• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.1430-1436
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• 2007

A principal components analysis (PCA) of the median head-related impulse responses (HRIRs) in the CIPIC HRTF database reveals that the individual HRIRs can be adequately reconstructed by a linear combination of 12 orthonormal basis functions. These basis functions can be used generally to model arbitrary HRIRs, which are not included in the process to obtain the basis functions. To clarify whether these basis functions can be used to model other set of arbitrary HRIRs, an numerical error analysis for modeling and a series of subjective listening tests were carried out using the measured and modeled HRIRs. The results showed that the set of individual HRIRs, which were measured in our lab using different measurement conditions, techniques, and source positions, can be well modeled with reasonable accuracy. Furthermore, all subjects reported not only the accurate vertical perception but also the front-back discrimination with the modeled HRIRs based on 12 basis functions. However, as less basis functions were used for HRIR modeling, the modeling accuracy and localization performance deteriorated.

• 한국통신학회논문지
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• 제36권11B호
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• pp.1285-1296
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• 2011

패킷분류는 라우터의 가장 기본적이면서도 중요한 기능 중의 하나이며, 실시간 전송을 요구하는 새로운 인터넷 응용 프로그램의 등장과 더불어 그 중요성이 더욱 커지고 있다. 패킷분류는 입력 패킷에 대하여 선속도로 이루어져야 하며, 여러 헤더 필드에 대해 다차원 검색을 수행해야 하기 때문에 라우터 설계의 어려운 문제 중에 하나이다. 고속의 패킷분류를 제공하기 위한 다양한 패킷분류 알고리즘이 제안되어 왔으며, 그 중 계층적 접근 방식을 사용한 알고리즘은 하나의 필드에 대하여 검색이 수행될 때마다 많은 검색 영역이 제거되기 때문에 효율적이다. 그러나 계층적 구조는 역추적이라는 문제를 내재하고 있으며, 이를 해결하기 위해 사용되는 셋-프루닝 트라이나그리드-오브-트라이는 지나치게 많은 노드 복사를 야기하거나, 선-계산이라는 복잡한 과정을 요구한다. 본 논문에서는 셋-프루닝 하위 트라이의 간단한 합병을 통하여 복사되는 노드의 개수를 줄일 수 있는 스마트 셋-프루닝 구조를 제안한다. 시뮬레이션 결과 제안된 구조는 셋-프루닝 트라이와 비교하여 복사되는 노드 수 및 룰 수가 2-8% 줄어듦을 확인하였다.

• 한국주거학회논문집
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• 제17권2호
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• pp.117-124
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• 2006

Korean urban traditional housing abandoned by the social apathy promptly disappearing form our sight, or ruining. It tells that the strategies we are using today are impossible to fulfill socio-economic needs of residents here. So it needed to find out the strategies which can change this place better to live in. Consolidating the street parking lots fer cars can be one of the important solutions to the area. By using cul-de-sac, after setting up small unit of communities, we will have chance to have a small public space, and at the same time it can help to set up our tradition of people's intimacy inside the community. Most people have their own cars, and the need of parking lots becomes more serious. So, a meeting place like public well in the past must replace parking lots. On the other hand, it is important to re-consolidate existing land to obtain appropriate land size for other uses. Today, the use of private space (house, private lots, etc..)and public space(streets, local offices) is very important. NIMBY (Not In My Back Yard) attitude should also be reconsidered. All these negative social aspects come from negative social relationship, thus we should consider them with care and deep understandings. The traditional housing of Korea should not be abandoned as slum, but this should be transformed in terms of the conservation since it is superior in its ecological and energy conservation aspect.

• 한국컴퓨터정보학회논문지
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• 제23권11호
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• pp.111-122
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• 2018

The purpose of this study was to investigate the bodice prototype method suitable for the upper body shape of old-old aged women using the 3D anthropometric data. And it was to provide the basic data for the upper body garments of old-old aged women. In the overall appearance evaluation, the B pattern was rated as 4.00, and it was evaluated as the most suitable for the bodice prototype of the old-old aged woman. The E pattern was rated lower than normal, and the L pattern and the S pattern were found to be inadequate for older female bodice prototypes. As a result of the measurement of the waist and bust air gap of bodice prototype, the air gap of the bust was not significantly different between the patterns. But the waist air gap showed the largest difference between the L pattern and the S pattern. As a result of evaluating the appearance, the amount of space in the state of 3D simulation, and the air gap, the pattern B appeared to be the most appropriate prototype for the old-old aged women's body shape. However, there is a tendency that the shoulder end point is biased toward the back, so it is necessary to set the inclination of the back shoulder line to be more gentle. Conversely, the front shoulder should be more inclined. In the case of the 3D simulation, the B pattern showed that the other parts generally fit well. In the case of the 3D simulation program used in this study, it was evaluated that it is suitable only for the normal body shape because it is impossible to set the isometric angle which is one of the characteristics of the older female body shape. A study on the bodice prototype suitable for the bent body shape should be carried out through experiments on the actual body shape of various elderly women. In order to cope with the increase of elderly people who are familiar with digital, I think it is necessary to develop an avatar that reflects the old female body shape.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제29권2호
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• pp.148-156
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• 2007

Purpose: The aim of this study is the changes of upper respiratory airway space in patients with mandibular prognathism after 2-jaw orthognathic surgery in patients with skeletal classs III malocclusion. Method: We measured the lines between selected upper airway landmarks on lateral cephalometric x-ray films of skeletal class III 64 persons who had not been operated yet, were 6 months after operation. The test subjects were divided into 3 groups according to maxillary movement, as follows; maxillary advancement (MA) group, maxillary posterior impaction (MPI) group, maxillary posterior impaction and superior repositioning (MPI+MSR) group. Result: In this study, nasopharyngeal airway space in MPI+MSR group was significantly increased after operation (p<0.05). Oropharygeal and hypopharyngeal airway space in MA group and MPI group were significantly decreased after operation (p<0.05). From hyoid bone to anterior mandible point distance in MA group and MPI group were significantly decreased after operation (p<0.05). Conclusion: Oropharygeal and hypopharyngeal airway space were influenced more by mandibular set-back than maxillary movement. Maxillary movement surgery as well as mandibular setback surgery should be taken into consideration in order to minimize symptoms related to obstructive sleep apnea syndrome after operation.

