• 한국산업보건학회지
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• 제31권1호
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• pp.38-49
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• 2021

Objectives: This study was conducted to analyze the impact of safety/health managers' experience of trauma case on their post traumatic stress disorder and the mediation effects of job stress and the moderated mediation effects of social support. Method: Using a structured questionnaire, data were collected from 241 workplace safety/health managers with experience in trauma case. The collected data were analyzed using SPSS(IBM. Ver.26.0) and verified through SPSS PROCESS Macro (Ver. 3.4). Results: The trauma case experience and the job stress, which is a mediation variable, had a statistically significant positive effect on post-traumatic stress disorder, and the job stress had a positive mediation effect in the relationship between the trauma case experience and post-traumatic stress disorder. Social support had a statistically significant negative moderation effect in the relationship between the trauma case experience and job stress; social support had a moderated mediation effect on the indirect effect of a job stress on the post-traumatic effect through a trauma case experience. Conclusion: The above findings suggest that work-related job stress management is important in order to reduce safety/health managers' post-traumatic stress disorder caused by the experience of trauma case, and that social support is essential to reduce the job stress, which can later be used as a basis for further studies.

• 인터넷정보학회논문지
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• 제20권5호
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• pp.67-77
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• 2019

Today, companies are making efforts to improve the performance of workers by utilizing various IT-based mobile and internet devices. In pharmaceutical companies, salespeople are using the e-brochure to search for diverse expertise in real time. Through the e-brochure, pharmacists and doctors can be provided with the information they need, thereby increasing confidence in pharmaceuticals and salespeople. Salespeople can also use e-brochures to improve their work performance and to be more satisfied with their jobs. This study examines which functions of e-brochures satisfy salespeople and what attitudes to the e-brochures they need to have. This paper explains the effect of satisfaction and attitude to the e-brochures on job satisfaction through self-efficacy with statistical analysis. As a statistical result, the functions of e-brochures (professional knowledge, massive amount of data, easy searching, information updates, and the reflection of feedback) and attitudes to the e-brochures (importance, intention to use, belief in improvement, efficacy to use, and negative cognition) influence on self-efficacy of salespeople. Further, self-efficacy has mediating effects on the relationship between the functions of e-brochures / attitudes to e-brochures and job satisfaction. Exceptionally, the mediating effect of self-efficacy was not significant in relation to information updates / reflection of feedback and job satisfaction. These results will explain what functions should be focused for the future development of e-brochures. It will also suggest what attitudes the salespeople should have about e-brochures. Through these efforts, salespeople will be able to utilize new technology of e-brochures to satisfy their jobs and improve their performance.

• 한국측량학회지
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• 제38권6호
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• pp.499-509
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• 2020

본 연구에서는 최근 영상판독 분야에서 활발히 연구되고, 활용성이 발전하고 있는 인공지능 기반 객체분류 학습 데이터 구축에 관한 내용을 다룬다. 영상판독분야에서 인공지능을 활용하여 정확도 높은 객체를 인식, 추출하기 위해서는 알고리즘에 적용할 많은 양의 학습데이터가 필수적으로 요구된다. 하지만, 현재 공동활용 가능한 데이터 셋이 부족할 뿐만 아니라 데이터 생성을 위해서는 많은 시간과 인력 및 고비용을 필요로 하는 것이 현실이다. 따라서 본 연구에서는 소량의 초기 항공영상 학습데이터를 GAN (Generative Adversarial Network) 기반의 생성기 신경망을 활용하여 오버샘플 영상 학습데이터를 구축하고, 품질을 평가함으로써 추가적 학습 데이터 셋으로 활용하기 위한 실험을 진행하였다. GAN을 이용하여 오버샘플 학습데이터를 생성하는 기법은 딥러닝 성능에 매우 중요한 영향을 미치는 학습데이터의 양을 획기적으로 보완할 수 있으므로 초기 데이터가 부족한 경우에 효과적으로 활용될 수 있을 것으로 기대한다.

