• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.1
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• pp.104-111
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• 2017

This research focuses on simulation and visualization of flow field characteristics inside a centrifugal pump. The 3D numerical analysis was carried out by using a numerical CFD tool, addressing a Reynolds Average Navier-Stock code with a standard k-${\varepsilon}$ two-equation turbulence model. The simulation accounts for friction head loss due to rough walls at suction, impeller, discharge areas and volumetric head loss at impeller wear ring. A comparison of performance curves between simulation and experimentation is included, and it reveals a same trend of those results with a small difference of maximum 5 %. At best efficiency point, velocity vectors are smooth but it changes significantly under off-design point, a strong recirculation appears at the outlet of impeller passages near tongue area. A relatively uniform preassure distribution was observed around the impeller in despite of the tongue. Within the volute, because of its geometry, spiral vortexes formed, proving that the flow field in this region was relatively turbulent and unsteady.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2002.11a
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• pp.307-313
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• 2002

Urban style row-rise houses for rent have been supplied to the center of city from the 1950's first half The amount of stock is about 450,000 houses and occupies about 40％ in the private rented house. As for the structure, the 60％ of them is wooden-structure and the rest is non-wooden. Stocks of 57.5％ of the wooden-structure and 86％ of the non-wooden were built after 1981 years. It was 1981 years that the new earthquake-resistant standard was carried out, the improvement of stocks built before 1981 is necessary because those don't satisfy the present standard. To investigate the renovation possibility of urban style row-rise houses for rent, actual situation of two-story apartment at 2,4, and 5 Chome Taito-Ku in Tokyo was surveyed from July to November 2001. The number of building analyzed is 227 ridges among 234 ridges of the surveyed two-story building. 90％ of building analyzed is wooden structure. 1) The site of 88％ building surveyed is close to a road less than 4m width. It becomes the existing non-conformed building in the building construction act. It is impossible to make a renovation such as rebuilding, extension and remodeling because it requires the set back when renovating this type of non-conformed building, 2) The building built before 1981 is almost wooden-structure, and occupies 37％ of the building surveyed, and doesn't satisfy the present earthquake-resistant standard. An improvement of them is needed because the decrepitude of building proceeds. 3) 50％ of openings and 40％ of windows of the building surveyed doesn't use noncombustible materials. Though it becomes the existing non-conformed building, it can satisfy the present standard by replacing openings with noncombustible materials.

• International Area Studies Review
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• v.12 no.3
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• pp.195-216
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• 2008

It is generally accepted that the momentum strategies are effective in the short-term, and the contrarian strategies are profitable in the long run in major stock markets in the world. In Korean market, however, the contrarian is considered effective investment strategy both in the short- and long-term. We investigate whether this is true after 1999, and try to find out the reasons for this phenomena. We found that the contrarian strategies are still effective. Foreign investors showed consistent investment behavior both in Korean and abroad: they followed momentum in the short-tem, and contrarian in the longer-term. The individual investors, who are thought to be noise trader, showed different behavior. They followed contrarian strategies both in the short-and long-term. The reason that the contrarian is observed in Korean market regardless of the investment horizon is thought to be the irrtional behavior of individual investors.

• Advanced Industrial SCIence
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• v.2 no.1
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• pp.21-38
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• 2023

An attempt has been made in this article to discuss the fundamentals of technical analysis of the stock market. A retail investor or trader may not have the wherewithal to source that kind of information. Technical analysis requires a candlestick chart only. Most of the brokers in India provide charting solutions as well. Studying the price action of a security or commodity or Forex generally indicates a price pattern. Prices react at certain levels and widely known as support and resistance levels. Since whatever is happening with the price of the security is considered to be a part of a pattern or cycle which has already played out sometime in the past, these studies help a keen technical analyst to identify with certain probability, the future movement of the price. Study of the candlestick patterns, price action, volumes and indicators offer the opportunities to identify a high probability trade with probable target and a stop loss. A trader or investor can take high probability trade or position and control only her losses.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.8
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• pp.693-698
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• 2015

Recently, the quality of products after the corresponding machining processes were scrutinized in the interest of maintaining a high product-quality standard. The structure and stability of machine tools are important for the prediction of product quality. A structural analysis needs to be carried out to achieve the stable design of machine tools before the initial design stage in the manufacturing process of a precision product. In this study, a structural analysis was carried out using a finite element analysis (FEA) simulation to obtain the design stability of the main parts of a grinding machine. The sizes and locations of both the maximum stress and deformation in consideration of the cutting force of the chuck, tail stock, and bearing of the grinding machine were analyzed. Finally the grinding machine was successfully developed.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.2152_2153
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• 2009

