is requested, network overload and communication bottleneck are occurred because ail useless informations are transmitted. it does not fit to banking transaction which make much account of real response time because of these problem. To improve problem by unnecessary information and structural concentration when existing real-time certificate status protocol requested , this paper handle status verification that break up inspection server by domain. This paper propose the method of real~time certificate status verification that solves network overload and communication bottleneck by requesting certification using really necessary Reduction information to certification status verification. And we confirm speed of certificate status verification $15\%$ faster than existing OCSP(Online Certificate Status Protocol) method by test.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.175-181
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• 2019

In the case of a conventional single stage decompression regulator used for large depressurization in the hydrogen fuel cell system of a fuel cell electric vehicle (FCEV), problems can arise, such as pulsation, slow response, hydrogen brittleness, leakage, high weight, and high cost due to high decompression. Most of these problems can be overcome easily using two decompression mechanisms (two-stage structures). In addition, a wide outlet-pressure control range can be secured if an electronic solenoid is applied to the second decompression. Accordingly, it is necessary to improve the precision of the outlet pressure of a two-stage pressure-reducing regulator and develop techniques, such as leakage prevention, durability, light weight, and price reduction. Therefore, to improve the outlet pressure accuracy and prevent leakage, the structural part before and after decompression to improve the air tightness were divided and the analysis was carried out assuming that the valve part was closed (open ratio: 0%) after each initial internal pressure application.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.5
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• pp.163-175
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• 2017

The purpose of this study is to find out how to improve the brand image and loyalty of cafe by recognizing that social culture of middle school cafe, which is an important service quality in cafe establishment, emerges as a main characteristic of new coffee business. First, reliability, confidentness, professionalism, accessibility, and socio - culturality of the service quality of coffee specialty shops improve brand image. Confidence and professionalism play an important role in enhancing brand loyalty, and brand image has a significant effect on brand loyalty. Respectively, Among the service quality, social culture has a strong influence on brand image but it is not a direct influence on brand loyalty. Second, in the relationship between brand loyalty of coffee service quality, brand image shows full mediation effect on reliability, partial mediation effect on confidence, professionalism, accessibility, socialcultural property, and mediation effect on response and empathy. Third, as a result of analyzing the moderating effects of coffee shop types on the relationship between service quality and brand image of coffee specialty shops, reliability, confidentiality, and accessibility are positive factors in the nationwide franchise. On the other hand, in the private $caf{\acute{e}}$, professionalism and socio-culturality are the main factors for improving the brand image. In the case of the local franchise, similar to the franchise in the country, the improvement of service quality for responsiveness and professionalism is a positive factor Respectively. As a result, nationwide franchise $caf{\acute{e}}s$ have priority in enhancing brand image and brand loyalty through accessibility and assurance of service quality. On the other hand, in case of local franchise $caf{\acute{e}}$, it can be seen that the service quality is enhanced and the brand image and brand loyalty can be further improved through service professionalism and accessibility. On the other hand, regional cafes are more important than national franchises or local franchise cafes, and a strategy to enhance customer loyalty is needed through service strategies emphasizing socio - cultural aspects.