• 한국멀티미디어학회논문지
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• 제8권3호
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• pp.362-371
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• 2005

본 논문은 장애물에 강한 수신성능과 이동수신에 강점을 가지고 있는 직교 주파수분할 다중화 방식을 기초로 한 유럽 지상파 디지털 방송의 텔레비전 수신기 개발에 관한 것이다. 본 연구에서는 유럽 지상파 디지털 텔레비전 시스템을 위한 향상된 직교 주파수분할 다중화 방식의 수신기 개발을 목표로 하여, 향후 기능 확장성을 고려하여 유럽 지상파 디지털 방송의 텔레비전 수신기 시스템을 설계하고 개발하였다. 본 수신 시스템을 개발한 후 현재 시판되고 있는 기존에 개발된 다른 3가지 모델과 함께 수신 모뎀 칩의 성능을 하드웨어로 비교하여, 본 시스템의 우수성 여부를 최소 반송파 대 잡음비 및 가시청 한계 비트 오율을 통하여 실험하였다 또한 디지털 텔레비전을 시청하는 사용자를 위하여 그래픽 사용자 인터페이스 및 전자 프로그램 가이드를 개발하였다.

• 한국실내디자인학회논문집
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• 제18권2호
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• pp.80-92
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• 2009

Natural history museums preserve and manage the creatures living in each country, so they play unique roles for bio-diversity, and in fact, their roles are really instrumental for the collection, preservation, research, exhibition and education of creatures in the 21st century. Therefore, this research has the purpose to survey the status of our country's existing natural history museums, analyze their visual perception space structural characteristics, and ultimately utilize their characteristics as basic data in planning out and designing spaces of natural history museums to be established later on. As for the research scope, the research selected as research subjects 7 natural history museums that currently have composite set of open type and mixed type and have been accommodating comparatively active exhibitions since 2000 among 10 or so natural history museums in our country. Research method is that the research analyzed the exhibition spaces of 7 natural history museums by using depthmap program which can analyze space with visual graph analysis function, and analyzed the visibility among unit areas by each natural history museum integration and exhibition contents composition. In such analysis method, the research was able to quantitatively analyze the visual characteristics of exhibition space that induces and adjusts the motion of audience. Visual perception quantitative analysis as in this research will enhance exhibition design by considering the correlation between audience and exhibited items when planning out natural history museums space to be established later on.

• 한국산학기술학회논문지
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• 제10권10호
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• pp.2985-2989
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• 2009

본 논문에서는 학습집중력을 향상시킬 수 있는 시트를 제작하였다. 학습집중력의 향상을 입증하기위하여 인체 내에 존재하고 있는 조영제를 이용하여 공간적 시간적 해상도가 뛰어나고 비침습적으로 뇌기능을 측정할 수 있는 기능적 자기공명영상을 획득하여 분석을 한 결과 기억작용과 관련 있는 전두엽 부근의 뇌혈류량의 활성화를 확인할 수 있었고 뇌파 측정 분석 결과 절대알파파와 절대베타파의 비율에서 유의할 만한 변화를 확인하였다. 기능적 자기공명영상은 뇌의 생리기능적 역할을 규명, 의학적으로 수술 전후 장애를 방지하고 예방하는데 활용되고 있으며 뇌신경망의 가시화로 학습집중력 향상 시트등과 같이 뇌와 관련된 제품을 개발하는데 많은 연구가 이루어질 것이다.

• 한국멀티미디어학회논문지
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• 제6권3호
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• pp.508-517
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• 2003

본 논문에서는 쌍직교 웨이브릿 영역에서 워터마크를 삽입할 수 있는 연속 부대역 양자화 및 스토케스틱 다해상도 특성을 갖는 지각 모델을 제안한다. 적응 워터마킹 알고리즘을 갖는 지각모델은 보다 강인한 워터마크 은닉을 위한 방법으로 연속 부대역 양자화(successive subband quantization: SSQ)에 의해서 텍스쳐 및 에지 영역에 삽입한다. 워터마크 삽입은 국부 영상 특성을 갖는 NVF(noise visibility function)함수에 의해 계산된다. 이 방법은 워터마크가 노이즈 특성을 갖기 때문에 영상의 통계적 특성에 기초한 비정상상태(non-stationary state) 가우스 모델과 정상상태(stationary state) 일반화 가우스(generalized Gaussian: GG)모델을 이용한다. 정상상태 GG모델의 삽입은 다해상도 내의 각 부대역별 분산과 형상계수(shape parameter)를 사용한다. 형상계수를 추정하기 위하여 모멘트 정합 방법을 사용한다. 비정상상태 가우스 모델은 각 부대역의 국부 평균 및 분산을 이용한다. 실험결과 우수한 비가시성과 강인성을 확인하였으며, 공격에 대한 실험으로 Stirmark 3.1 benchmark test를 수행하였다.

