• 설비공학논문집
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• 제16권10호
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• pp.969-976
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• 2004

Building energy saving is one of the most important issues in these days. Energy saving control strategies should be developed properly to achieve the saving. One of such area we could apply is the HVAC (Heating, Ventilation and Air-Conditioning) system. Through the optimal control algorithm for building energy management system (EMS), you can not only save the cost of building energy, but also protect HVAC system components against the unexpected condition. In order to verify the effectiveness of building energy saving, field test was accomplished for several months at 'A' building. And to get the measured data, remote control was used. If the remote control is used in BAS (Building Automation System), control and monitoring can be done for all of the building systems, such as HVAC, power, lighting, security and fire-alarm etc. anywhere any time. Using the remote control, Control and monitoring is possible for the testing system without going there. As the results of field test, we could reduce $5{\sim}10\%$ of the building energy cost.

• International Journal of Computer Science & Network Security
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• 제22권1호
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• pp.21-26
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• 2022

This study touched on the effect of the different electronic course designs on the programming skills of university students. The researcher used the experimental research design of a quasi-experimental of two experimental groups to achieve the objectives of the study. The first group underwent an electronic course designed in the holistic pattern, and the second group was taught a course in a sequential pattern. This experimental design was intended to measure the impact of these two learning modes on the learners' cognitive and performance achievement of programming skills. An achievement test and observational form were the data collection tools. Data were analyzed statistically using Pearson correlation, Mann Whitney Test, and Alpha Cronbach. The findings revealed statistically- significant differences between the mean scores of the students of the first and second experimental groups in favor of the former concerning the observational form and the latter in the cognitive test. Based on the findings, some recommendations are suggested. Due to their effectiveness in the educational process, expanding using the e-courses at universities is vital. The university teachers are highly recommended to design e-courses and provide technical and material support to the e-courses user to fulfill their design purpose.

• International Journal of Computer Science & Network Security
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• 제21권11호
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• pp.59-66
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• 2021

Many incidents of Carbon Monoxide (CO) poisoning have occurred because of people being unaware of its presence. There are currently available systems on the market, but they are limited to measuring CO in a certain area and lack vital functions. Additionally, little to no evidence-based information on their quality was available. Thus, a mobile application for detecting CO gas leakage in a vehicle and critical features to assist victims was developed. A usability and functionality test were conducted to determine the product's quality utilizing nine usability and six functionality task scenarios (n=5). Then, a System Usability Scale test was performed to obtain system satisfaction, usability, and learnability (n=50). The usability and functionality test shows that all the tasks given for both tests were 100% successful. The overall score obtained for SUS was 71.4, which indicates good acceptance and usability. Around 20% of respondents claimed that they would need the support of a technical person to be able to use the application and that they needed to learn a lot of things before they could use the application, which indicates the overall high learnability of the application. The result provides empirical evidence that the CO gas leakage detection mobile application is successful and receives good usability, functionality, acceptability, learnability, and satisfaction assessments. DetGas could benefit automobile owners and other stakeholders by mitigating the risk and harm associated with gas leaking that exceeds the safe limit.

• Steel and Composite Structures
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• 제44권6호
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• pp.899-912
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• 2022

To study the seismic performance of the all-steel buckling-restrained brace (BRB) using the novel soft steel LY315 for core member, a total of three identical BRBs were designed and a series of experimental and numerical studies were conducted. First, monotonic and cyclic loading tests were carried out to obtain the mechanical properties of LY315 steel. In addition, the parameters of the Chaboche model were calibrated based on the test results and then verified using ABAQUS. Second, three BRB specimens were tested under cyclic loads to investigate the seismic performance. The failure modes of all the specimens were identified and discussed. The test results indicate that the BRBs exhibit excellent energy dissipation capacity, good ductility, and excellent low-cycle fatigue performance. Then, a finite element (FE) model was established and verified with the test results. Furthermore, a parametric study was performed to further investigate the effects of gap size, restraining ratio, slenderness ratio of the yielding segment, and material properties of the core member on the load capacity and energy dissipation capacity of BRBs.

• 융합보안논문지
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• 제8권3호
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• pp.19-24
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• 2008

침입차단 시스템, 침입탐지 시스템 등 정보보호제품이 얼마나 안전하게 개발되고 구현되었는지 검증하기 위한 방안으로 공통평가기준(CC)를 제정 하여 제품을 평가한다. 이에 기존까지 적용된 CC v2.3에서 버전이 3.1로 전환이 되며 가장 큰 차이점인 정보보호 제품에 대한 평가방법론을 사전 확보하여 버전 3.1 수용 준비가 요구되고 있다. 이에 본 연구에서는 CC v3기반 합성제품 시험 및 취약성 분석 방법에 대한 연구를 진행하였다. 특히 합성형 정보보호제품 시험방법론을 기존원칙과 세부 방법론으로 분류하여 구체적 방안을 제시하고자 한다.

