• Tunnel and Underground Space
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• v.3 no.1
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• pp.63-79
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• 1993

The design of tunnels in rock masses often demands more informations on geologic features and rock mass properties than acquired by usual field survey and laboratory testings. In practice, the situation that a perfect set of geological and mechanical input data is given to geomechanics design engineer is rare, while the engineers are asked to achieve a high level of reliability in their design products. This study presents an artificial neural network which is developed to resolve the difficulties encountered in conventional design techniques, particulary the problem of deteriorating the confidence of existing numerical techniques such as the finite element, boundary element and distinct element methods due to the incomplete adn vague input data. The neural network has inferring capabilities to identify the possible failure modes, support requirements and its timing for underground openings, from previous case histories. Use of the neural network has resulted in a better estimate of the correlation between systems of rock mass classifications such as the RMR and Q systems. A back propagation learning algorithm together with a multi-layer network structure is adopted to enhance the inferential accuracy and efficiency of the neural network. A series of experiments comparing the results of the neural network with the actual field observations are performed to demonstrate the abilities of the artificial neural network as a new tunnel design assistance system.

• Korean Institute of Interior Design Journal
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• v.24 no.3
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• pp.3-14
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• 2015

The most important issue of modern cities is a crime. Crime prevention through environmental planning is needed in the urban mixed-use commercial facilities which have an important role of modern urban life, and have a positive elements for local society. The purpose of this study is to propose a direction of crime prevention through environmental planning for the urban mixed-use commercial facilities. In order to accomplish this purpose, a questionnaire survey is performed on users of urban mixed-use commercial facilities to evaluate the importance and satisfaction. The conclusions are as follows; 1) Crime prevention through environmental planning is needed in the public space which forms boundary between urban mixed-use commercial facilities and other urban facilities. 2) Safety support planning is necessary for women and children for crime prevention of urban mixed-use commercial facilities. 3) Crime prevention planning is needed in urban mixed-use commercial facilities of the various isolation space. 4) Crime prevention through environmental planning is needed for facilities of after business hours. 5) Various security alarm system considering the characteristics of the space is needed for crime prevention. 6) Community program is necessary in order to increase the utilization of external public space. 7) A sign is necessary to prevent a criminal act in urban mixed-use commercial facilities. 8) The connection of commercial facilities and activity inducing factors is needed.

• Journal of the Korea Computer Industry Society
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• v.2 no.12
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• pp.1505-1516
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• 2001

The goal of Medical multimedia server is to develop computer hardware and software which would enable electronic access, storage, transmission, and display of patient data and images. Since the current network only provides so called "best-effort" services, it is impossible to satisfy QoS guarantee that is required for real time application services for emergency room, operating room etc. Accordingly, world-wide research is being made for a variety of services to provide QoS. he goal of DiffServ is to offer scalable differentiated service in Internet which are made possible by traffic classification and conditioning only performed at an edge(or a boundary) node. In case DiffServ was deployed in the Medical multimedia network, it is difficult to estimate how the QoS mechanism would affect totally the network performance. Therefore, we need to verify by simulation the design of algorithm which provide a variety of differentiated services. In QoS for Medical multimedia network, a simulator is designed and implemented using OPNET to investigate the performance of DiffServ QoS support mechanism. The developed DiffServ simulator may generate packets according to random, and bursty traffic models in order to incorporate diverse traffic conditions in the Medical multimedia network environment. Based on our simulation results, we confirmed that service differentiation is possible by using the EF(Expedited Forwarding) class in DiffServ networks.

• Korean Institute of Interior Design Journal
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• v.24 no.4
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• pp.33-42
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• 2015

A variety of attempts for trends to overcome the limits of the uniform styles and a fixed dichotomous structure and thoughts, have been made. This research aims to apply and analyze the application of concepts of the liminal space of contemporary architecture based on the destructive inclination of post-structuralism and the theories of philosophers. Space of the past was recognized for a long time focused on functions and styles that support the building. In modern and contemporary spaces, however, the boundary of contemporary space has been blurred with the mingling of cultural phenomenon. In other words, new architectural approaches of expression have been attempted such as structure, styles and materials, in combination of diversified concepts. And, the concept of liminal space is useful to identify the multi-layered and fluid characteristics. This study examines various characteristics of expression on the liminal space characteristics of comtemporary architecture tbased on Herzog and de Meuron's architecture. The result will help us understand the expression and characteristics of the liminal space that belongs nowhere among their architectural spaces. The analysis of the ases of Herzog and de Meuron will play a crucial role in developing new possibilities of modern space and contemporary space of the future.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.6
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• pp.162-167
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• 2006

The urban stream includes the channel and sandbars. The sandbar plays a key role in the riparian ecosystem. For birds and insects the sandbar offers a small strip of habitat and fish and other fauna feed in the boundary of sandbar where eddies occur. So, it is important habitat and source for the flow of energy, matter and organisms through the landscape and act as ecotone between the terrestrial and stream corridors. However, the sandbar changes continuously by the natural process. Thus, it is necessary to measure the shape and area of the sandbar accurately for the efficient urban stream management for the amenity of urban residents and stream protection. The study site is Yangjae Stream where the first natural-style urban stream restoration projected was impelemented by the support of Ministry of Education in Korea. The measurement was taken by the beacon Differential Global Positioning System (DGPS) and the data were stored and analyzed using ArcView Geographic Information System (GIS) program. Therefore, the purpose of this study is to measure the change of sandbars in the urban stream after concentrated stormwater during summer.

