• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.435-436
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• 2020

본 논문에서는 단상 영구자석 동기 전동기의 센서리스 운전을 위한 회전자 자극 검출 기법을 제안한다. 제안한 회전자 초기 자극 검출 방법은 비대칭 공극을 갖는 단상 영구자석 동기 전동기에 고주파 전압 및 옵셋 전류를 인가하여 회전자 자극 위치에 따른 전류 옵셋의 크기를 검출함에 있다. 이를 위해 가상의 dq축 모델을 이용한 고정자 전류의 크기를 비교하여 회전자 자극을 검출하고자 한다. 제안된 방법은 다수의 실험 결과를 통해 타당성을 입증하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.390-392
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• 2022

기계학습 분야에서 모델을 학습시키려면 많은 양의 데이터가 필요하다. 최근에는 컴퓨터 비전 분야에서 데이터가 적은 환경에서 모델을 학습하는 다양한 방법들이 소개되고 있다. 하지만 대부분의 방법을 사용하기 위해서는 어느 정도 최소한의 학습 데이터가 필요하기 때문에 극심하게 데이터가 부족한 환경에서는 사용하기 어렵다. 본 논문에서는 컴퓨터 비전 분야에서 기계학습을 사용할 때 극심하게 데이터가 부족한 환경에서 시뮬레이션 도구를 활용한 인조 데이터 생성 방법을 제안한다. 실험 결과를 통해 시뮬레이션 도구를 활용하여 생성한 인조 데이터로 학습한 모델이 실제 데이터만을 학습한 모델을 대체할 수 있음을 확인하였고, F-1 점수와 정확도가 향상함을 실험적으로 확인하였다.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.371-372
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• 2023

If the participants in construction site safety management perform their duties in accordance with the provisions of the Industrial Safety and Health Act, the burden on safety managers would be minimal. However, the lack of specific work guidelines for each participating entity and the greater responsibility of the safety and health general manager than the management supervisor have resulted in safety managers' workload being increased due to the problem of management supervisors' neglect of safety management. In this study, we conducted a survey of the safety manager's duties and related documents during the construction project initiation, early stages, ongoing work, and disaster occurrence/investigation, and conducted interviews to improve and enhance the division of duties.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.11a
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• pp.376-377
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• 2023

스마트홈은 기술 시스템, 자동화 프로세스, 원격 제어 기기 등을 아파트나 주택에서 사용하는 것을 말한다. 주요 목적은 가정에서 삶의 질과 편의성을 높이는 것이다. 현재의 스마트홈은 사용자의 원격 제어 방식을 사용하고 있다. 이러한 방식은 고정된 시간에만 스마트홈이 작동하도록 한다는 문제가 있었다. 연관분석과 순차분석을 통해 AI가 상황과 사용자의 취향을 학습한다면, 스스로 최적화된 패턴을 제공할 수 있을 것이다.

• Journal of Internet of Things and Convergence
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• v.6 no.1
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• pp.45-53
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• 2020

This study aimed to examine the relationship of the knowledge of end-of-life(EOL) care, life-sustaining treatment(LST), and advance directive(AD) with the educational needs regarding AD writing among nurses in convergence era. For this cross-sectional study, participants were 169 nurses at a general hospital in South Korea. Data were collected from July 19 to 26 in 2018 using structured questionnaires. Knowledge on EOL care scored 8.56 out of 11 points, knowledge on LST scored 5.11 out of 6 points, and knowledge on AD scored 8.02 out of 9 points. Educational needs regarding AD writing scored 4.31 out of 5 points. There were statistically correlations between knowledge on LST and educational needs regarding AD writing (r=.182, p=.018), and between knowledge on AD and educational needs regarding advance AD writing (r=.234, p=.002). The findings can be used to develop the educational program regarding AD.

• Nuclear Engineering and Technology
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• v.52 no.3
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• pp.469-476
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• 2020