• 한국인터넷방송통신학회논문지
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• 제13권3호
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• pp.177-181
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• 2013

최근 NFC(Near Field Communication) 기반의 통신 기능을 채용한 스마트기기 및 OS 등이 확산되면서, 기존의 RFID를 이용한 다양한 응용분야가 NFC로 대체되고 있다. Smart NFC 기술은 기존 서비스 및 기기와 쉽게 융 복합이 가능하며, 스마트폰을 활용한 결제 의료 인증 등 새로운 Network Communication 패러다임의 창출이 예상되고 있다. Smart NFC 보안 인증기기(Smart NFC Security Authenticator: SNSA)의 H/W와 S/W를 개발하고, 무선통신 시험 결과 허용기준값 이내를 만족하고, 토폴로지 영향의 실험 및 분석 결과, Daisy Chain 토폴로지가 Star 토폴로지에 비해 신호성능이 우수함을 보였다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.678-682
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• 2005

IETF suggested AAA for safe and reliable user authentication on various network and protocol caused by development in internet and increase in users. Diameter standard authentication system does not provide mutual authentication and non-repudiation. AAA authentication system using public key was suggested to supplement such Diameter authentication but application in mobile service control nodes is difficult due to overhead of communication and arithmetic. ID based AAA authentication system was suggested to overcome such weak point but it still has the weak point against collusion attack or forgery attack. In this thesis, new ID based AAA authentication system is suggested which is safe against collusion attack and forgery attack and reduces arithmetic quantity of mobile nodes with insufficient arithmetic and power performance. In this thesis, cryptological safety and arithmetical efficiency is tested to test the suggested system through comparison and assessment of current systems. Suggested system uses two random numbers to provide stability at authentication of mobile nodes. Also, in terms of power, it provides the advantage of seamless service by reducing authentication executing time by the performance of server through improving efficiency with reduced arithmetic at nodes.

• Journal of Electrical Engineering and Technology
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• 제10권4호
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• pp.1759-1764
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• 2015

Glow corona is a kind of streamer-free corona that can suppress upward leaders in transmission lines. Thus, it has good application potential in lightning protection. This paper investigates its corona characteristics. The suppression characteristic of glow corona on streamer is studied in air gap under negative DC voltage by wrapping thin wires on the electrode. The effect of thin wire winding patterns on the gap breakdown voltage is analyzed. Results are considered to be attributed to the inception condition of glow corona. Thus an inception test of glow corona is also conducted, and the inception voltage is obtained. Results show that the inception voltage decreases with short winding pitch. Thus an investigation on the inception of glow corona influenced by thin wire is conducted, and an influential factor is proposed to evaluate the influence. The inception regular of thin wire glow corona presented in this paper has certain reference value for the application of glow corona in transmission lines.

• 한국정보시스템학회지:정보시스템연구
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• 제14권2호
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• pp.1-23
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• 2005

Theoretically, both of fund transfer and balance inquiry which are typical Internet banking services are influenced by the beliefs on the use of Internet banking such as perceived risk and convenience, which have been shown as in the other studies. However, the use of fund transfer can be more sensitive than that of balance inquiry by the beliefs on Internet banking use since the former is not only more risk involved but also more complicated in using than the latter. The objective of this study is to analyze the relationship between the use of two Internet banking services-fund transfer and balance inquiry-and the beliefs on Internet banking use-security risk, convenience and social Influence. For this purpose, we provide the research model for explaining the difference between balance inquiry and fund transfer in the degree of influencing by security risk, convenience and social influence and test it empirically by collecting data from surveying for 206 internet banking users. In result, we show validity of the suggested model by Partial Least Square(PLS) approach.

• 한국정보통신학회논문지
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• 제10권3호
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• pp.437-445
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• 2006

보안 키 관리 기능은 망 보안을 위 한 필수 요소 중 하나로서, IPSec, HIP 등 다양한 프로토콜에서 이러한 기능을 요구하고 있다. 망 계층에서 보안 키 관리 기능을 제공하기 위한 두가지 방안이 있는데, 그것들은 디렉토리 서비스를 이용하는 것과 DNS 서비스를 이용하는 것이다. 본 논문은 디렉토리 서비스를 이용하여 보안 키 관리 시스템을 구현한 예를 소개한다. 디렉토리 서비스(OpenLDAP)와 공개키 알고리즘(FLINT/C), IPSec(FreeS/WAN)의 기능들을 공개 소프트웨어들을 이용하여 구축하였으며, 보안 키 관리 시스템을 이용한 암호화된 메시지 교환, IKE 데몬과의 연동을 통해 구현된 관리 시스템의 기능을 확인하였다.