• 국제초고층학회논문집
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• 제11권4호
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• pp.363-368
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• 2022

For taller buildings with unconventional architecture, refined structural systems or in geographical areas with high wind conditions, performance-based design can be seen as an enhanced design process and is either a supplement to, or alternative to a prescriptive code-based design. The ultimate goal of Performance-Based Wind Design (PBWD) is to result in a building that better addresses key goals of performance over the buildings full life cycle. Major innovations around the use of a PBWD approach include nonlinear dynamic analysis for wind design, limited inelasticity in the main wind force resisting system elements, and system-based performance criteria. This paper discusses potential considerations and benefits made when using a performance-based approach, in addition to the general practicality of use, for the structural design on a few key tall buildings.

• Journal of Information Technology Applications and Management
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• 제30권6호
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• pp.17-29
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• 2023

In this paper, we aim to propose cyber security considerations and countermeasures for infrastructure and services in the UAM(Urban Air Mobility) Air Traffic Management field, which is one of the key elements of the UAM market that has not yet bloomed. Air traffic management is an important factor for safe navigation and social acceptance of UAM. In order to realize air traffic management, infrastructure and services based on solid network connectivity must be established. And for industries where connectivity is the core component, it can become an infiltration route for cyber threats. Therefore, cyber security is essential for the infrastructure and services. In detail, we will look into the definition of the existing air traffic management field and the cyber threats. In addition, we intend to identify cyber security threat scenarios that may occur in the newly designed UAM air traffic management infrastructure. Moreover, in order to study the cyber security countermeasures of the UAM air traffic management infrastructure, there will be analysis of the UAM operation concept. As a result, countermeasures applicable to the infrastructure and service fields will be suggested by referring to the cyber security frameworks.

• Journal of Electrical Engineering and Technology
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• 제12권3호
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• pp.1156-1165
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• 2017

A high performance interleaved bridgeless boost power factor correction (PFC) rectifier operating under the critical current conduction mode (CrM) is proposed in this paper to improve the efficiency and system performance of various applications, such as nano-grid systems. By combining the interleaved technique with the bridgeless topology, the circuit contains two independent branches without rectifier diodes. The branches operate in interleaved mode for each respective half-line period. Moreover, when operating in CrM, all the power switches take on soft-switching, thereby reducing switching losses and raising system efficiency. In addition, the input current flows through a minimum amount of power devices. By employing a commercial PFC controller, an effective control scheme is used for the proposed circuit. The operating principle of the proposed circuit is presented, and the design considerations are also demonstrated. Simulations and experiments have been carried out to evaluate theoretical analysis and feasibility of the proposed circuit.

• 한국융합학회논문지
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• 제13권5호
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• pp.551-558
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• 2022

본 연구는 65세 이상 노인 중 일반인과 당뇨병 진단을 받은 자를 대상으로 그룹 인터뷰를 통해 구강건강과 구강보건교육 시 고려사항을 파악하고자 위함이다. 연구 대상자는 G시 노인종합복지관을 방문하는 65세 이상 건강인 5명과 당뇨병 환자 5명을 2그룹으로 나누어 각 그룹 당 60-70분의 인터뷰를 진행하였다. 연구결과 핵심 주제는 '당뇨병과 구강질환과의 연관성에 관한 지식', '구강건강상태', '구강건강관리 방법', '구강보건교육 시 고려사항' 4가지의 주제모음이 도출되었다. 본 연구에 참여한 건강인들은 구강보건교육이 필요하다고 생각하는 내용이 치주관리방법, 임플란트, 전체적 구강관리, 전신건강이라고 대답하였고, 당뇨병 환자들은 당뇨병, 치주관리방법, 구강관리실천의 중요성이라고 대답하였다. 본 연구결과를 토대로 추후, 당뇨병 노인환자을 대상으로 맞춤형 구강보건교육 프로그램 개발이 필요할 것으로 사료된다.