• 한국산학기술학회논문지
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• 제22권3호
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• pp.374-380
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• 2021

밴드 비트겐슈타인은 신해철이 이전에 결성했었던 대형 밴드 "넥스트" 이후 비교적 밴드의 형태를 갖춘 팀이다. 신해철 특유의 가사와 특정 컨셉이 돋보이는 이 앨범 또한 넥스트 앨범과 유사한 성향을 띄고 있다. 다만 샘플링과 컴퓨터음악을 바탕으로 다양한 형태의 밴드 사운드가 적절하게 융합을 이루고 있다는 점에서 그 차이점이 나타난다. 본 앨범은 300만원대의 비용으로 제작된 저예산 홈 레코딩 앨범으로 신해철은 메인보컬과 프로그래밍만 맡았고, 모든 작품들은 멤버가 함께 작업하였다. 이 앨범에서는 신해철 혼자만의 음악을 생산하기보다는 팀워크에 비중을 두어 멤버들과 공동 작업을 진행하였다. 앨범 녹음 저예산 홈 레코딩이 음악 생산에 제약이 될 수는 있었지만, 참신하고 매우 새로운 시도라는 점에서는 높이 평가받을 부분임을 틀림없는 사실이다. 음악을 창작하는 뮤지션들은 자신이 항상 선호하는 음악과 대중들이 선호하는 음악 사이에서 갈등을 초래한다. 그렇지만, 창작의 노력이 없으면 진화와 발전도 없다. 끊임없는 변화는 음악 능력을 계속해서 발전시킬 수 있으며, 이것은 한국대중음악의 발전으로 이어진다는 것은 분명한 사실이다.

• The Journal of Asian Finance, Economics and Business
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• 제8권3호
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• pp.297-305
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• 2021

A contractor or a main contractor is a company with full capacity to construct all project's works for the owner. A subcontractor is an organization that works with the main contractor to execute and complete work packages for the project. Selecting an effective subcontractor will help the efficiency and success of any projects in the construction industry. Therefore, this study identified subcontractor evaluation factors in Vietnam by collecting questionnaire survey data from engineers and staffs in the construction industry project environment. An exploratory factor analysis (EFA) was then performed to identify the critical factors when evaluating and selecting the subcontractor in construction projects. Moreover, when considering the impact level in terms of the average value, the research results showed that the most critical concern was the subcontractor's reputation. Furthermore, the top five factors affecting the sub-contractor evaluation and selection are (i) reputation, (ii) price, (iii) construction techniques, (iv) ability to implement projects according to commitments, and (v) subcontractor competence (the team of workers, technician staff, engineers with full capacity according to regulations). These research results provide an overall perspective that will help main contractors develop suitable subcontractors' evaluation and selection factors in their projects in the construction industry.

• 한국군사과학기술학회지
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• 제24권4호
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• pp.357-367
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• 2021

This paper studies the simulations of active airframe vibration controls for the Sikorsky X2 helicopter with a lift-offset coaxial rotor. The 4P hub vibratory loads of the X2TD rotor are obtained from the previous work using a rotorcraft comprehensive analysis code, CAMRAD II. The finite element analysis software, MSC.NASTRAN, is used to model the structural dynamics of the X2TD airframe and to analyze the 4P vibration responses of the airframe. A simulation study using Active Vibration Control System(AVCS) with Fx-LMS algorithm to reduce the airframe vibrations is conducted. The present AVCS is modeled using MATLAB Simulink. When AVCS is applied to the X2TD airframe at 250 knots, the 4P longitudinal and vertical vibration responses at the specified airframe positions, such as the pilot seat, co-pilot seat, engine deck, and prop gearbox, are reduced by 30.65 ~ 94.12 %.

• 공업화학
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• 제22권3호
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• pp.296-300
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• 2011

본 연구에서는 열병합 발전소의 원료로서 목질계 바이오매스로 임목 부산물, 폐목재, 야자수 부산물, 야자수 껍질의 연소 특성을 조사하기 위하여 열중량 분석기를 이용하여 연소 실험을 수행하였다. 목질계 바이오매스의 비교군으로는 일반적인 석탄을 사용하였다. 열중량 분석기 결과로부터, 목질계 바이오매스의 연소는 석탄과 비교하여 낮은 온도인 $280^{\circ}C$에서 $420^{\circ}C$ 구간에서 가장 활발한 연소반응을 보였음을 확인 할 수 있었다. 열중량분석에 의하여 측정된 활성화 에너지에 있어서 임목 부산물은 석탄 및 기타 목질계 바이오매스와 비교하여 가장 낮은 활성화 에너지 값을 나타내었으며, 또한 목질계 바이오매스의 경우 석탄과 비교하여 연소반응속도가 크게 증가함을 확인 할 수 있었다. 이는 목질계 바이오매스의 높은 연소개시 속도를 보이는 것을 나타내며, 이러한 결과는 석탄과 비교하여 낮은 비등점의 휘발분을 많이 포함하는 목질계 바이오매스의 특성에 기인하는 것으로 판단된다.

