• Journal of the Korean Vacuum Society
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• v.19 no.4
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• pp.256-264
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• 2010

In this paper, a digital controller of magnetic bearing system for a high vacuum turbomolecular pump (TMP) is designed and examined. For stabilizing and providing damping in magnetic bearing, the digital PID controller is applied for each 5 control axes, and the inter-axis cross feedback controller is also applied to suppress low frequency vibration caused by gyroscopic moment of the rotor at high speed of rotation. The fabricated rotor-shaft has its first flexible natural frequency lower than maximum speed, about 614Hz, so the two lead filters are applied to increase damping of flexible mode. Notch filters with rotating frequency were selected to reduce vibration of the pump housing caused by unbalance load. The implemented controllers are verified by examination of frequency response and rotating test up to 40,000 rpm, which is higher than critical speed of backward flexible mode.

• Land and Housing Review
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• v.11 no.2
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• pp.95-104
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• 2020

This study aims to explore a purely mechanistic pavement analysis approach where viscoelasticity and fracture of asphalt mixtures are considered to accurately predict deformation and damage behavior of flexible pavements. To do so, the viscoelastic and fracture properties of designated pavement materials are obtained through experiments and a fully mechanistic damage analysis is carried out using a finite element method (FEM). While modeling crack development can be done in various ways, this study uses the cohesive zone approach, which is a well-known fracture mechanics approach to efficiently model crack initiation and propagation. Different pavement configurations and traffic loads are considered based on three main functional classes of roads suggested by FHWA i.e., arterial, collector and local. For each road type, three different material combinations for asphalt concrete (AC) and base layers are considered to study damage behavior of pavement. A concept of the approach is presented and a case study where three different material combinations for AC and base layers are considered is exemplified to investigate progressive damage behavior of pavements when mixture properties and layer configurations were altered. Overall, it can be concluded that mechanistic pavement modeling attempted in this study could differentiate the performance of pavement sections due to varying design inputs. The promising results, although limited yet to be considered a fully practical method, infer that a few mixture tests can be integrated with the finite element modeling of the mixture tests and subsequent structural modeling of pavements to better design mixtures and pavements in a purely mechanistic manner.

• Journal of Aerospace System Engineering
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• v.14 no.6
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• pp.18-25
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• 2020

This study investigated the structural behaviors and safety of an electro-mechanical linear actuator and a load simulator with a plate spring. The material and dimensions of the plate spring were determined by theoretically calculating the stress and torsional angle for the rating load of the actuator. Thereafter, a flexible multibody dynamics (FMBD) analysis was conducted on the linear actuator and load simulator to confirm the performance of the load simulator and acquire the reaction forces acting on the actuator and simulator. The structural safety of the linear actuator and load simulator was evaluated via finite element analysis using the aforementioned reaction forces. Consequently, the proposed linear actuator and load simulator were determined to be structurally safe; however, the safety factors for the actuation rod and the housing on the actuator were excessively high. Therefore, the weight and cost must be reduced to improve their design parameters in the future.

• Journal of the Korean housing association
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• v.17 no.2
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• pp.87-96
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• 2006

Since the idea of registering architectural heritage from the early 20th century was introduced as part of the code in the Cultural Heritage Protection Law in July, 2001, more systematic and flexible application the code has been in great demand. It is the aim of this thesis that we preserve modern buildings and then use this research data what find our modern history. So we should find connection of modem and tradition with the overcome of the feeling of being victimized. Accordingly, based on preservation cases and finding of modern house heritage, it is the aim of this thesis that we find the way of the best use. The purpose of this research is to establish a more comprehensive and commonsensical guideline for the preservation of modern architecture satisfying both the government and the registering party, based on more thorough architectural analysis of residential edifices. The results of this study were as follows: (1) It is necessary for application and conservation by point, area and network method. (2) It is needed that periodically check and record central system for the purpose of the management of those. (3) It's consider that develop of conservation method on co-ownership with citizen by house personality.

• Journal of the Korean Home Economics Association
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• v.47 no.10
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• pp.97-108
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• 2009

As one of the conservation strategies, the city of Jeonju established regulations to conserve and revitalize the Hanok village as an attractive tour site. Some of old traditional houses were renovated into traditional inns. A couple of traditional houses were additionally built for lodging houses. The need for urban rehabilitation and adaptive re-use has been growing in Jeonju province. The purpose of this study was to examine how the traditional houses were converted into lodging places balancing the conflict issues such as preserving the unique characteristics of Hanok and updating functional requirement of modern lodging in terms of sustainable reuse and development. For this study, site visits and intensive interview with the owners of the seven traditional lodges were conducted. There was lack of guidelines and strategies renovation or rehabilitation of Hanok as lodging facility for sustainable use and revitalization of city. For the seven traditional Hanok inns, layout of rooms characterized as separate and disconnected, while traditional houses were open, flexible and connected regarding room arrangement. In addition, for sustainable development, the living environment of the community should be secured and align with developing strategies of the area.

