• Nuclear Engineering and Technology
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• 제48권6호
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• pp.1412-1422
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• 2016

Austenitic stainless steels (ASSs) are widely used for nuclear pipes as they exhibit a good combination of mechanical properties and corrosion resistance. However, high tensile residual stresses may occur in ASS welds because postweld heat treatment is not generally conducted in order to avoid sensitization, which causes a stress corrosion crack. In this study, round robin analyses on stress intensity factors (SIFs) were carried out to examine the appropriateness of structural integrity assessment methods for ASS pipe welds with two types of circumferential cracks. Typical stress profiles were generated from finite element analyses by considering residual stresses and normal operating conditions. Then, SIFs of cracked ASS pipes were determined by analytical equations represented in fitness-for-service assessment codes as well as reference finite element analyses. The discrepancies of estimated SIFs among round robin participants were confirmed due to different assessment procedures and relevant considerations, as well as the mistakes of participants. The effects of uncertainty factors on SIFs were deducted from sensitivity analyses and, based on the similarity and conservatism compared with detailed finite element analysis results, the R6 code, taking into account the applied internal pressure and combination of stress components, was recommended as the optimum procedure for SIF estimation.

• International Journal of Computer Science & Network Security
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• 제22권6호
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• pp.57-62
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• 2022

The recent past has seen a tremendous amount of advancement in the field of Internet of Things (IoT), allowing the influx of a variety of devices into the market. IoT devices are present in almost every aspect of our daily lives. While this increase in usage has many advantages, it also comes with many problems, including and not limited to, the problem of security. There is a need for better measures to be put in place to ensure that the users' data is protected. In particular, fitness trackers used by a vast number of people, transmit important data regarding the health and location of the user. This data is transmitted from the fitness device to the phone and from the phone onto a cloud server. The transmission from device to phone is done over Bluetooth and the latest version of Bluetooth Light Energy (BLE) is fairly advanced in terms of security, it is susceptible to attacks such as Man-in-the-Middle attack and Denial of Service attack. Additionally, the data must be stored in an encrypted form on the cloud server; however, this proves to be a problem when the data must be decrypted to use for running computations. In order to ensure protection of data, measures such as end-to-end encryption may be used. Homomorphic encryption is a class of encryption schemes that allow computations on encrypted data. This paper explores the application of homomorphic encryption for fitness trackers.

• 대한간호학회지
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• 제37권4호
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• pp.490-500
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• 2007

Purpose: The purpose of this study was to identify factors influencing the outcome of psychosocial rehabilitation for persons with chronic mental illness and to suggest a hypothetical model of psychosocial rehabilitation which is based on the relationship between influencing factors and then to test its fitness empirically. Method: Data was collected from persons with a chronic mental illness using a self-report questionnaire, and from their case managers using an observed rating questionnaire. A total of 220 cases were used in the final analysis, and a hypothetical model was verified through covariance structure analysis using LISREL. Result: 1) The fitness indices of the model were $X^2=133.77$ (df=48, p=.00), GFI=0.93, AGFI=0.87, RMR=2.32, NNFI=0.95 and NFI=0.95. Twelve paths among fifteen proved to be significant. 2) Psychosocial rehabilitation was influenced directly by symptoms, daily living skill and self-concept, and was influenced indirectly by the psychosocial rehabilitation program service. Psychosocial rehabilitation accounted for 32% of variance of these factors. Conclusion: This study is expected to contribute to understanding the psychosocial rehabilitation phenomena. Besides it will provide basic information for developing strategies of bio-psycho-sociological interventions and evaluations in regard to influential factors of psychosocial rehabilitation.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 추계학술대회
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• pp.784-786
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• 2016

최근 건강과 관련된 다양한 시스템들에 대한 연구가 진행되고 있다. 이에 반해 사용자의 신체 정보를 정확하게 분석하고 이에 따른 정보를 제공해주는 시스템들은 개발 단계이거나 정확도가 미흡한 수준이다. 이를 해결하기 위해 본 논문에서는 사용자의 신체 정보를 분석하는 알고리즘을 제시하고 이를 기반으로 한 피트니스 시스템을 제안한다. 사용자의 신체 정보를 분석하는 알고리즘은 사용자의 신장과 체중을 분석하여 BMI(Body Mass Index) 지수와 BMR(Basal Metabolic Rate) 수치를 계산한다. 제안하는 시스템은 계산된 BMI 지수와 BMR 수치를 바탕으로 사용자에게 적합한 운동량을 추천해줄 수 있을 것으로 사료된다.

• 통상정보연구
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• 제14권1호
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• pp.391-418
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• 2012

최근의 소셜 네트워크 서비스 (Social Network Service)는 그 사용범위와 목적이 확장하고 있다. 초기의 이메일, 리스트서브, 뉴스그룹 등 비교적 동질적 집단 간의 네트워킹 중심의 SNS로부터, 이제는 기업들에게도 게시판, 개인의 미니홈피나 블로그, Facebook, Twitter를 이용한 소셜미디어 마케팅이라는 개념이 형성되고 있다. 본 연구에서는 소셜미디어 활용과 수출마케팅 성과의 관계성을 검증하는 것이 목적이다. 이를 위하여 SNS활용의 유형을 살펴보고, 이들과 수출마케팅 성과와의 관계를 검증하고자 하였다. 연구결과, SNS활용은 수출마케팅 성과와 직접적인 영향을 미치는 것으로 분석되었다. 또한 제품의 온라인 적합성과 조직의 혁신수용성은 SNS활용에 긍정적인 영향을 미치는 것으로 도출된 반면, 마케팅역량과 국제화역량은 SNS활용을 통하여 수출마케팅성과로 이어지지 않는다고 파악되었다. 따라서 SNS의 활용을 증진시킬 수 있는 제품과 서비스의 개발과 함께, 조직 내부의 SNS활용에 대한 적극적 관심과 수용이 필요하다는 점을 시사하고 있다.

