• Asia pacific journal of information systems
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• 제1권1호
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• pp.5-16
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• 1991

Business firms have been expressing a strong interest in an effective structure of computing resources. In this respect previous studies provide some guidelines about the deployment of hardware, but the question of which information systems (IS) would be run under the dispersed hardware is still unanswered. The main purpose of the study is to analyze the relationship between various IS characteristics and the distribution of IS. The IS characteristics studied in this research include the usage frequency of IS in a dispersed plant, the currency of information required by the headquarter, the data volume processed in the plant, the relatedness of IS with other information systems in the plant. The survey was performed over the domestic, large manufacturing firms. The most noticeable finding is that the more the updated information is required in the headquarter, or the more related IS is to other information systems in the plant, the more IS is distributed.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.387-392
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• 2008

Next Generation High Speed Train having a distributed electrical motor system has just been developing to aim the experimental maximum speed at 400km/h since August, 2007. This project is in stage of concept design and so, it needs to take some review and analysis the characteristics of suspensions on the view of concept design. A train dynamic modeling is modified with the one car model presented in the previous conference and it was extended to 6cars models having the same suspensions and added some connection's characteristics between the cars with Vampire program. It is used to analyze the effect on the dynamic performances according to the variation of primary and secondary suspension characteristics in the condition of 6 cars configuration. The results would be useful to manage the potential risks in the next stage of basic and critical design that will be done by the manufacturing company.

• 공업화학
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• 제34권3호
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• pp.226-240
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• 2023

This paper provides an overview of the trends and future directions in the development of anode materials for solid oxide fuel cells (SOFCs) using hydrocarbons as fuel, with the aim of enabling a decentralized energy supply. Hydrocarbons (such as natural gas and biogas) offer promising alternatives to traditional energy sources, as their use in SOFCs can help meet the growing demands for energy. We cover several types of materials, including perovskite structures, high-entropy alloys, proton-conducting ceramic materials, anode on-cell catalyst reforming layers, and anode functional layers. In addition, we review the performance and long-term stability of cells based on these anode materials and assess their potential for commercial manufacturing processes. Finally, we present a model for enhancing the applicability of fuel cell-based power generation systems to assist in the realization of the H₂ economy as the best practice for enabling distributed energy. Overall, this study highlights the potential of SOFCs to make significant progress toward a sustainable and efficient energy future.

• International journal of advanced smart convergence
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• 제12권2호
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• pp.173-181
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• 2023

Data collection is an essential element in the construction and operation of a smart factory. The quality of data collection is greatly influenced by network conditions, and existing wireless network systems for IoT inevitably lose data due to wireless signal strength. This data loss has contributed to increased system instability due to misinformation based on incorrect data. In this study, I designed a distributed MQTT IoT smart sensor and gateway structure that supports wireless multicasting for smooth sensor data collection. Through this, it was possible to derive significant results in the service latency and data loss rate of packets even in a wireless environment, unlike the MQTT QoS-based system. Therefore, through this study, it will be possible to implement a data collection management system optimized for the domestic smart factory manufacturing environment that can prevent data loss and delay due to abnormal data generation and minimize the input of management personnel.

• 한국조경학회지
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• 제41권5호
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• pp.46-56
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• 2013