• Journal of the Korea Furniture Society
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• v.23 no.4
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• pp.342-354
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• 2012

This study aimed at acknowledging characteristics of space usage and suggesting orientation of space planning and furniture designing that meet various residents' demands correlating with residential area, furniture and family members by doing fact finding of volume of the furniture in medium/small sized apartment. The contents of the study are "experience of functional remodeling," "a number of bedrooms correlating with a number of family" and "furniture arrangement of each space and characteristics of space utilization" based on forty six cases. Followings are results of the study. 1) It was acknowledged that the function of space relating to family members largely depends on furniture arrangement correlating with age of children. It is needed that flexible planning of residential area to meets growing children and various family demands. 2) Functional remodeling requires furniture rearrangement attended with the remodeling. Thus, it is required that ideas in more simple and efficient furniture designing and consideration of construction environment embracing that ideas. 3) It can be acknowledged that the most demanding matter to enjoy satisfied and comfortable life in residential area is the matter of storage area. It is also understandable that the matter can be worse by time going by and the change of living pattern. Therefore, it is required that the consideration of enough storage area compatible with its function of the room and the planning of built-in furniture for storage.

• Journal of Korea Trade
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• v.24 no.2
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• pp.15-30
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• 2020

Purpose - This paper investigates the theories and practices of Most-Favored-Nation (MFN) clauses. The MFN clause became a controversial issue during the past two decades, especially in the context of investment arbitration. This paper aims to clarify a reasonable way to apply MFN clauses. It in particular focuses on the territoriality requirements and the scope of investment activity which are common features included in most of investment treaties. Design/methodology - This paper analyses two investment arbitration cases, Ansung Housing and Beijing Urban Construction. Through the case study, this paper reveals limitations of the currently dominant views on the operation of MFN clauses. It then tries to reconstruct the system of MFN application within the relevant arbitration principles. Findings - Tribunals of recent investment arbitration as represented in the two cases above employed strict literal interpretation of the treaty provisions, especially of the phrase "in its territory". This paper finds a more functional interpretation is appropriate and consistent with theories of public international law and developments of global economy. Originality/value - Existing studies either stuck to literal interpretation or suggested more flexible interpretation of the phrase "in its territory" without full explanation. This paper tries to fill the gap in the existing discussion by analyzing legal foundations and theoretical structure for an effective interpretation of MFN clauses.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1068-1074
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• 2009

The progress is widely used as a critical index for successful construction project management. In spite of the importance of progress measurement, the excessive management effort to collect and maintain detailed data has been highlighted as a major barrier to measurement of highly accurate progress. In order to reduce the required workload and to enhance accuracy, several researches have been conducted. These researches can be categorized into two groups. First group focuses on automated data collection utilizing advanced technologies only for limited construction tasks. The second group is a research area where the standard progress measurement methodologies encompassing entire construction tasks are investigated. Topics include the adjusting the level of details, standardizing work processes, and applying flexible WBS. However, the techniques for automated data collection are not fully investigated yet in the second group. Combining these two research areas can provide a solution for more effective progress management in terms of enhancing accuracy and optimizing workload. However, there has been no comprehensive research addressing these two research groups in an integrated manner. In this context, the purpose of this paper is to propose a methodology that identifies the most suitable measurement method and data acquisition technology (e.g., GPS, RFID, etc.) for entire construction tasks of a project. The proposed methodology in this paper will be able to facilitate the selection process of data acquisition technologies for entire construction tasks of a project and to support the overall enhancement of automated progress management.

• Journal of the Korean housing association
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• v.25 no.5
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• pp.83-91
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• 2014

The main purpose of this research is to understand how the problems, which existing letter-shape houses have, are solved in Unjoru which is one of the letter-shape houses. Furthermore, there is the secondary purpose which is to realize the architectural characteristics of Unjoru through the process from the composition of rooms and buildings to the method of structure and roof formation. This research was approached in terms of architectural design, and as the result, the problems of the existing letter-shape houses was resolved by literally converting the shape of outdoor space to 品-shape form. Moreover through the result, it was recognized that the 占-Shape plan was flexible in responding to the demand of the times, such as the order of precedency within men and women and each generation. In addition to the previous results, it was confirmed that the location of major rooms was also decided by considering the interrelationship with natural environment of surrounding area. Also, in the whole proportion of building's plan, each building, such as ㄷ-shape Anchae and big-sized and middle-sized Sarangchae having 丁-shape form, and major rooms in the each building have proportion system such as 1:1, 3:4, $1:\sqrt{2}$, and 3:5 as aesthetic numerical value. Finally, it was understood that the architectural intention had double-sided characters, one side was authority and dignity in the aspect of shape and another side was practicality in aspect of inner housing life.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2006.05a
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• pp.193-196
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• 2006

The storage style has changed because of diversity of family types, improvement of cost of living, and increase of leisure time. In spite of this change, storage space has still caused discomfort since it did not consider residents' convenience. Therefore, in this study, Brand Apartments were selected, furniture detail drawing was analyzed by plan of housing size and zone to calculate storage area and capacity, and finally needs of storage space were analyzed using survey. Satisfaction of storage space was generally low and $20{\sim}30%$ increase of storage space was demanded. The reasons why the storage space was not satisfied are followed. First, storage space was insufficient. Second, the inner structure of storage space was unified. According to change of life style, needs have changed. To satisfy these needs, the inner division of storage space is planned with considering various items. In addition, development of hardware, flexible division, and priority of storage space with considering user's convenience are needed.