• Carbon letters
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• v.23
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• pp.1-8
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• 2017

Polycrystalline diamond (PCD) tools possessing high hardness and abrasive wear resistance are particularly suited for drilling of carbon fiber reinforced plastic (CFRP) composites, where tool life and consistent hole quality are important. While PCD presents superior performance when drilling CFRP, it is unclear how it performs when drilling multi-stack materials such as CFRP-titanium (Ti) stacks. This comparative study aims to investigate drilling of a Ti plate stacked on a CFRP panel when using PCD tools. The first sequence of the drilling experiments was to drill 20 holes in CFRP only. CFRP-Ti stacks were then drilled for the next 20 holes with the same drill bit. CFRP holes and CFRP-Ti stack holes were evaluated in terms of machined hole quality. The main tool wear mechanism of PCD drills is micro-fractures that occur when machining the Ti plate of the stack. Tool wear increases the instability and the operation temperature when machining the Ti plate. This results in high drilling forces, large hole diameter errors, high surface roughness, wider CFRP exit thermal damage, and taller exit Ti burrs.

• Journal of the Society of Naval Architects of Korea
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• v.58 no.5
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• pp.303-313
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• 2021

Recently, quality control of the Liquefied Natural Gas Carrier (LNGC) cargo hold and block-erection interference areas using 3D scanners have been performed, focusing on large shipyards and the international association of classification societies. In this study, as a part of the research on LNGC cargo hold quality management advancement, a study on deep-learning-based scaffolding system 3D point cloud object detection and post-processing were conducted using a LNGC cargo hold 3D point cloud. The scaffolding system point cloud object detection is based on the PointNet deep learning architecture that detects objects using point clouds, achieving 70% prediction accuracy. In addition, the possibility of improving the accuracy of object detection through parameter adjustment is confirmed, and the standard of Intersection over Union (IoU), an index for determining whether the object is the same, is achieved. To avoid the manual post-processing work, the object detection architecture allows automatic task performance and can achieve stable prediction accuracy through supplementation and improvement of learning data. In the future, an improved study will be conducted on not only the flat surface of the LNGC cargo hold but also complex systems such as curved surfaces, and the results are expected to be applicable in process progress automation rate monitoring and ship quality control.

• Journal of Industrial Technology
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• v.26 no.A
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• pp.29-38
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• 2006

Efficiency and universality which was the spirit of the modern age, had also an enfluence on our living environment. Various types of individual housing unit were developed and mass-produced. However, the exterior space in our city is a place for our social life and intermediate place to connect the private life of each individual to our society. For the people to adapt themselves well to their environment, it should be well organized which means it is clearly divided and integrated in a hierarchical order. To realize these conditions, adequate boundaries to divide each territory and entrances to connect each territory are two essential elements. One of the possible methods to realize these conditions can be found in korean traditional architecture where the exterior space has the same figural quality like buildings and is the center of the whole composition. Buildings, walls and colonnades are the elements to define space. Gates, pavilions, gabs between buildings and posts are the elements to symbolize the entrance connecting each space. Each exterior space is integrated to a whole composition. One is the gradual differentiation along the axis which is unique in korean traditional architecture. The other is the rectangular connection which is also found in the other area in the world. The results of this thesis are as follows. The exterior space in the housing area should have the figural quality. The elements to make boundaries defining exterior space are classified into horizontal elements such as low buildings and walls, and vertical elements such as tower-shape buildings which define space in a different way. The position of openings in a housing block affects the characteristic and openness of a exterior space. Various types of gates are used to decide the relationship between spaces.

• KIEAE Journal
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• v.7 no.4
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• pp.45-50
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• 2007

The purpose of this research is to analyze the residential environment based on the physical quality indicators of green space in apartment housing through the case study of 36 housing estate samples which were built in 1994-1998. The contents of this research consists of two main parts. The first part is to analyze the characteristics of residential environment based on the quality indicators of green space in apartment housing. The second part is to analyze the Correlation of Development Conditions and Physical Quality Indicators of Green Space. This research will contribute to the establishment of the site planning methods which increase the quality of residential environment in apartment housing.

• The KIPS Transactions:PartB
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• v.12B no.4 s.100
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• pp.451-458
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• 2005

The transcoding is a solution which is able to adapt to heterogeneous clients of requesting a different playback rate of multimedia data. Thus, The transcoding needs decoding and encoding. In general, previous studies to reduce complexity have a problem, the degradation of visual quality On the contrary, previous studies to reduce the degradation of visual quality lead to heavy computation. Thus, many researchers have studied a solution between the complexity and the degradation of visual quality. But until now, most researches of this region have dealt with the transcoder itself, such researches about a server's assistance to improve the performance of transcoder is rarely studied. In case of servicing multimedia data to heterogeneous clients which have low capabilities, the assistance of server side is able to reduce frames with processing in the transcoder and improve the performance of the transcoder. Thus in this paper, we propose the frame-skipping transcoder system architecture that takes into consideration transcoder and server side to reduce the complexity of the transcoder.

