• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.04a
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• pp.362-369
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• 1997

In the case of a precision equipment, it requires a vibration free environment to provide its proper function. Especially, lithography and inspection devices, which have sub-nanometer class high accuracy and resolution, have come to necessity for producing more improved giga class semiconductor wafers. This high technology equipments require very strict environmental vibration standard in proportion to the accuracy of the manufacturing, inspecting devices. The vibration criteria of high sensitive equipment should be expressed in the form of 'exactness' and 'accuracy', because this is made basic data in the use of building structure design. This paper made a study on the specification of high sensitive equipment and proposed a contents of the specification.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2008.05a
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• pp.97-100
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• 2008

Commerce has been taking a part of important on composing structure and system, having been started with simple role on exchange goods. In this point, We can say that commerce is the condensation of life based on understanding human cultures. Commercial center has been changing on a form as well as a function all through the history, following the changes of society. The attentional point is that there are always entertainment factors and have the relationship with space of the building in constant The purpose of comsume is not only just for a product but also enjoy consuming time and space. Most people have concentration spending their free time city where they live. This study identify the entertainment factors for a commerce an entertainment center.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11b
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• pp.1376-1383
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• 2001

Modem technology depends on the reliability of extremely high technology equipments. In the production of semiconductor wafer, optical and electron microscopes, ion-beam, laser device must maintain their alignments within a sub-micrometer. This equipment requires a vibration free environment to provide its proper function. Especially, lithography and inspection devices, which have sub-nanometer class high accuracy and resolution, have come to necessity for producing more improved giga and tera class semiconductor wafers. This high technology equipments require very strict environmental vibration standard, vibration criteria, in proportion to the accuracy of the manufacturing, inspecting devices. The vibration criteria of high sensitive equipment should be represented in the form of 'exactness' and 'accuracy', because this is used as basic data for the design of building structure and structural dynamics of equipment. This paper deals with the properties of time and frequency domain in order to obtain more improved vibration criteria for high sensitive equipment.

• Journal of Korean Association for Spatial Structures
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• v.20 no.1
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• pp.31-40
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• 2020

The purpose of this study is to propose future-oriented high-rise buildings where the vehicle is parked at the top of the building. At the same time, the vehicle is used as a part of the building along with the advent of the era of autonomous driving. The suspended structure is proposed as a suitable structural system for architectural planning. This system is free to design because there are no limitations on column planning compared to conventional designs. In particular, the low-floor plan can be used as an open space because colums are not arranged in the lower-floors. Thereby opened low-floor plan has advantages that visual perception of the space is improved, noise problems along the side of the street is solved and planning underground parking spaces are easier. These advantages can solve the problem of overlapping columns with vehicle traffic in the building. However, there are some problems that the suspension structure is mainly a formal form and the usable area is small compared to the core area because it is a core-oriented structural system. In this regard, a new structural system was proposed by combining the concept of suspended structure and cable stayed column. Therefore, this paper analyzes the existing style of high-rise housing suspended Structure and proposes a new structural system and the concept of design for autonomous vehicles.

• Journal of the Korean Institute of Rural Architecture
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• v.12 no.4
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• pp.77-86
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• 2010

This study is about Tak Mok theory of feng-shui ideology which was main thought in Choson dynasty or some other thoughts and noble families' thought of garden building : planting trees and properties of the noble families garden. The result from the study of noble family's garden molding is as follows. In the noble family's garden molding, there were considerations of plant ecology known through long experience and the functional aspect of planting tree and esthetic sense of housing circumstances, in addition to feng-shui thought, Taoist thought and the doctrine of the five natural elements of the positive vs. negative. We can learn Choson's noble family's garden included playroom as well as symbolic and incantatory meaning. Also in the thought of noble family's garden molding we can found proper element for modern housing plan such as an ecological peculiarity or functional aspect of dwelling circumstance. And we can also found they didn't show a rejection symptoms against nature but enclosed with straight form which was traditional trait, and each space of it is composed organically. Also we knew they selected a diverse and refined technique with it's decorating the Choson dynasty playful and meditative space. We found that the key point of the thought of noble family's garden molding were on the basis of Confucianal mood, content amid poverty thought and free technique of it.