본 연구는 야외 운동기구에 대한 안전기준이 마련되어 있으며, 제품 안전검사를 평가하는 TUV 기준을 적용하여 국내 거주지 주변에 보급된 야외 운동기구 제품의 안전성 실태를 규명하고 평가하는 것을 목적으로 하고 있다. 그리고 조달 판매량이 많은 12업체를 선정하고, 판매 선호도가 높은 10개의 야외 운동기구 제품을 대상으로 현장조사를 통해 평가한 결과, 안전성 평가 요구조건에 대한 야외 운동기구 평균 합격률이 55.1%로 평가되었다. 그리고 야외 운동기구의 고정상태에 대한 요구조건은 안전성이 높게 평가되었지만, 이용되는 유동 상태에 대한 요구조건은 안전성이 낮은 것으로 밝혀졌다. 또한, 판매 선호도가 높은 운동기구 제품이 다른 제품에 비교하여 안전성이 낮게 평가되었으며, 제작 업체에 따른 안전성 평가의 차이는 없는 것으로 분석되었다. 이러한 결과는 국내에서 보급되는 운동기구의 안전성이 높다고 볼 수 없으며, 향후 이용 중의 사고예방을 위해 법제정을 통한 안전기준 마련의 시급성을 시사하고 있다고 사료된다. 이러한 안전기준 마련은 사고예방뿐만 아니라, 야외 운동기구의 제작 업체의 경쟁력 강화에도 영향을 미칠 것으로 판단된다.

• Restorative Dentistry and Endodontics
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• 제34권1호
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• pp.1-7
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• 2009

이 연구의 목적은 3차원 유한요소 모형 분석을 이용하여 삼각 대칭형과 5형태의 단면 및 변형된 사각 형태인 장방형 단면으로 분류되는 네 종류의 니켈티타늄 파일이 만곡 근관 적용 시의 응력 분포를 비교하는 것이다. 삼각 대칭형 단면 구조의 ProFile #30 / .06과 Heroshaper #30 / .06, 장방형 단면구조의 Mtwo #30 / .05와 NRT #30/ .06 파일을 마이크로컴퓨터 단층촬영을 하고 reverse engineering을 통하여 파일의 구조를 얻고 삼차원 유한요소모형을 제작하였다. 모형 근관 내에서 파일이 근관장끝까지 진입하여 회전할 때 발생하는von Mises 응력 분포 및 파일의 제거후의 잔류 음력의 분포양상을 ABAQUS 프로그램을 이용하여 비교하였다. 근관 내 회전 시에 발생하는 응력을 관찰하였을 때 NRT 파일에서 가장 큰 응력을 나타냈으며, 각 파일에서의 최고 응력과 최저 응력을 비교하였을 때 Mtwo파일에서 가장 큰 차이가 나타났다. 응력의 내부 분포 경향을 보았을 때 장방형 구조의 단면을 가진 Mtwo 및 NRT 파일에서 불연속적인 응력의 집중 부위가 관찰되었으며, 근관 외부로 파일을 제거하여 탄성 회복이 일어난 후의 잔류 응력도 NRT 파일에서 가장 높게 나타났다. 이상의 결과로 유추할 때, 삼각대칭 단면 구조를 가진 파일보다 S-형태의 단면과 변형된 사각 형태의 단면 등의 장방형 단면 구조의 파일이 파절의 위험성이 더 클 것으로 사료된다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 추계학술발표대회
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• pp.31.2-31.2
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• 2011

We studied a method of manufacturing an anode to restrict contraction in reducing NiO/YSZ by uniformly mixing. In order to mix Ni and YSZ, a sub-micron Ni core surface was coated at high-speed by a mixture of nano-sized YSZ and a spherical core-shell was subsequently formed. The micron-sized core-shell anode powder was then heat treated at $400{\sim}1,450^{\circ}C$ in an air atmosphere and Ni was extruded and synthesized in nano-size. Subsequently, when the nano-sized mixture of the anode was heat treated and maintained at a temperature of $1,450^{\circ}C$, the anode was manufactured, where Ni and YSZ were uniformly distributed with the nano-structure. According to the nano-sized anode powder synthesis process, Ni particles were oxidized at $400{\sim}500^{\circ}C$ and became spherical by surface tension. In the case of the spherical core Ni powder, the heat treatment temperature rose to $1,250^{\circ}C$ and then a gap between the internal and external pressures occurred due to thermal and tensile stresses. A crack subsequently appeared on the surface, and the heat treatment temperature was increased continuously to increase the pressure gap and then the core Ni extruded as a nano-sized powder, Ni and YSZ uniformly distributed. It was found that the anode of 50~200 nm with a consistent structure obtained in this study has electric conductivity that is approximately 3 times larger than that of a commercial anode.