• 과학기술학연구
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• 제13권1호
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• pp.1-39
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• 2013

과학적 실행에서 기술과학자들의 협력은 어떻게 발생하는가? 과학의 주변부에 위치지어진(situated) 한국의 기술과학자들은 실험실에서 맥락화된 형태로 협력연구를 하게 된다. 이러한 협력은 실험실의 블랙박스를 열기 전에는 보이지 않다가, 논쟁 토론 공동연구 하청 등의 특정한 상황 하에서는 가시성을 획득하여 화이트박스가 된다. 그리고 해당 상황이 종료되면 다시 블랙박스화가 이루어져 기술과학자 본인들과 외부의 관찰자 모두에게 비가시적이 된다. 블랙박스가 열리고 닫히는 이 과정은 실험실 공간에서 순간순간 서로 겹쳐진 형태로 무수히 발생하여 매 단계 이를 구분하는 것이 어려울 정도이며, 실험실에서 과학적 실행의 결과로 정돈된 불변의 동체가 생성되는 과정을 블랙박스화의 과정으로 본 크노르-세티나나 린치, 라투어-울가 등의 분석은 지나치게 단층적이고(single-layered) 실제 상황을 충분히 잘 묘사하지 못한 측면이 있다. 실험실에서의 협력은 가시성과 비가시성을 동시에 갖는 비/가시적 특성을 지니며, 이는 블랙박스와 화이트박스를 구분하는 것이 불가능한 회색상자에 가깝기 때문이다. 또 이러한 기제의 작동 공간인 실험실은 푸코가 주장한 헤테로토피아(heterotopia)로서 기능한다.

• 건축역사연구
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• 제6권3호
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• pp.129-143
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• 1997

The perspective representation and its effect that appeared in the tombs and mural paintings of koguryo are summarized as follows: First, The inside structure of the tombs is likely to show the deepness effect, placing each function in the front and both sides centering around the mane pillars and creating the boundaries and the spaces that have various visibility between the inside and outside spaces of the structure just like a traditional Korean house shows. In addition, The deepness effect is emphasized by suggesting that the spaces are countinued with a storage attached behind the main house or by forming the level and deployment in a narrow space like the scene that a large array is looked out from the main house. Second, The deepness effect is expressed by making the form of ceiling turn to a vertical space of an ascending image, constructing it just as the lotus lamp ceiling of a wooden architecture or drawing it just like the imaginary heavenly world with the sun the moon and mythical fairies and animals spread in it. Thried, The perspective effect is disclosed by drawing the mural pictures in an equally set bird's-eye view without regard to the disfance proportion according to the conceptual visualization which is not a visual penetration, adopting the multiple view points and moving view points that are moving around as an important manner of seeing. Fourth, The deepness effect is emphasized through the scene of changing spaces when they are looked out far or looked into depending on a viewpoint of the daily life by forming the fromes of paintings that we made up with actual pillars, Du Gong, crossbeams or that are painted in most tombs. Fifth, The rich spatial senses are reflected by originating the characters of the three directions, level, deployment and ascending. An example which can support the conclusion of this study can be given here. that is, the construction ground plan of a dwelling house of a nobleman at the end of Koguryo as a remain which was excavated at Dongdae Ja in Jip An.

• 패션비즈니스
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• 제17권6호
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• pp.98-110
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• 2013

This research is to study the functional color arrangement of work clothes based on the color chroma value arrangement, which could affect the safety of workers at the site of the mechanical industry. For the study, 5PB hue, indicating a high satisfaction level with proper colors at the site of the mechanical industry, were selected from previous research for 6 types of CAD simulation on a 2-color chroma value arrangement. To analyze the color data of each color arrangement after applying the color chroma value arrangement as well as to figure out the level of recognition on the color arrangement, an analytical result, which was based on the NCS color system, was evaluated. Furthermore, the survey study on items regarding the safety of the relevant work site for the simulated result was executed. As a result of the evaluation, the color arrangements which include high color chroma value indicated a high satisfactory level in all items under the visibility criteria for the safety of workers, propriety as a color arrangement of work clothes, and safety from the perspective of work site management. In particular, the color arrangement mixture between high color chroma obtained the highest satisfactory evaluation, indicating that the color arrangement of high color chroma is essential in the color arrangement of work clothes for the establishment of safety by adjusting the color chroma value. Yet, in order to figure out the independent function of the color chroma value, other factors are restricted in this study. Thus, it is not proper to apply the result of this study only at the actual work site. Therefore, a follow-up research centered on the tones of all three types is proposed, from which we can expect, a suggestion of the applicable color guideline for the industrial site.