• Mass Spectrometry Letters
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• v.8 no.4
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• pp.90-97
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• 2017

Androgenic anabolic steroids (AASs) are synthetic derivatives of testosterone with a common structure containing cyclopentanoperhydrophenanthrene nucleus. Their use enhances the muscle building capacity and is beneficial during performance. The AASs are one of the most abused group of substances in horse doping. Liquid chromatography tandem mass spectrometry ($LC/MS^n$) has been successfully applied to the detection of anabolic steroids in biological samples. However, the saturated hydroxysteroids viz: nandrolone, $5{\alpha}-estrane-3{\beta}$, $17{\alpha}-diol$ exhibit lower detection responses in electrospray ionisation (ESI) because of their poor ionisation efficiency. To overcome this limitation pre-column chemical derivatization has been introduced to enhance their detection responses in $LC-ESI-MS^n$ analysis. The aim of present study was to develop a sensitive method for identification and confirmation of nandrolone and its metabolite in horse urine incorporating pre-column derivatization using picolinic acid. The method consists of extraction of targeted steroid conjugates by solid phase extraction (SPE). The eluted steroid conjugates were hydrolysed by methanolysis and free steroids were recovered with liquid-liquid extraction. The resulting steroids were derivatized to form picolinoyl esters and identification was done using LC-ESI-MS/MS in positive ionization mode. The picolinated steroid adduct enhanced the detection levels in comparison to underivatized steroids.

• Journal of the Korean Institute of Rural Architecture
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• v.14 no.4
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• pp.11-18
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• 2012

This study is to establish the dwelling principle and architectural characteristics of Powhatan Indian Community in Eastern part of North America. To find a pattern and dwelling principle of town building and housing, I have researched both site survey of Powhatan at Jamestown Settlement in Virginia and a related references of North America Indian. In addition of study, I have tried to understand their life style in 17C, a spatial characteristics of space composition, and a using materials of Yehakin which means Powhatan's house in the exhibition hall of Jamestown Settlement. The results of this paper are as follows: First, the form of Powhatan house is like a longhouse which has two types that are oblong and rectangular house. Usually they had lived in the style of oblong house. Second, there are three patterns to set up the semi-permanent settlement of Powhatan, which are circle-type, street-type, and free-type of village. Third, the fire place of interior space that is most importance element to heat and cook is put it into the center of room, and the other beds and shelves are arranged by the side of wall which is covered of rush matt.

• Journal of Korean Association for Spatial Structures
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• v.21 no.1
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• pp.105-112
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• 2021

In this paper, the dynamic response was analyzed by performing linear dynamic analysis using historic earthquake loads on twisted-shaped structures and fixed structure among free-form high-rise structures with atypical elevation shape following prior studies. In addition, the dynamic characteristics of the analysis models according to the plane rotation angle of the twisted structure were compared and analyzed. As a result of the analysis, as the plane rotation angle of the twisted structure increased, the interlayer deformation rate increased in the high-rise part of 50th floors or more. The story shear force and the story absolute acceleration were similar in the entire structure. In the case of the story shear force, the response of the twisted shape model was rather reduced in the middle part. As a result of analyzing the dynamic response, the vulnerable layer where the response amplification of the twisted structure occurs was found to be 31st story.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.2
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• pp.137-143
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• 2022

Composite materials, being light-weight and of high mechanical strength, are increasingly used in various industries such as the aerospace, automobile, sporting-goods manufacturing, and ship-building industries. Recently, manufacturing of composite materials using 3D printers has increased. 3D-printed composite materials are made in free-form and adapted for end-use by adjusting the fiber content and orientation. However, research on the machining of 3D printed composite materials is limited. The aim of this study is to develop a machine learning method to select machining conditions for machining of 3D-printed composite materials. The composite material was composed of Onyx and carbon fibers and stacked sequentially. The experiments were performed using the following machining conditions: spindle speed, feed rate, depth of cut, and machining direction. Cutting forces of the different machining conditions were measured by milling the composite materials. PCA, a method of machine learning, was developed to select the machining conditions and will be used in subsequent experiments under various machining conditions.

• Membrane Journal
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• v.33 no.1
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• pp.46-51
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• 2023

The purpose of this study is to analyze the utilization forms of hydrogen fuel cells, which are the core of building a smart city, and suggest ways to solve them. In the case of power plants to utilize hydrogen fuel cell, it was analyzed as the most promising form of use in the future due to the advantage of being free from intermittence problems. However, despite many advantages, local residents' opposition continues to emerge due to concerns about explosions and the problem of carbon dioxide generation in the case of certain hydrogen production methods, and it is analyzed that resolving them will be the main key to establishing the smart city. Finally, by analyzing the current hydrogen production method and identifying the problems facing it, the solution for the complete construction of the smart city was presented.