• Title/Summary/Keyword: semi-stability

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A Study on the Pungsu Landscape of the Myungdang Tomb Sites in Andong Area (안동의 풍수경관 연구 - 음택 명당을 중심으로 -)

  • 옥한석
    • Journal of the Korean Geographical Society
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    • v.38 no.1
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    • pp.70-86
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    • 2003
  • This study aimes to describe the forms and characteristics of Myungdang tomb sites in Andongs Area by conducting field trips and analyzing on topographic maps. Most Myundang sites are concentrated around hills, mountains, and tributaries that collectively are located in a northern parts of Nakdong river. The river and the mountain, which the principle of Pungsu, so called Jangpung and Duksu, is applied to, constitute the various forms. They provide the sites with physical settings for Myungdang that can be said to commonly retain such properties as semi-openness, multi-surroundedness, stability, harmony, balance. It can be further argued that those properties of Myungdang sites offer criteria for human settlement and sustainable land development in the current world.

AE Characteristic of Polyethylene Pipe under various defects (다양한 결함에 대한 폴리에틸렌 배관의 음향방출 특성)

  • Nam Ki Woo;Lee Si Yoon;Ahn Seok Hwan
    • Journal of the Korean Institute of Gas
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    • v.8 no.3 s.24
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    • pp.1-7
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    • 2004
  • The polyethylene pipe can use semi-permanent because of the high corrosion resistance with chemical stability. In addition to, there is the merit that is an easy to establish and to maintain. However, as the reason that it is simply degraded when the polyethylene pipe was exposed to the outside, mainly it is used to lay under the ground with low-pressure gas transportation pipe. In this study, the nondestructive evaluation method was used to maintain the integrity of the polyethylene pipe. We simulated the various defects on the polyethylene pipes, and then the AE signal occurred according to the impact test of steel ball was evaluated by the acoustic emission method. From the results, the waveform and dominant frequency could be distinguishing from the defect shapes of polyethylene pipe. Especially, in the case of notch defect, the AE signals occur different by the angle and depth of the notch.

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Measures of Reducing Traffic Accidents by Aging Bus Drivers (시내버스 운전자의 고령화에 따른 교통사고 저감대책 마련에 관한 실증적 연구)

  • Choi, Jae Won;Jung, Hun Young
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.3D
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    • pp.391-401
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    • 2011
  • The Implementation Semi-Public Management System of Intra-City Bus brings improvements of the position stability, work environment and welfare of the bus drivers. As these benefits prevent drivers' job changes, average age of the drivers increases. Some side effects such as fatality increase after the implementation of the new system are becoming social problems. To minimize such problems, it is necessary to prepare the measurements reflected drivers' age increase and driving characteristics of old drivers to decrease traffic accidents of intra-city buses. The existing measurements are mostly simple policy. To get over such limitations, this study grasped driving characteristics by surveys and driving aptitude test targeting old drivers and non-old drivers who brings about traffic accidents actually. As a result, the characteristics of the old drivers were understood precisely. The measures of decrease of the traffic accidents are suggested by the analysis of the behavior characteristics of the old drivers through the structural equation model.

Direct Strength Evaluation of the CVD SiC Coating of TRISO Coated Fuel Particle with Micro Hemi Spherical Shell Configuration (마이크로 반구 쉘 형상의 화학증착 탄화규소 TRISO 코팅층의 파괴강도 직접평가)

  • Lee, Hyeon-Keun;Kim, Do-Kyung
    • Journal of the Korean Ceramic Society
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    • v.44 no.7
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    • pp.368-374
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    • 2007
  • CVD-SiC coating has been introduced as a protective layer in TRISO nuclear fuel particle of high temperature gas cooled reactor (HTGR) due to its excellent mechanical stability at high temperature. In order to prevent the failure of the TRISO particles, it is important to evaluate the fracture strength of the SiC coating layer. It is needed to develop a new simple characterization technique to evaluate the mechanical properties of the coating layer as a pre-irradiation step. In present work, direct strength measurement method with the specimen of hem i-spherical shell configuration was suggested. The indentation experiment on a hemisphere shell with a plate indenter was conducted. The fracture strength of the coating layer is related with the critical load for radial cracking of the shell. The finite element analysis was used to drive the semi-empirical equation for the strength measurement. The SiC hemispherical shells were successfully recovered from the section-grinding of TRISO coated particle and successive heat treatment in air. The strength of CVD-SiC coating layer was evaluated from the experimentally measured critical load during the indentation on SiC hemisphere shell. Weibull diagram of fracture strength was also constructed. This study suggested a new strength equation and experimental method to measure the fracture strength of CVD-SiC coating of TRISO coated fuel particles.