• 융합정보논문지
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• 제8권1호
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• pp.95-103
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• 2018

본 논문에서는 보행속도, 주야간 인구변화, 보행경로에 따른 서비스 권역 등을 고려하여 대피시설 위치에 대한 적절성을 평가하고자 하였다. 보행속도는 선행연구사례를 통해서 1.6 m/s, 2.22 m/s를 정의하였고, 주야간 인구변화는 대시메트릭 매핑기법을 이용하여 인구를 추정하였다. 보행속도와 보행경도에 따른 대피시설 서비스 권역은 입지할당모형의 네트워크 분석을 실시하였다. 그 결과 시공간 유동인구 변화와 보행속도에 따라 일부 대피시설의 경우 수용능력에 한계가 있음을 알 수 있었고 이에 대한 대피시설 추가지정이 요구된다.

• Computers and Concrete
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• 제10권6호
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• pp.587-607
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• 2012

The purpose of this research is to propose a design technique of concrete mix proportions satisfying service life through genetic algorithm (GA) and neural network (NN). For this, thirty mix proportions and the related diffusion coefficients in high performance concrete are analyzed and fitness function for diffusion coefficient is obtained considering mix components like w/b (water to binder ratio), cement content, mineral admixture (slag, flay ash and silica fume) content, sand and coarse aggregate content. Through averaging the results of 10 times GA simulations, relative errors to the previous data decrease lower than 5.0% and the simulated mix proportions are verified with the experimental results. Assuming the durability design parameters, intended diffusion coefficient for intended service life is derived and mix proportions satisfying the service life are obtained. Among the mix proportions, the most optimized case which satisfies required concrete strength and the lowest cost is selected through GA algorithm. The proposed technique would be improved with the enhancement of comprehensive data set including wider the range of diffusion coefficients.

• 한국정보통신학회논문지
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• 제18권6호
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• pp.1475-1480
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• 2014

Fitness 센터 이용자들은 자신에게 맞지 않은 기구를 선택함으로써 부상의 위험이 존재했고 효율적인 운동 방법을 익히기 위해서는 오랜 시간이 필요했다. 이를 해결하기 위해 사람들은 퍼스널 트레이닝을 이용하지만 값비싼 비용의 문제가 발생하고 혼자 운동하는 습관을 기르는데 어려움을 갖게 했다. 본 논문에서는 다양한 스마트 폰 플랫폼과 호환성을 가진 하이브리드 앱 기반으로 개인화된 트레이닝 마켓 시스템을 구축하였다. 사용자들은 Fitness 센터에서 자신의 운동 기록을 스마트 폰의 하이브리드 앱을 활용해 가속도 센서를 활용하여 입력하거나 직접 입력하는 방식으로 웹에 전송한다. 이를 기반으로 사용자들에게 맞는 운동 프로그램을 웹에 있는 트레이닝 마켓을 통해 제공하게 된다. 퍼스널 트레이닝 마켓에는 다양한 사용자들이 운동 기록을 확인하여 그에 대한 운동 프로그램을 추천할 수 있고 스스로 선택하여 적용할 수 있다. 이를 통해 사용자는 자신에게 맞는 운동 프로그램으로 장기간 운동할 수 있는 습관을 기를 수 있고 능동적인 목표 설정이 가능하다.

• International Journal of Knowledge Content Development & Technology
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• 제12권1호
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• pp.7-16
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• 2022

With the proliferation of activity-tracking devices and other smart tools, more users leverage these personal informatics technologies to track their physical and fitness-related activities. The research on the benefits (and limitations) of these devices tends to focus on the use of a single tool, leaving out the interactions among multiple technologies, and how these interactions influence the way users perceive their affordances. Building from an ecological perspective, I extend this research by providing insight into the competitive and complementary relationships among activity tracking devices and other fitness-related and personal informatics technologies within the device ecology of technologies around the user. The affordances of these devices are therefore not enacted in isolation but are relational to understanding of other technological options and differing personal preferences and goals of the user.

• 한국생활과학회지
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• 제18권2호
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• pp.407-418
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• 2009

In our modern society along with high speed economic growth and improvement of living conditions and through concentration of people in cities cars became essential necessities for people living in modern society. Due to social and economic conditions and for the need of recycling of materials and as a countermeasure for waste of materials importance of car service is stressed. In this connection need for improvement of working clothes which are suitable for safety and working efficiency in a difficult working environment is essential. However most of working clothes now being sold in the market are produced without consideration of ergonomic aspects of wearers of working clothes. For this reason there is need for basic research on development of working clothes which improve safety and comfort for working of car service workers. Accordingly in this study this author carried out research on fitness, level of satisfaction and dissatisfaction, suitability for movement and level of demand for improvement in working clothes with focus on workers at car service firms and direction for its improvement was explored. This study is intended to provide basic data for development of functional pattern of working clothes for car service workers in future.