• 한국정보과학회논문지:시스템및이론
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• 제33권1_2호
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• pp.44-51
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• 2006

본 논문에서는 동시공학적 생산개념을 부재 생산자동화에 적용시킨 웹 기반의 통합 네스팅 시스템을 제안한다. 일반적으로 판재 부재 생산 공정은 정해진 순서에 따라 순차적으로 진행된다. 그러나 본 논문에서는 이들 공정들의 특성을 분석하여 클라이언트/서버 환경에서 운용될 수 있도록 분산 설계하였다. 그리고 판재 부재 생산에 필요한 부재 CAD, 네스팅, 부재 CAM, NC포스트프로세서 기능들을 웹 환경에서 다수의 작업자가 시스템에서 일괄 처리할 수 있도록 구현하였다. 개발된 시스템은 기존의 상용시스템에 비해 생산 자동화의 통합작업 환경을 제공할 수 있고, 작업자간의 공동작업이 가능하며, 작업대기 시간을 단축할 수 있음을 입증하였다. 본 논문은 부재생산 자동화분야에 컴퓨터 시스템 기술들을 접목함으로서 공장자동화의 효율성과 생산성 향상에 기여할 수 있음을 증명하였다.

• 대한방사선기술학회지:방사선기술과학
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• 제43권1호
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• pp.9-14
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• 2020

Commercial plate bolus is generally used for treatment of surface tumor and required surface dose. We fabricated 3D-printed bolus by using 3D printing technology and usability of 3D-printed bolus was evaluated. RT-structure of contoured plate bolus in the TPS was exported to DICOM files and converted to STL file by using converting program. The 3D-printed bolus was manufactured with rubber-like translucent materials using a 3D printer. The dose distribution calculated in the TPS and compared the characteristics of the plate bolus and the 3D printed bolus. The absolute dose was measured inserting an ion chamber to the depth of 5 cm and 10 cm from the surface of the blue water phantom. HU and ED were measured to compare the material characteristics. 100% dose was distributed at Dmax of 1.5 cm below the surface when was applied without bolus. When the plate bolus and 3D-plate bolus were applied, dose distributed at 0.9 cm and 0.8 cm below the surface of the bolus. After the comparative analysis of the radiation dose at the reference depth, differences in radiation dose of 0.1 ~ 0.3% were found, but there was no difference dose. The usability of the 3D-printed bolus was thus confirmed and it is considered that the 3D-printed bolus can be applied in radiation therapy.

• Journal of Acupuncture Research
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• 제27권2호
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• pp.105-113
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• 2010

Objectives : This study was performed to analyze the quality of Ojeok-san extract powders distributed in Korea. Methods : HPLC analyses of Ojeok-san decoction produced in laboratory and 8 kinds of Ojeok-san extract powders were done. Also, quantity analyses of paeoniflorin in Paeonia lactiflora, Glycyrrhizin in Glycyrrhiza uralensis, alkaloid in Ephedra sinica, Hesperidin in Citrus unshiu Markovich, and cinnamic acid in Cinnamomum cassia Blume were performed to investigate the accurate content of 6 kinds of Ojeok-san extract powders. Results : In the pattern analysis, the peaks were compared. The content of components in herbal extract powders was 14.7 to 15.8% of that of decoction in average. The range was measured from 8.5 to 25.7%. The pattern comparison showed significant differences among the pharmaceutical companies' products. As for the quantity analysis, one of herbal extract powder contained insufficient amount of Paeonia lactiflora components and one of herbal extract powder was in short of Ephedra sinica components. All of the others contained more than standard component(over 90%). Conclusions : Because herbal extract powders are also medicine, standardized manufacturing methods and consistent quality management are necessary. Therefore exaction and operation of national standards and various researches to improve the quality management of herbal extract powders is urgent.