• 한국지반공학회논문집
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• 제33권4호
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• pp.25-34
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• 2017

불포화상태 지반의 흡수력과 응력변화를 반영한 토사사면의 전체 안정성 평가에서 매우 중요한 상태평가 입력변수로 함수특성곡선이 활용되고 있다. 함수특성의 경로의존성은 일반적으로 건조와 습윤과정으로 이력현상을 내포하는데 현장계측결과는 주로 실내실험의 습윤과정에 가깝게 나타난다. 본 연구에서는 이를 비정상류 해석에 적용하여 해석과 현장 계측된 결과들을 비교 검토하였다. 또한 심도가 증가할수록 강우의 영향이 작고 습윤과정을 적용해 산정된 값에 근접하였다. 따라서 불포화 토사사면 해석 시에 경로의존 함수특성곡선을 적용하여 안정성을 판단하는 것이 보다 합리적인 결과로 판단된다.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2003년도 추계국제학술대회
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• pp.91-93
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• 2003

It has been estimated that the equivalent of approximately $US 50 billion has been spent on research on the behavior and fate of pesticides in the environment since Rachel Carson published “Silent Spring” in 1962. Much of the resulting knowledge has been summarized explicitly in computer algorithms in a variety of empirical, deterministic, and probabilistic simulation models. These models describe and predict the transport, degradation and resultant concentrations of pesticides in various compartments of the environment during and after application. In many cases the known errors of model predictions are large. For this reason they are typically designed to be “conservative”, i.e., err on the side of over-prediction of concentrations in order to err on the side of safety. These predictions are then compared with toxicity data, from tests of the pesticide on a series of standard representative biota, including terrestrial and aquatic indicator species and higher animals (e.g., wildlife and humans). The models' predictions are good enough in some cases to provide screening of those compounds which are very unlikely to do harm, and to indicate those compounds which must be investigated further. If further investigation is indicated a more detailed (and therefore more complicated) model may be employed to give a better estimate, or field experiments may be required. A model may be used to explore “what if” questions leading to possible alternative pesticide usage patterns which give lower potential environmental concentrations and allowable exposures. We are currently at a maturing stage in this research where the knowledge base of pesticide behavior in the environmental is growing more slowly than in the past. However, innovative uses are being made of the explosion in available computer technology to use models to take ever more advantage of the knowledge we have. In this presentation, current developments in the state of the art as practiced in North America and Europe will be presented. Specifically, we will look at the efforts of the ‘Focus’ consortium in the European Union, and the ‘EMWG’ consortium in North America. These groups have been innovative in developing a process and mechanisms for discussion amongst academic, agriculture, industry and regulatory scientists, for consensus adoption of research advances into risk management methodology.

• 디지털융복합연구
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• 제18권10호
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• pp.517-526
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• 2020

본 연구는 미세먼지에 대한 위험인식태도와 불안이 미세먼지 예방행동의도에 미치는 영향을 확인하는 것을 목적으로 했다. 또한, 위험인식태도모델(RPA)의 적용대상과 범위를 확장하기 위해서 불안 변인을 추가하였다. 570명의 대학생을 대상으로 진행한 설문조사를 진행하였으며, 수집된 자료를 바탕으로 상관관계분석 및 일원배치분산분석, 삼원변량분석을 진행하였다. 분석 결과, 미세먼지에 대한 지각된 위험과 효능감이 예방행동의도와 정보추구의도에 통계적으로 유의미 한 것으로 나타났다. 불안도 예방행동의도와 정보추구에 유의미하게 영향을 주는 것으로 나타났다. RPA 모델의4 태도집단으로 구분하여 분석한 결과, 각 집단별로 예방행동의도와 정보추구의도에서 유의미한 차이를 보였으며, 불안요인이 일부 태도집단에 유의미한 영향을 주는 것으로 나타났다. 본 연구결과는 미세먼지 예방캠페인에서 태도집단에 맞는 메시지의 계획과 실행이 필요함을 시사한다. 후속 연구에서 사회심리학 변인 등의 영향을 고려한다면, 미세먼지 관련 건강행동을 파악하는데 도움이 될 것이다.