• 한국과학교육학회지
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• 제29권2호
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• pp.253-266
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• 2009

This study was focused on analyzing students' informal reasoning patterns and their considerations in decision-making on socioscientific issues. This study involved 20 undergraduate students (10 biology majors and 10 non-biology majors) and showed how the two groups responded on socioscientific issues. Semi-structured interviews were conducted twice respectively based on six scenarios of gene therapy and human cloning. The result showed 93% of the total number of participants' decisions were made by rationalistic reasoning, whereas emotional reasoning was 49%, and intuitive reasoning was 27%. Students usually used two or three informal reasoning patterns together. Most of the students took more consideration on social factors. Some perceived ethical and moral implications of the issues, but they did not consider them seriously. They made their decisions depending on their own values, etc. 65% of the participants got their information on socioscientific issues from the mass media. Biology majors hardly used intuitive reasoning compared to non-biology majors. The Biology major group took into deep considerations on socioscientific issues while the non-biology major group seemed to interpret the given scenarios simply. This implied that the content knowledge was a significant factor of their decision-making. Therefore, it is necessary to develop proper science courses for non-major students to improve their decision-making on socioscientific issues. So, when we develop educational materials or programs, we should consider students' reasoning patterns, their considerations in decision-making, and their content knowledge. And because the mass media has the potential to play a key role for an effective education, we need to make a plan to make a practical application.

• 정보보호학회논문지
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• 제23권1호
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• pp.11-18
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• 2013

실행코드의 변조와 역분석 방지를 위해 단순히 선행블록에서 암, 복호화 키를 얻던 기존의 기법과 달리, 암호학적 MAC함수를 이용한 암호화기법과 코드 블록 간 중요도에 따라 상관관계를 설정하고 상관관계에 따라 암, 복호화 키를 생성하는 새로운 변조 방지 기법을 제안한다. 본 논문에서는 기존의 해쉬함수 대신 암호학적 MAC함수를 사용하고 MAC함수의 키를 동적으로 생성하는 방법을 소개한다. 또 단순히 선행블록의 해쉬 값에서 키를 얻는 것이 아니라 실행 코드 블록을 중요도에 따라 중요도 높음, 중간, 낮음으로 분류하고 중요도 높음 블록은 암호화하고 중요도 중간 블록은 중요도 높음 블록의 키를 생성시키는 블록으로 분류한다. 또 중요도 낮음 블록은 아무 처리도 하지 않음으로 소프트웨어 효율성을 고려한다. 기존 해쉬함수 대신 동적으로 생성되는 링크키를 이용한 MAC함수와 블록상관관계를 함께 사용함으로써 공격자의 분석을 어렵게 한다.

• Journal of Gastric Cancer
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• 제20권3호
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• pp.290-299
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• 2020

Purpose: Recently, totally laparoscopic gastrectomy has been gradually accepted by surgeons worldwide for gastric cancer treatment. Complete dissection of the lymph nodes and the establishment of the surgical margin are the most important considerations for curative gastric cancer surgery. Previous studies have demonstrated that indocyanine green (ICG)-traced laparoscopic gastrectomy significantly improves the completeness of lymph node dissection. However, it remains difficult to identify the tumor location intraoperatively for gastric cancers that are staged ≤T3. Here, we investigated the feasibility of ICG fluorescence for lymph node mapping and tumor localization during totally laparoscopic distal gastrectomy. Materials and Methods: Preoperative and perioperative data from consecutive patients with gastric cancer who underwent a totally laparoscopic distal gastrectomy were collected and analyzed. The patients were categorized into the ICG (n=61) or the non-ICG (n=75) group based on whether preoperative endoscopic mucosal ICG injection was performed. Results: The ICG group had a shorter operation time and less intraoperative blood loss. Moreover, significantly more lymph nodes were harvested in the ICG group than the non-ICG group. No pathologically positive margin was found and there was no significant difference in either the proximal or distal surgical margins between the 2 groups. Conclusions: Near-infrared fluorescence imaging with ICG can be successfully used in totally laparoscopic distal gastrectomy, and it contributes to both the completeness of D2 lymph node dissection and confirmation of the gastric transection line. Well-designed prospective randomized studies are needed in the future to fully validate our findings.