• Journal of architectural history
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• v.1 no.2 s.2
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• pp.116-136
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• 1992

Architectural essence of John Ruskin's discourse can resolve itself into natural beauty, craftmanship, and truth in structure, surface, and process. His theories became disciplines of modern English school, Art and Craft and Free architecture, in aspects of organic architecture, morality, and rationality. These concepts disseminated continental Art Nouveau and also became it's basic principles. But his empirical theories hated use of machine, and should find a ideal model in medieval romanticism of Gothic. Anti-machine, as a instictive guideline of English modern architecture, couldn't cope with the industrialization of 20th century, and Gothic revival interfered with creating a new style. Muthesius' discourses were taught by the power of group movements and modern concept of form in English school, originally by Ruskin. But he accepted the potentiality of machine and mass production, and stressed creating the new German style suitable with machine. With the progress of Deutscher Werkbund, his theories were advanced to 'quality' connected with craftmanship, to discourse on mechanical 'form', and lastly to 'standardization and type' for mass production. Mechanical functionalism of Muthesius and DWB were sophiscated and handed down to Bauhaus, and then finally helped establishment of the Modern Architecture and Internationalism. Both English and German modern architecture owed their contribution as well as limitation to Ruskin and Muthesius as theorists. Through this comparative study, we can see the priority of theory to practice, the theoretical justification based on insight for its society and future, and the practical character of theory itself.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.5
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• pp.94-106
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• 2000

The purpose of this study is to provide the basic data for planning and designing Village Parks in Seoul in the future, which result from analyzing post-occupancy evaluation. For conducting this study, 10 Village Parks among 45, built between 1996 and 1997, were selected and analyzed. The results of this study are as follows. The degree of satisfaction of 10 Village Parks in Seoul has been evaluated on a scale of 10, to be a 6.68 average. This result means that the most respondents are satisfied with the existing Village Parks in Seoul. The correlation of the degree of satisfaction with major planning factors for 3 types of Village Parks shows that accessibility is the most important factor. As for future directions of planning and designing Village Parks, many kinds of sitting, leaning and resting place need to be provided. It is also necessary to improve the visual quality of the parks with various spatial elements. The research also shows that various facilities for people's use should be provided in Village Parks.

• Journal of the Korea Furniture Society
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• v.29 no.1
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• pp.31-39
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• 2018

Recently, as the continuously increasing of the one-person households, builders were focusing on a built-in furniture development for efficiency. Through the dead space of the space can be reduced. Also, Condensation that occurs in a built-in furnitures installation space may result in different results depending on the room's direction, floor, finish, adjacent room effect, occupant's lifestyle. In this background, it can be considered in terms of functional aspect and morphological aspect by using WUFI2D simulation system. As a result, the tendency of occurrence of condensation was examined by comparing the water content and the growth potential of fungus graph which came from WUFI2D. Results of this study are as followings: Built-in furniture, both top & bottom open, is more stable to condensation than the built-in furniture with the top or bottom open. Also, Among from the top floor built-in furniture to the bottom of it, the bottom one is more stable to condensation.

• Proceedings of the KWS Conference
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• 2006.10a
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• pp.216-218
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• 2006

The application of aluminium alloy is increasing for lightweight and high quality transport vehicle. In this study, therefore, it is intended to apply the high speed hybrid welding method for marine grade aluminium alloy(A5083) used for shipbuilding that consists of 3 kW CW Nd:YAG laser and MIG welding process. For this purpose, the characteristics of process parameters(laser & arc combine angle and focal position of hybrid head to specimen) are investigated for hybrid fillet joint. This study also describes determination of heat distribution using finite element model of the T-joint fillet weld using the in-house solver which has been validated for different type of welding problems.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.1
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• pp.60-67
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• 2007

The purpose of this study is to evaluate indoor air quality at the stage of building construction. To check the IAQ at the stage of construction IAQX simulation program developed by EPA was used and the values of TVOC were analyzed with time-series. The Simulation conditions are as follows. 1) Ventilation rate, 2) Time schedule of works, 3) Material change. Through this simulation, the major factors which affect the IAQ were analyzed and the importance of empirical data about the time-series emission rate of concerned material could be confirmed.