• 한국콘텐츠학회논문지
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• 제22권5호
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• pp.491-502
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• 2022

인간과 정보기기간 대화를 통해 물품을 구매하는 음성 쇼핑에 대한 관심이 증가하고 있다. 본 연구는 가치-태도-행동 모델을 활용하여 음성 쇼핑 지속이용의도에 미치는 영향 요인들을 살펴보았다. 인공지능 비서를 이용해 음성 쇼핑을 이용하고 있는 20-40대 소비자들을 대상으로 온라인 조사를 실시하였고, 총 360명의 응답 자료가 분석에 사용되었다. 데이터 분석을 위해 SPSS 25.0과 Amos 23.0 프로그램을 이용하였고, 기술통계분석, 확인적요인분석, 그리고 구조모형분석을 실시하였다. 본 연구의 결과는 다음과 같이 요약될 수 있다. 첫째, 기능적 가치가 음성 쇼핑에 대한 만족도에 가장 많은 영향을 미치는 것으로 확인되었다. 둘째, 사회적 가치, 감성적 가치, 그리고 진귀적 가치가 음성 쇼핑에 대한 만족도에 정(+)적인 영향을 미치는 것으로 확인되었다. 셋째, 음성 쇼핑의 만족도가 지속이용의도에 정(+)적인 영향을 미치는 것으로 확인되었다. 본 연구의 결과는 음성 쇼핑 이용자들에 대한 특성을 파악하고, 음성 쇼핑에서 추구되는 다양한 가치를 이해하는데 기여할 수 있을 것이다.

• 국제학술발표논문집
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• The 8th International Conference on Construction Engineering and Project Management
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• pp.75-84
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• 2020

Modular construction is a construction method whereby prefabricated volumetric units are produced in a factory and are installed on site to form a building block. The construction productivity can be substantially improved by the manufacturing and assembly of standardized modular units. 3D printing is a computer-controlled fabrication method first adopted in the manufacturing industry and was utilized for the automated construction of small-scale houses in recent years. Implementing 3D printing in the fabrication of modular units brings huge benefits to modular construction, including increased customization, lower material waste, and reduced labor work. Such implementation also benefits the large-scale and wider adoption of 3D printing in engineering practice. However, a critical issue for 3D printed modules is the loading capacity, particularly in response to horizontal forces like wind load, which requires a deeper understanding of the building structure behavior and the design of load-bearing modules. Therefore, this paper presents the state-of-the-art literature concerning recent achievement in 3D printing for buildings, followed by discussion on the opportunities and challenges for examining 3D printing in modular construction. Promising 3D printing techniques are critically reviewed and discussed with regard to their advantages and limitations in construction. The appropriate structural form needs to be determined at the design stage, taking into consideration the overall building structural behavior, site environmental conditions (e.g., wind), and load-carrying capacity of the 3D printed modules. Detailed finite element modelling of the entire modular buildings needs to be conducted to verify the structural performance, considering the code-stipulated lateral drift, strength criteria, and other design requirements. Moreover, integration of building information modelling (BIM) method is beneficial for generating the material and geometric details of the 3D printed modules, which can then be utilized for the fabrication.

• International Journal of Internet, Broadcasting and Communication
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• 제16권1호
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• pp.17-28
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• 2024

As listed as one of the most important requirements for Post-Quantum Cryptography standardization process by National Institute of Standards and Technology, the resistance to various side-channel attacks is considered very critical in deploying cryptosystems in practice. In fact, cryptosystems can easily be broken by side-channel attacks, even though they are considered to be secure in the mathematical point of view. The timing attack(TA) and the simple power analysis attack(SPA) are such side-channel attack methods which can reveal sensitive information by analyzing the timing behavior or the power consumption pattern of cryptographic operations. Thus, appropriate measures against such attacks must carefully be considered in the early stage of cryptosystem's implementation process. The Montgomery multiplier is a commonly used and classical gadget in implementing big-number-based cryptosystems including RSA and ECC. And, as recently proposed as an alternative of building blocks for implementing post quantum cryptography such as lattice-based cryptography, the big-number multiplier including the Montgomery multiplier still plays a role in modern cryptography. However, in spite of its effectiveness and wide-adoption, the multiplier is known to be vulnerable to TA and SPA. And this paper proposes a new countermeasure for the Montgomery multiplier against TA and SPA. Briefly speaking, the new measure first represents a multiplication operand without 0 digits, so the resulting multiplication operation behaves in a very regular manner. Also, the new algorithm removes the extra final reduction (which is intrinsic to the modular multiplication) to make the resulting multiplier more timing-independent. Consequently, the resulting multiplier operates in constant time so that it totally removes any TA and SPA vulnerabilities. Since the proposed method can process multi bits at a time, implementers can also trade-off the performance with the resource usage to get desirable implementation characteristics.