The Simulation and Forecast Model for Human Resources of Semiconductor Wafer Fab Operation

  • Tzeng, Gwo-Hshiung;Chang, Chun-Yen;Lo, Mei-Chen
    • Industrial Engineering and Management Systems
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    • v.4 no.1
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    • pp.47-53
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    • 2005
  • The efficiency of fabrication (fab) operation is one of the key factors in order for a semiconductor manufacturing company to stay competitive. Optimization of manpower and forecasting manpower needs in a modern fab is an essential part of the future strategic planing and a very important to the operational efficiency. As the semiconductor manufacturing technology has entered the 8-inch wafer era, the complexity of fab operation increases with the increase of wafer size. The wafer handling method has evolved from manual mode in 6-inch wafer fab to semi-automated or fully automated factory in 8-inch and 12-inch wafer fab. The distribution of manpower requirement in each specialty varied as the trend of fab operation goes for downsizing manpower with automation and outsourcing maintenance work. This paper is to study the specialty distribution of manpower from the requirement in a typical 6-inch, 8-inch to 12-inch wafer fab. The human resource planning in today’s fab operation shall consider many factors, which include the stability of technical talents. This empirical study mainly focuses on the human resource planning, the manpower distribution of specialty structure and the forecast model of internal demand/supply in current semiconductor manufacturing company. Considering the market fluctuation with the demand of varied products and the advance in process technology, the study is to design a headcount forecast model based on current manpower planning for direct labour (DL) and indirect labour (IDL) in Taiwan’s fab. The model can be used to forecast the future manpower requirement on each specialty for the strategic planning of human resource to serve the development of the industry.

Optimized Decomposition of Ammonia Borane for Controlled Synthesis of Hexagonal Boron Nitride Using Chemical Vapor Deposition

  • Han, Jaehyu;Kwon, Heemin;Yeo, Jong-Souk
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.285-285
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    • 2013
  • Recently, hexagonal boron nitride (h-BN), which is III-V compound of boron and nitride by strong covalent sp2 bonds has gained great interests as a 2 dimensional insulating material since it has honeycomb structure with like graphene with very small lattice mismatch (1.7%). Unlike graphene that is semi-metallic, h-BN has large band gap up to 6 eV while providing outstanding properties such as high thermal conductivity, mechanical strength, and good chemical stability. Because of these excellent properties, hBN can potentially be used for variety of applications such as dielectric layer, deep UV optoelectronic device, and protective transparent substrate. Low pressure and atmospheric pressure chemical vapor deposition (LPCVD and APCVD) methods have been investigated to synthesize h-BN by using ammonia borane as a precursor. Ammonia borane decomposes to polyiminoborane (BHNH), hydrogen, and borazine. The produced borazine gas is a key material that is a used for the synthesis of h-BN, therefore controlling the condition of decomposed products from ammonia borane is very important. In this paper, we optimize the decomposition of ammonia borane by investigating temperature, amount of precursor, and other parameters to fabricate high quality monolayer h-BN. Synthesized h-BN is characterized by Raman spectroscopy and its absorbance is measured with UV spectrophotometer. Topological variations of the samples are analyzed by atomic force microscopy. Scanning electron microscopy and Scanning transmission Electron microscopy are used for imaging and analysis of structures and surface morphologies.

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Perception of Korean Hospital CEOs on Organizational Accountability : Findings from In-Depth Interviews (한국 병원 최고 경영자의 책무성 인식 : 심층 면접 결과를 중심으로)

  • You, Myoungsoon;Lee, Geunchan;Kwon, Soonman;Yoon, Hyejung
    • Health Policy and Management
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    • v.22 no.4
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    • pp.597-627
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    • 2012
  • As misalignments among images, identity, and legitimacy of health professionals and institutions have been on the rise, CEOs of health care organizations have been required to enhance organizational accountability. Despite the accumulation of literature on the conceptual discussions of accountability, only a few studies empirically investigated key barriers to accountability and its facilitators. To identify perception on accountability with key barriers and facilitators of organizational accountability, a semi-structured interview with 11 CEOs of Korean hospitals was conducted. A short survey was taken to get quantitative data on CEO's perception on organizational accountability. To CEOs, accountability was very complex and unfamiliar concept, but understood as physician's code of ethics by nature and basic principle of hospital management. CEOs thought accountability could be improved through ethical leadership, financial stability and learning climate of hospitals. Distrust of the government, which failed to provide economic incentives for hospitals to increase accountability activities, was emphasized as a serious barrier to hospital accountability. There was consensus among hospital CEOs as to the importance of accountability in management. However, there were concerns that, without policy instruments to motivate hospitals toward increasing community benefits as well as collective efforts among health professionals to rebuild moral climate for being accountable, greater accountability would not be achieved in hospitals.