• Journal of the Korean Operations Research and Management Science Society
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• v.22 no.3
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• pp.37-58
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• 1997

An AI approach with tabu search is designed to solve multi-level knapsack problems. The approach performs intelligent actions with memories of historic data and learning effect. These action are developed ont only by observing the attributes of the optimal solution, the solution space, and its corresponding path to the optimal, but also by applying human intelligence, experience, and intuition with respect to the search strategies. The approach intensifies, or diversifies the search process appropriately in time and space. In order to create a good neighborhood structure, this approach uses two powerful choice rules that emphasize the impact of candidate variables on the current solution with respect to their profit contribution. "Pseudo moves", similar to "aspirations", support these choice rules during the evaluation process. For the purpose of visiting as many relevant points as possible, strategic oscillation between feasible and infeasible solutions around the boundary is applied. To avoid redundant moves, short-term (tabu-lists), intemediate-term (cycle-detection), and long-term (recording frequency and significant solutions for diversfication) memories are used. Test results show that among the 45 generated problems (these problems pose significant or insurmountable challenges to exact methods) the approach produces the optimal solutions in 39 cases.lutions in 39 cases.

• Environmental Engineering Research
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• v.22 no.4
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• pp.377-383
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• 2017

A tube-type ceramic membrane for microfiltration was developed, and the membrane module comprised of three membranes was also applied to biological carbon and nitrogen removal processes for post-treatment. Manufacturing the microfiltration membrane was successful with the structure and boundary of the coated and support layers within the membrane module clearly observable. Total kjeldahl nitrogen removal from effluent was additionally achieved through the elimination of solids containing organic nitrogen by use of the ceramic membrane module. Removal of suspended solids and colloidal substances were noticeably improved after membrane filtration, and the filtration function of the ceramic membrane could also easily be recovered by physical cleaning. By using the ceramic membrane module, the system showed average removals of organics, nitrogen, and solids up to 98%, 80% and 99.9%, respectively. Thus, this microfiltration system appears to be an alternative and flexible option for existing biological nutrient removal processes suffering from poor settling performance due to the use of a clarifier.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.414-417
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• 1997

This paper presents vessel contour for extracting features and segmentating narrow blood vessels down to a diameter of two pixels in digital subtraction angiographic image. We present a new tracking algorithm for contour, mainly blood vessels in DSA image, and extracting properties such as their intensities, diameters, and center lines by exploiting spatial continuity. The proposed algorithm comes to detect blood vessel's boundary using difference edge detector one of homogeneity operator and find a next centerline position by direction vector of edge information. This algorithm enhanced variation of vessel's diameter compared to Sun's tracking algorithm and lessoned to compute as direction vector decide adaptively entire vessel's direction field. The processed images are intended to support radiologists in diagnosis, radiation therapy planning, and surgical planning. The algorithm should be useful for automating angiographic analyses of blood vessels.

• Journal of Welding and Joining
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• v.33 no.3
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• pp.54-61
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• 2015

In this study, effect of laser power on hardness and microstructure of SKD61 Hot Die steel of which surface was melted and hardened with Yb:YAG disk laser was investigated. Beam speed was fixed at 70 mm/sec and distance between them was 0.8 mm about Laser surface melting. The only thing that was changed laser power. Laser powers were 2.0, 2.4 and 2.8 kW. No defect was found under all conditions. As the laser power increased, the penetration depth were deepened and the bead width was also widened. There was no hardness deviation of fusion zone at same laser power and it was higher than that of heat affected zone. In addition, the more laser power increased, the more hardness in fusion zone decreased. Fusion zone was macroscopically dendrite structure. However, core matric in dendrite was lath martensite of 100 nm size. There were $M_{23}C_6$ of 500 nm and the VC and $Mo_2C$ of a nano meters on boundary of dendrite.

• Speech Sciences
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• v.10 no.2
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• pp.319-338
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• 2003

The aim of this paper is to examine the sentence final tonal patterns of English wh-questions through phonetic experiments, based on Intonational Phonology, and to explain the meaning of the final phrase tones of English wh-questions. Pierrehumbert and Hirschberg (1990) suggested that it is pitch accents rather than boundary tones which play a crucial role in the meaning of a sentence, and that most of the general questions have H-H% tonal patterns in the sentence final. However, they could not explain why wh-questions had final falling tonal patterns (L-L%). While Bartels (1999) suggested that L phrase tone has the meaning of 'ASSERTION' and it could be applied to the explanation of the meaning of wh-questions' final tonal patterns. However, her suggestions are only theoretical explanation without any experimental support. In this paper, based on Bartels (1999), the data was classified into the following three classes: 1) echo wh-questions, 2) reference questions, and 3) common wh-questions. Using this data, a production test by three English native speakers was conducted. The results show that reference questions and common wh-questions have L phrase tones in the sentence final at a high rate, and echo wh-questions have H phrase tones in the sentence final at a high rate.