Research reactors in-core experimental facilities are designed to provide the highest steady state flux for user's irradiation requirements. However, fuel conversion from highly enriched uranium (HEU) to low enriched uranium (LEU) driven by the ongoing effort to diminish proliferation risk, will impact reactor physics parameters. Preserving the reactor capability to produce the needed flux to perform its intended research functions, determines the conversion feasibility. This study investigates the neutron flux in the central experimental facility of two material test reactors (MTR), the IAEA generic10 MW benchmark reactor and the 22 MW s Egyptian Test and Research Reactor (ETRR-2). A 3D full core model with three uranium enrichment of 93%, 45%, and 20% was constructed utilizing the OpenMC particle transport Monte Carlo code. Neutronics calculations were performed for fresh fuel, the beginning of life cycle (BOL) and end of life cycle (EOL) for each of the three enrichments for both the IAEA 10 MW generic reactor and core 1/98 of the ETRR-2 reactor. Criticality calculations of the effective multiplication factor (K_eff) were executed for each of the twelve cases; results show a reasonable agreement with published benchmark values for both reactors. The thermal, epithermal and fast neutron fluxes were tallied across the core, utilizing the mesh tally capability of the code and are presented here. The axial flux in the central experimental facility was tallied at 1 cm intervals, for each of the cases; results for IAEA 10 MW show a maximum reduction of 14.32% in the thermal flux of LEU to that of the HEU, at EOL. The reduction of the thermal flux for fresh fuel was between 5.81% and 9.62%, with an average drop of 8.1%. At the BOL the thermal flux showed a larger reduction range of 6.92%-13.58% with an average drop of 10.73%. Furthermore, the fission reaction rate was calculated, results showed an increase in the peak fission rate of the LEU case compared to the HEU case. Results for the ETRR-2 reactor show an average increase of 62.31% in the thermal flux of LEU to that of the HEU due to the effect of spectrum hardening. The fission rate density increased with enrichment, resulting in 34% maximum increase in the HEU case compared to the LEU case at the assemblies surrounding the flux trap.

• Journal of the Society of Naval Architects of Korea
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• v.49 no.2
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• pp.174-181
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• 2012

In this paper, the Flow Control Fin(FCF) optimization has been carried out using computational fluid dynamics(CFD) techniques. This study focused on evaluation for the performance of the FCF attached in the stern part of the ship. The main advantage of FCF is to enhance the resistance performance through the lift generation with a forward force component on the foil section, and the propulsive performance by the uniformity of velocity distribution on the propeller plane. This study intended to evaluate these functions and to find optimized FCF form for minimizing viscous resistance and equalizing wake distribution. Four parameters of FCF are used in the study, which were angle and position of FCF, longitudinal location, transverse location, and span length in the optimization process. KRISO 300K VLCC2(KVLCC2) was chosen for an example ship to demonstrate FCF for optimization. The optimization procedure utilized genetic algorithms (GAs), a gradient-based optimizer for the refinement of the solution, and Non-dominated Sorting GA-II(NSGA-II) for Multiobjective Optimization. The results showed that the optimized FCF could enhance the uniformity of wake distribution at the expense of viscous resistance.

• The Journal of Society for e-Business Studies
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• v.4 no.3
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• pp.25-42
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• 1999

As todays manufacturers and business organizations are struggling to compete in the global marketplace, they are concentrating on the efficient use of numerous information on design, development production, testing, distribution, and maintenance of products throughout their whole life cycles. To meet these organizations demands on information integration, the CALS has been recently focused as a dominant philosophy. In this paper, we introduce the computer supports for engineering CALS in which the engineering process at an initial phase of product development is simultaneously and collaboratively peformed. The proposed system supports the following functions: a virtual prototyping, a distributed collaborative design, and engineering information management. We have conformed to CORBA (Common Object Request Broker Architecture) standard to support interoperability between distributed objects and have used JAVA to support cross-platform and distributed user access to the system on the Web. Under this system, multidisciplinary design teams in engineering CALS environment can collaboratively perform their tasks, share design information and communicate with each other on the Web.

• Journal of the Korean Society of Food Culture
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• v.6 no.2
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• pp.141-146
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• 1991

This is a study about Jangs presented in the Cheminyosul. Scattered yeast and purified salts are used as ingredients of Jangs. Hwangeui, Hwangjeung and Eol are scattered yeast, and Sangmanyom, Hwayom and Inyom are purified salts. According to their main ingredient, Jang can be classified Kokjang, Yukjang and Eojang. Kokjang was made from soybean and/or wheat, Yukjang made from meat, and Eojang made from fish and crustacea. Eojang is similar to Korean fish sauce, Jeot. Three kinds of Kokjang, four kinds of Yukjang and seven kinds of Eojang are described in the Cheminyosul. Generally, Jangs were fermented and ripened for one day to one hundred days. Also, most of Jangs were made in cold season except Keonjeeojang and Janghae.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.26.1-26.1
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• 2011

We investigated the atomic layer deposition (ALD) process for nitrogen doped ZnO and the application for n-ZnO : N/p-Si (NW) coaxial hetero-junction photodetectors. ALD ZnO:N was deposited using diethylzinc (DEZ) and diluted $NH_4OH$ at $150^{\circ}C$ of substrate temperature. About 100~300 nm diameter and 5 um length of Si nanowires array were prepared using electroless etching technique in 0.108 g of $AgNO_3$ melted 20 ml HF liquid at $75^{\circ}C$. TEM images showed ZnO were deposited on densely packed SiNW structure achieving extraordinary conformality. When UV (360 nm) light was illuminated on n-ZnO:N/p-SiNW, I-V curve showed about three times larger photocurrent generation than film structure at 10 V reverse bias. Especially, at 660 nm wave length, the coaxial structure has 90.8% of external quantum efficiency (EQE) and 0.573 A/W of responsivity.