• 대한영양사협회학술지
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• 제14권2호
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• pp.166-175
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• 2008

The effects of nutrition label education on the perception, nutrition knowledge, understanding and applicability of labeling for 81 5$^{th}$ grade students was assessed. Prior to the education, the students' purchasing behavior of processed food was assessed by self-administered questionnaires. The evaluation of subjects' perception and understanding on nutrition label was completed prior to and following four education sessions utilizing materials developed by Korea Food and Drug Administration and Korea Health Industry Development Institute. More than 90% and 15% of subjects purchased processed food weekly and daily, respectively. Considering the nutrition label became an important factor in food purchases following the education sessions. Perception of the value of nutrition label improved from 2.93 to 3.32, although the belief that nutrition labels contributed to the maintenance of good food intake was not significantly increased. The total nutrition knowledge score increased from 5.47 to 7.14 and understanding nutrients composition table was significantly improved (3.17 to 4.80). The results indicate that a school-based nutrition label education program might be an effective aid for adoption of healthier food choices by children.

• Journal of Information Technology Applications and Management
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• 제14권1호
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• pp.179-202
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• 2007

This paper presents and tests a conceptual model of Technology Acceptance Model (TAM) that explains perceived usefulness, perceived ease of use, organizational commitment and turnover intention in terms of psychological commitments in mandatory environments. The model focuses on the psychological commitments (Kelman's internalization, Identification, compliance) as the primary predictors of perceived usefulness, perceived ease of use and organizational commitment. We discuss our current understanding of technology acceptance as well as the notion of mandated use. The results are as fellows that organizational commitment is negatively related to turnover intention : perceived usefulness is positively related to organizational commitment : psychological commitments are positively related to organizational commitment, perceived usefulness and perceived ease of use : perceived ease of use is positively related to perceived usefulness in mandatory environments. Through this research, psychological commitments are the strong determinants of technology acceptance in mandatory environments. These findings advance theory and contribution to the foundation for future research aimed at Improving our understanding of user adoption behavior in mandatory environments.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1991년도 봄 학술발표회 논문집
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• pp.41-48
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• 1991

In recent years, conskderable interest has developed in the fatigue strength of reinforced concrete members subjected to cyclic loading for the wide-spread adoption of ultimate strength design poecedures, the higher strength materials and the new recognition of the effect of repeated loading on structures such as bridges, concrete pavementes and offshore structures. In this study, a series of experiments is carried out to investigate the fatigue characteristics of deformed bars and underreinforced simply supported beams. The 69 reinforcing bar specimens with grade SD30 and designation of D16, D22, D25, and 24 beam specimens with D16 bars are prepared for this study. From these series of tests, it is found that I) a decrease of the bar deameter result in increased fatigue life, ii) the fatigue life of the bars embedded as main reinforcement within a concrete is more than that of bars in the air. iii) the fatigue strength at 2$\times$106 cycles of beams with steel ratio of 0.61% and 1.22% is 64.5% and 63.2% of the yielding strength, restectively. It is concluded that the low steel ratio has no significant effect on fatigue strength of underreinforced beams and the fatigue life of underreinforced concrete beams can be predicted conservatively by the fatigue life lf reinforcing bar.

• Asian Journal for Public Opinion Research
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• 제8권3호
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• pp.297-323
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• 2020

The relationship between compliance with behaviors recommended to prevent the spread of COVID-19 and media exposure, negative emotions, and risk perception was examined using regression analyses of data from KAMOS, a nationally representative survey of South Korean adults. The strongest predictor of preventive behaviors in general was negative emotions, which had the largest βh (.22) among the independent variables considered. The eight negative emotions, identified using factor analysis of a series of 11 emotions, were anger, annoyance, fear, sadness, anxiety, insomnia, helplessness, and stress. Negative emotions themselves were influenced most strongly by the respondent's anxiety over social safety (βe=.286), followed by prediction of COVID-10 spread (β=.121, p<.001) and perceived risk of COVID-19 infection (β=.70, p=.023). Females (β=-.134) and those who felt less healthy (βo=-.097) experienced more negative emotions. Media exposure and increased media exposure both have significant relationships with negative emotions and both a direct and indirect impact on the adoption of preventive measures. Women, older people, and healthier people perceived greater risks and engaged in more preventive behaviors than their counterparts.