• 한국문헌정보학회지
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• 제58권1호
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• pp.373-393
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• 2024

본 연구는 음악저작의 우선표제 기술 지침 개발시 고려사항을 제안하고자 RDA 규칙을 분석하고, 여러 국가 도서관의 지침을 분석하였다. 우선, RDA 규칙을 분석하고, 규칙의 별법 및 선택사항별로 자체적인 지침을 개발한 8개 국가도서관에서 RDA 적용 지침을 조사하여 주요 고려대상 규칙을 살펴보았다. 이후 규칙별로 MLA, LC-PCC, DACH의 지침 내용을 분석하여 고려사항을 실질적으로 제시하였다. 첫째, 우선표제 선정과 관련하여 원어표제를 채택하도록 하되 원어표제가 국내 이용자에게 적합하지 않은 경우, 다른 언어의 우선표제를 사용하도록 할 필요가 있다. 둘째, 우선표제 기술과 관련하여 한 파트 저작, 둘 이상의 파트를 가진 저작, 한 저자의 전집, 특정 작곡유형명의 전집, 불완전한 합집, 여러 작곡가의 합집으로 나누어 살펴보았다. 셋째, 추가요소로 연주수단, 숫자표시, 음조, 기타 식별특성을 우선표제 기록시 고려사항으로 제시하였다. 넷째, 작곡유형명과 연주수단을 위한 통제어휘집을 지정하거나 제시할 필요가 있다. 본 연구는 RDA 음악저작의 우선표제 기술 지침 개발시 고려할 사항을 제시하였으므로 음악저작의 우선표제 관련 규칙 개발과 도서관에서 음악저작의 우선표제 기술 지침 작성에 기여할 수 있을 것이다.

• Structural Engineering and Mechanics
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• 제63권4호
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• pp.509-519
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• 2017

Wind field in mountainous regions demonstrates unique distribution characteristic as compared with the wind field of the flat area, wind load and wind effect are the key considerations in structural design of television towers situated in mountainous regions. The television tower to be constructed is located at the top of Xiushan Mountain in Nanjing, China. In order to investigate the impact of terrain factors of hilltops on wind loads, firstly a wind tunnel test was performed for the mountainous area within 800m from the television tower. Then the tower basal forces such as bending moments and shear strength were obtained based on high frequency force balance (HFFB) test. Based on the experiments, the improved method for determining the load combinations was applied to extract the response distribution patterns of foundation internal force and peak acceleration of the tower top, then the equivalent static wind loads were computed under different wind angles, load conditions and equivalent goals. The impact of terrain factors, damping ratio and equivalent goals on the wind load distribution of a television tower was discussed. Finally the equivalent static wind loads of the television tower under the 5 most adverse wind angles and 5 most adverse load conditions were computed. The experimental method, computations and research findings provide important references for the anti-wind design of high-rise structure built on hilltops.

• Wind and Structures
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• 제31권3호
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• pp.269-285
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• 2020

The statistical characteristics of typhoon wind speed records tend to have a considerable time-varying trend; thus, the stationary wind model may not be appropriate to estimate the wind characteristics of typhoon events. Several nonstationary wind speed models have been proposed by pioneers to characterize wind characteristics more accurately, but comparative studies on the applicability of the different wind models are still lacking. In this study, three landfall typhoons, Ampil, Jongdari, and Rumbia, recorded by ultrasonic anemometers atop the Shanghai World Financial Center (SWFC), are used for the comparative analysis of stationary and nonstationary wind characteristics. The time-varying mean is extracted with the discrete wavelet transform (DWT) method, and the time-varying standard deviation is calculated by the autoregressive moving average generalized autoregressive conditional heteroscedasticity (ARMA-GARCH) model. After extracting the time-varying trend, the longitudinal wind characteristics, e.g., the probability distribution, power spectral density (PSD), turbulence integral scale, turbulence intensity, gust factor, and peak factor, are comparatively analyzed based on the stationary wind speed model, time-varying mean wind speed model and time-varying standard deviation wind speed model. The comparative analysis of the different wind models emphasizes the significance of the nonstationary considerations in typhoon events. The time-varying standard deviation model can better identify the similarities among the different typhoons and appropriately describe the nonstationary wind characteristics of the typhoons.