• Advances in Computational Design
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• 제2권3호
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• pp.195-210
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• 2017

Simultaneous optimization of trusses which concurrently takes into account design variables related to the size, shape and topology of the structure is recognized as highly complex optimization problems. In this class of optimization problems, it is possible to encounter several unstable mechanisms throughout the solution process. However, to obtain a feasible solution, these unstable mechanisms somehow should be rejected from the set of candidate solutions. This study proposes triangular unit based method (TUBM) instead of ground structure method, which is conventionally used in the topology optimization, to decrease the complexity of search space of simultaneous optimization of the planar truss structures. TUBM considers stability of the triangular units for 2 dimensional truss systems. In addition, integrated particle swarm optimizer (iPSO) strengthened with robust technique so called improved fly-back mechanism is employed as the optimizer tool to obtain the solution for these class of problems. The results obtained in this study show the applicability and efficiency of the TUBM combined with iPSO for the simultaneous optimization of planar truss structures.

• 기술사
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• 제43권5호
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• pp.43-47
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• 2010

The epoch-making event of history called "JE JU 4.3" took place in JE JU beautiful island on liberation political situation in 1948. The cruelties of this event were reported awful life loss over 30,000, cruel slaughter by government, scorched villages in mountain area, silence exaction and disadvantage of implication for long time over 40 years. But, the real features are in still a fog.. Recently, the searching movement has arised owing to democracy atmosphere and literature works with "JE JU4.3" materials were published from 1988 and the government announced official apologies in 2003. The novel "The Sun-set on Halla Mt", one of those works, is accessible to real history due to its time/space back ground and the real name of persons who were related with this event. It is important for readers to consider the difference between real history and fiction story. Because a historical novel should be evaluated by writer's theme rather than history character.

• Journal of Positioning, Navigation, and Timing
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• 제10권2호
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• pp.113-120
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• 2021

The Distance Measuring Equipment (DME) is a ground-based aircraft navigation system and is considered as an infrastructure that ensures resilient aircraft navigation capability during the event of a Global Navigation Satellite System (GNSS) outage. The main problem of DME as a GNSS back up is a poor positioning accuracy that often reaches over 100 m. In this paper, a novel approach of applying deep reinforcement learning to a DME pulse design is introduced to improve the DME distance measuring accuracy. This method is designed to develop multipath-resistant DME pulses that comply with current DME specifications. In the research, a Markov Decision Process (MDP) for DME pulse design is set using pulse shape requirements and a timing error. Based on the designed MDP, we created an Environment called PulseEnv, which allows the agent representing a DME pulse shape to explore continuous space using the Soft Actor Critical (SAC) reinforcement learning algorithm.

• Journal of Computing Science and Engineering
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• 제10권1호
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• pp.32-38
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• 2016

Navigating a large 3D virtual environment using a generic haptic device can be challenging since the haptic device is usually bounded by its own physical workspace. On the other hand, mouse interaction easily handles the situation with a clutching mechanism-simply lifting the mouse and repositioning its location in the physical space. Since the haptic device is used for both input and output at the same time, in many cases, its freedom needs to be limited in order to accommodate such a situation. In this paper, we propose a new mechanism called Z-Clutching for 3D navigation of a virtual environment by using only the haptic device without any interruption or sacrifice in the given degrees of freedom of the device's handle. We define the clutching state which is set by pulling the haptic handle back into space. It acts similarly to lifting the mouse off the desk. In this way, the user naturally feels the haptic feedback based on the depth (z-direction), while manipulating the haptic device and moving the view as desired. We conducted a user study to evaluate the proposed interaction technique, and the results are promising in terms of the usefulness of the proposed mechanism.

• 항공우주정책ㆍ법학회지
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• 제9권
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• pp.277-298
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• 1997

Air transportation industry was established on a basis of liability limitation from the outset. Many treaties, however, had to be drafted since 1960' s to meet the need of the Unites States, who argued full compensation without limitation like other torts cases, but most of them were in vain. The Japanese Initiative in 1992, though being aimed to lower a level of compensation in air crash cases to that of other transportation accidents, showed a way to the U.S. how to solve the issue. Instead of obtaining an multilateral agreement through ICAO, the U.S. persuaded IATA to organize intercarrier consensus for voluntary waive the limitation. IATA succeeded in adopting Intercarrier Liability Agreement in 1995, in which carriers agreed not to use Warsaw limitation and accepted strict liability up to 100,000SDRs. Through a series of negotiation to implement the Intercarrier agreement, US DOT tried to insert a domicile standard provision to the agreement which enable US victims to be compensated according to the law of the U.S. regardless of the situation. IATA opposed the intent aggressively. The U.S. set back to the starting point remaining issues for further discussion. The liability limitation under the Warsaw system is being collapsed. It is the result of a simple logic; liability limitation cannot be maintained without appropriate compensation.