• 산업경영시스템학회지
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• 제41권1호
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• pp.39-49
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• 2018

In the satellite operation phase, a ground station should continuously monitor the status of the satellite and sends out a tasking order, and a satellite should transmit data acquired in the space to the Earth. Therefore, the communication between the satellites and the ground stations is essential. However, a satellite and a ground station located in a specific region on Earth can be connected for a limited time because the satellite is continuously orbiting the Earth, and the communication between satellites and ground stations is only possible on a one-to-one basis. That is, one satellite can not communicate with plural ground stations, and one ground station can communicate with plural satellites concurrently. For such reasons, the efficiency of the communication schedule directly affects the utilization of the satellites. Thus, in this research, considering aforementioned unique situations of spacial communication, the mixed integer programming (MIP) model for the optimal communication planning between multiple satellites and multiple ground stations (MS-MG) is proposed. Furthermore, some numerical experiments are performed to verify and validate the mathematical model. The practical example for them is constructed based on the information of existing satellites and ground stations. The communicable time slots between them were obtained by STK (System Tool Kit), which is a well known professional software for space flight simulation. In the MIP model for the MS-MG problems, the objective function is also considered the minimization of communication cost, and ILOG CPLEX software searches the optimal schedule. Furthermore, it is confirmed that this study can be applied to the location selection of the ground stations.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.62-67
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• 2004

Many ships in voyage experience weight and buoyancy distribution change by various reasons such as change of sea water density and waves, weather condition, and consumption of fuel, provisions, etc . The weight and buoyancy distribution change can bring the ships out of allowable trim, heeling angle. In these case, the ships should adjust trim and heeling angle by shifting of liquid cargo or ballasting, deballasting of ballast tanks for recovery of initial state or for a stable voyage. But, if the adjustment is performed incorrectly, ship's safety such as longitudinal strength, intact stability, propeller immersion, wide visibility, minimum forward draft cannot be secured correctly. So it is required that the adjustment of trim and heeling angle should be planned not by human operators but by optimization computer algorithm. To make an optimized plan to adjust trim and heeling angle guaranteeing the ship's safety and quickness of process, Uk! combined mechanical analysis and optimization algorithm. The candidate algorithms for the study were heuristic algorithm, meta-heuristic algorithm and uninformed searching algorithm. These are widely used in various kinds of optimization problems. Among them, heuristic algorithm $A^\ast$ was chosen for its optimality. The $A^\ast$ algorithm is then applied for the study. Three core elements of $A^\ast$ Algorithm consists of node, operator, evaluation function were modified and redefined. And we analyzed the $A^\ast$ algorithm by considering cooperation with loading instrument installed in most ships. Finally, the algorithm has been applied to tanker ship's various conditions such as Normal Ballast Condition, Homo Design Condition, Alternate Loading Condition, Also the test results are compared and discussed to confirm the efficiency and the usefulness of the methodology developed the system.

• Imaging Science in Dentistry
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• 제47권3호
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• pp.199-207
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• 2017

Purpose: Evaluation of alveolar bone is important in the diagnosis of dental diseases. The periodontal ligament space is difficult to clearly depict in cone-beam computed tomography images because the reconstruction filter conditions during image processing cause image blurring, resulting in decreased spatial resolution. We examined different reconstruction filters to assess their ability to improve spatial resolution and allow for a clearer visualization of the periodontal ligament space. Materials and Methods: Cone-beam computed tomography projections of 2 skull phantoms were reconstructed using 6 reconstruction conditions and then compared using the Thurstone paired comparison method. Physical evaluations, including the modulation transfer function and the Wiener spectrum, as well as an assessment of space visibility, were undertaken using experimental phantoms. Results: Image reconstruction using a modified Shepp-Logan filter resulted in better sensory, physical, and quantitative evaluations. The reconstruction conditions substantially improved the spatial resolution and visualization of the periodontal ligament space. The difference in sensitivity was obtained by altering the reconstruction filter. Conclusion: Modifying the characteristics of a reconstruction filter can generate significant improvement in assessments of the periodontal ligament space. A high-frequency enhancement filter improves the visualization of thin structures and will be useful when accurate assessment of the periodontal ligament space is necessary.