In this study, the dynamic characteristic of a contact wire and pantograph suppling electrical power to high-speed trains are investigated from an electrical response point of view. To analysis power line disturbance by induced contact loss phenomenon for high speed operation, a hardware Simulator which considered contact loss between contact wire and the pantograph as well as contact wire deviation is developed. It is confirmed that a contact wire and pantograph model are necessary for studying the dynamic behavior of the pantograph system. One of the most important needs accompanied by increasing the speed of high-speed train is reduced that an arc phenomenon by loss of contact brings out EMI. In case of a high-speed train using electrical power, as comparison with diesel rolling stock, PLD(Power Line Disturbance) such as harmonic, transient voltage and current, EMI, dummy signal injection etc usually occurs. Throughout experiment, it is verified that an arc phenomenon is brought out for simulator operation and consequently conducted noise is flowed in electric circuit by power line disturbance.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.4
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• pp.427-431
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• 2009

In this study, the dynamic characteristic of a contact wire and pantograph suppling electrical power to high-speed trains are investigated from an electrical response point of view. To analysis power line disturbance by induced contact loss phenomenon for high speed operation, a hardware Simulator which considered contact loss between contact wire and the pantograph as well as contact wire deviation is developed. It is confirmed that a contact wire and pantograph model are necessary for studying the dynamic behavior of the pantograph system. One of the most important needs accompanied by increasing the speed of high-speed train is reduced that an arc phenomenon by loss of contact brings out EMI. In case of a high-speed train using electrical power, as comparison with diesel rolling stock, PLD(Power Line Disturbance) such as harmonic, transient voltage and current, EMI(Electromagnetic Interference), dummy signal injection etc usually occurs. Throughout experiment, it is verified that an arc phenomenon is brought out for simulator operation and consequently conducted noise is flowed in electric circuit by power line disturbance.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1304-1308
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• 2005

This paper presents the case that the existing analog control systems were retrofitted with digital DCS(Distributed Control System)s for boiler unit in thermal power plant. Replacement of existing worn-out or obsolete analog control systems has been considered. Replacement of existing analog control systems with another analog control systems has lots of difficulties in maintaining the systems due to being out of stock. Due to those difficulties, existing analog control systems have been retrofitted with digital DCSs in many industrial sites. KEPRI(Korea Electric Power Research Institute) accomplished the project that retrofitted analog control systems with the developed DCSs for boiler unit in middle-scale coal-fired thermal power plant. The benefits of an upgrade to digital control include a increase of reliability due to system redundancy, ease of modifying the control logic and the parameters of function block, ease of maintenance due to available spare parts, improvement of information display, ease of modifying MMI(Man Machine Interface) displays, a increase in system availability, and improvement of control performance. This paper describes how to use the parameters of existing analog controllers, the implementation of digital PID controller, control system configuration for boiler unit in thermal power plant, some boiler control loops, control result during commissioning, and the comparison of boiler characteristic test data after retrofitting with the existing test data.

• Land and Housing Review
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• v.5 no.3
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• pp.131-136
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• 2014

The Hong Kong Housing Authority (HKHA) develops and implements a public housing programme to meet the housing needs of people who cannot afford private rental housing. The HKHA has an existing stock of about 740,000 public rental flats (PRH). According to the 2014 Policy Address, the Government aims to provide an average of about 20,000 PRH units and about 8,000 Home Ownership Scheme (HOS) units per year. We care for the environment. In developing new housing estates, we conduct thorough environmental studies such as microclimate studies and air ventilation assessment, and use passive design to harness the natural characteristics of our sites. We employ environment-friendly design and construction methods, using modular flat design, pre-cast and pre-fabricated construction techniques as well as recycled, green construction materials. We conduct Carbon Emission Estimation for all our projects, conserve the use of natural resources and reduce wastes throughout the life cycle of buildings. We care for people. We adopt the principles of Universal Design and Barrier Free Access for the convenience and welfare of people of all ages and abilities. We carry out Community Engagement to collect stakeholders' views and aspirations, and incorporate them in the design of our projects. We also carry out surveys of residents' views after the occupation of new estates to gauge our success and identify areas for improvement.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.5
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• pp.81-90
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• 2020

This study investigates the nexus between the level of Corporate Social Responsibility Disclosures (CSRD) and Risk of Bankruptcy of companies that are listing in the Stock Exchanges of Vietnam. To investigate that relationship, this study collected secondary data from annual audited financial statements from 2014 to 2018 of listing companies. Applying two different regression models with two dependent variables and six independent and control variables, we find out that Vietnamese firms with higher level of CSRD performance can rapidly reduce their risk of bankruptcy. This phenomenon happens in the current year and in the coming years in all firms in the research sample. This result may be that the disclosures of social responsibility information can bring financial and non-financial benefits to the firms. In addition, the results also point out that there is a difference in risk of bankruptcy between the group of companies, which discloses and the one which does not disclose corporate social responsibility on their annual reports. This might be from the effects of various factors such as business size, financial leverage, market to book ratio, return on assets, cash flow from operations, etc. Our research results can be applied to other firms in Vietnam and in other similar jurisdictions.