• Journal of the Korean Physical Society
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• 제73권9호
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• pp.1393-1398
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• 2018

In conventional single-photon emission computed tomography (SPECT), only the photoelectric events in the detectors are used for image reconstruction. However, if the $^{131}I$ isotope, which emits high-energy radiations (364, 637, and 723 keV), is used in nuclear medicine, both photoelectric and Compton scattering events can be used for image reconstruction. The purpose of our work is to perform simulations for Compton SPECT by using the Geant4 application for tomographic emission (GATE). The performance of Compton SPECT is evaluated and compared with that of conventional SPECT. The Compton SPECT unit has an area of $12cm{\times}12cm$ with four gantry heads. Each head is composed of a 2-cm tungsten collimator and a $40{\times}40$ array of CdZnTe (CZT) crystals with a $3{\times}3mm^2$ area and a 6-mm thickness. Compton SPECT can use not only the photoelectric effect but also the Compton scattering effect for image reconstruction. The correct sequential order of the interactions used for image reconstruction is determined using the angular resolution measurement (ARM) method and the energies deposited in each detector. In all the results of simulations using spherical volume sources of various diameters, the reconstructed images of Compton SPECT show higher signal-to-noise ratios (SNRs) without degradation of the image resolution when compared to those of conventional SPECT because the effective count for image reconstruction is higher. For a Derenzo-like phantom, the reconstructed images for different modalities are compared by visual inspection and by using their projected histograms in the X-direction of the reconstructed images.

• 한국폐기물자원순환학회지
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• 제35권8호
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• pp.777-784
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• 2018

Since climate change increases the risk of extreme rainfall events, concerns on flood management have also increased. In order to rapidly recover from flood damages and prevent secondary damages, fast collection and treatment of flood debris are necessary. Therefore, a quick and precise estimation of flood debris generation is a crucial procedure in disaster management. Despite the importance of debris estimation, methodologies have not been well established. Given the intrinsic heterogeneity of flood debris from local conditions, a regional-scale model can increase the accuracy of the estimation. The objectives of this study are 1) to identify significant damage variables to predict the flood debris generation, 2) to ascertain the difference in the coefficients, and 3) to evaluate the accuracy of the debris estimation model. The scope of this work is flood events in Ulsan city region during 2008-2016. According to the correlation test and multicollinearity test, the number of damaged buildings, area of damaged cropland, and length of damaged roads were derived as significant parameters. Key parameters seems to be strongly dependent on regional conditions and not only selected parameters but also coefficients in this study were different from those in previous studies. The debris estimation in this study has better accuracy than previous models in nationwide scale. It can be said that the development of a regional-scale flood debris estimation model will enhance the accuracy of the prediction.

• 정보보호학회논문지
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• 제31권3호
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• pp.353-363
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• 2021

언택트(Untact) 시대로의 급속한 변화 속에서 협업 툴(Collaboration Tool)은 비대면 업무를 위한 디지털 솔루션으로써 그 활용도와 가치가 증대되고 있다. 협업 툴은 다양한 기능을 지원하는 한편, 그 편의성에 비례하여 정보 유출, 보안사고 등 디지털 범죄 및 사고우려 또한 내재되어 있어 디지털 포렌식 관점에서의 연구가 필요하다. 본 연구에서는 세계적으로 점유율이 가장 높은 협업 툴 Microsoft Teams에 대한 윈도우즈 및 안드로이드 포렌식 연구를 통해 주요 사용자 행위를 정의하고 각 행위들을 수행한 뒤 의미 있는 아티팩트가 존재하는지 확인하였다. 이후 각 운영환경에서 획득 가능한 아티팩트를 비교·분석하고 여기에서의 차이점을 바탕으로 한 차분 포렌식(differential forensic)을 통해 협업 툴 분석기법 및 수사 시나리오 등 활용 방안을 제시하였다.