The importance of maintaining 'enjoyment' from creative work - A discussion on the relationship between intrinsic motivation and creative labor (일로부터 추구하는 '재미'의 중요성 - 창의 노동과 내재적 동기의 관계에 대한 고찰)

  • An, Chairin
    • Review of Culture and Economy
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    • v.20 no.3
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    • pp.115-144
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    • 2017
  • This paper analyzes the actual 'content' and 'role' of the intrinsic motivation of creative laborers during the creative production process. Based on semi-structured intensive interviews with 16 light-entertainment television PDs in South Korea, this paper articulated that intrinsic motivation towards creative work could be understood as a desire to maintain their level of enjoyment from creative work. The desire was classified into two different types of 'enjoyment', one was the enjoyment based on the expectation regarding the creative job, and the 'enjoyment' experienced primarily related to the creative production process that allows creative workers to actualize individual creative ambitions. In addition, such intrinsic motivation tended to provide a strong driving force for creative workers as they endured unfavorable working conditions that resulted from market principles(viewership ratings), economic stability, and work-life balance. This paper proposes that the tendency of creative workers to endure various undesirable working conditions is based on a strong intrinsic motivation to maintain their level of enjoyment from their creative career.

Prototype Development of a Small Combine for Harvesting Miscellaneous Cereal Crops and its Basic Performance

  • Lee, Beom Seob;Yoo, Soonam;Lee, Changhoon;Yun, Young Tae
    • Journal of Biosystems Engineering
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    • v.43 no.4
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    • pp.311-319
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    • 2018
  • Purpose: The aim of this study is to develop a small combine for harvesting miscellaneous cereal crops. Methods: A prototype small combine was designed and constructed. Its specifications and basic performance were investigated. Results: The prototype small combine for harvesting miscellaneous cereal crops was designed and constructed to reflect similar specifications as those of the conventional combine. The prototype small combine comprises a diesel engine with the rated power/speed of 22.0 kW/2,600 rpm, three-stage primary and two-stage speed range transmission shifts, and a double acting threshing part. The maximum travel speeds of the prototype combine are approximately 0.72 m/s, 2.50 m/s, 0.30 m/s at the low, high speed range shifts in the forward direction, and while traversing in the reverse direction, respectively. The minimum radius of turning was approximately 1.50 m. In a static lateral overturning test, the prototype combine overturned neither to the right nor to left on a $30^{\circ}$ slope. The results of an oilseed rape harvesting test included the maximum operating speed of 0.32 m/s, the grain loss ratio of approximately 9.0%, and the effective field capacity of approximately 10.3 a/h. Additionally, among the outputs in grain outlet, the whole grains, damage grains, and materials other than grain (MOG) ratios accounted for 97.4%, 0.0%, and 2.6%, respectively. Conclusions: The prototype small combine for harvesting miscellaneous cereal crops indicates good driving ability and stability. The results of the oilseed rape harvesting test reveal that the harvesting performance must be enhanced such that the separating and cleaning parts are more suitable for each type of crop, thus reducing grain loss and foreign substances among the outputs in grain outlet. An improved small prototype combine could be used effectively to mechanize the harvesting of miscellaneous cereal crops in small family farms or semi-mountainous areas.

A Vision-based Pipe Support Displacement Measurement Method Using Moire Patterns (모아레 현상을 이용한 영상기반 파이프 서포트 변위측정 방법)

  • Park, Junbeom;Park, Semi;Kim, Jaehyeon;Kim, Jungyeol
    • Korean Journal of Construction Engineering and Management
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    • v.23 no.1
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    • pp.37-45
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    • 2022
  • It is very important to measure the displacement of a structure to evaluate the safety of the structure. This study shows a methodology to measure the displacement to determine the stability of a structure when it is damaged by loads. The methodology used Moiré's phenomenon and was verified through experiments. The experiments utilized pipes to simulate the pipe supports in the construction site and measured the vertical displacement of the Moiré interference patterns according to the horizontal displacement of the pipes. Experiments confirmed that the linear relationship between horizontal displacement of pipes and vertical displacement of Moiré patterns and derive a relational expression. In conclusion, the methodology presented in this work allows us to simultaneously measure a number of vertical members' displacements regardless of distance and determine the safety of the structure.