• 설비공학논문집
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• 제14권11호
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• pp.880-889
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• 2002

The purpose of the present study is to examine the factors affecting the heat transfer limitations of screen mesh heat pipe for electronic cooling by theoretical analysis. Diameter of pipe was 6 mm, and mesh numbers are 50, 100, 150, 200 and 250 and water was selected as a working fluid. According to the change of mesh number, wick layer, inclination and saturation temperature, capillary pressure, pumping pressure, liquid friction coefficient in wick, vapor friction coefficient, capillary limitation, entrainment limitation, sonic limitation and boiling limitation we analyzed by theoretical design method of a heat pipe. As some results, the capillary limitation in small diameter of heat pipe is largely affected by mesh number and wick layer.

• 한국멀티미디어학회논문지
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• 제12권2호
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• pp.272-280
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• 2009

모바일 기술의 발전으로 오프라인 컨텐츠가 아닌 온라인 매체로 다양한 영상 컨텐츠를 제공받는 수요층이 늘어나고 있다. 그러나 모바일 단말기의 작은 화면에 맞게 수작업으로 편집/수정하기 위해서는 비용과 노력이 많이 드는 단점이 있다. 따라서 본 논문에서는 영상 컨텐츠 가운데 가장 다양한 형태를 지닌 인쇄 만화를 모바일 단말기 환경에 맞게 자동 변환하는 Automatic Comics Conversion(ACC) 시스템을 제안한다. 모바일 단말기 화면에 적합한 형태로 기존 오프라인 만화책 각 한 면의 프레임으로 분할하기 위해 다층신경망(MLP: Multi-Layer Perceptorn)을 이용하였으며, 각 프레임은 영상의 의미 구조 (Semantic Structure)의 손실을 최소화하여 적합한 크기로 분할된 영상들을 자동 변환하여 제공한다. 또한 동적인 만화 영상을 애니메이션으로 제공하기 위하여 텍스처 분석 연구를 더 했다. 이에 본 연구는 만화뿐만 아니라 프레임 단위로 되어있는 사진, 웹사이트, 다양한 영상 등을 언제 어디서나 제공받을 수 있도록 모바일 단말기에 제공함으로써 효율성을 검증한다. 또한 오프라인의 정지 영상을 분할된 영상 프레임 정보를 통해 움직이는 영상으로 제공할 수도 있다.

• 한국농촌건축학회논문집
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• 제21권3호
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• pp.17-24
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• 2019

This study aimed to develop a mobile separating and sorting device for discharge sites to separate and sort mixed construction waste generated in small and medium scale in small provincial cities into inorganic materials and combustible materials. The study results can be summarized as follows: 1) As a result of analyzing the existing domestic technology for the separating and sorting mixed construction waste, a device sorting the waste by fusing the vibration screen, disc screen, air blowing methods and the separating and sorting the combustible waste is applied in Korea. 2) In foreign countries, the air blowing, screen, gravity sorters are used for separating and sorting combustible waste in the same way as in Korea. Especially German T Company suggests a construction waste separating and sorting system using an optical sorter. 3) As for the test device for separating and sorting mixed construction waste to be buried in landfill, the processing capacity was set as 16 tons per day. 4) For separating and sorting inorganic materials by granularity, this study set a trommel with two types of diameter as a basic. To operate the mobile all-in-one system, the device is designed to locate a conveyor, a combustible waste conveying device, inside of the trommel. 5) The device is designed in a mobile mode under the concept of primary separating and sorting device, and it can be transported using a 2.5-ton truck minimum. The diameter and length of the trommel are designed to be within 1500mm and 3000mm, respectively. In a further study, an optimized separating and sorting technology is planned to be presented through an experimental study for processing efficiency analysis at the mixed construction waste site by manufacturing the pilot experiment facility reflecting the design elements in the result of this study.

• 산업공학
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• 제22권4호
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• pp.347-358
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• 2009

Panning tasks caused by both a small screen and the lower resolution of handheld devices are known to decrease the usability of a mobile internet service. To solve this problem, we proposed FTND, an improved version of Tap-N-Drag widely used in various mobile web browsers. 30 participants performed the panning tasks with FTND embedded in combinations of 2 panning directions of Push Background user interface and Push Viewpoint user interface and 5 panning ratios of 100% (a panning ratio of Tap- N-Drag), 300%, 500%, 700%, and 900%. The usability of FTND was assessed by an objective performance and a subjective preference. The objective performance was measured by a task completion time, the number of clicks, and the number of pixels. The subjective preference was measured by satisfaction, accuracy and ease of use. Push Viewpoint user interface at the panning ratios of 300%, 500%, and 700% proved to be the most efficient way for panning tasks with small handheld devices when performing the task by using the right hand thumb.

• 정보처리학회논문지B
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• 제9B권5호
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• pp.523-532
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• 2002

최근 들어 인터넷이 광범위하게 보급되고 무선 이동통신 기술이 눈부시게 발전하면서 무선 단말기를 통한 인터넷 상에서의 정보 검색이 시간과 장소에 구애받지 않고 가능하게 되었다. 하지만 무선 단말기를 통한 인터넷의 접근은 단말기 자체의 제한과 무선망의 제한으로 인해 기존 데스크 탑 컴퓨터의 유선 상에서 보다 웹 페이지 탐색에 많은 어려움을 가진다. 본 논문은 이러한 제약을 완화시키기 위해서 웹 페이지로부터 페이지 정보를 축소한 페이지 맵을 생성하여 웹 정보를 쉽게 검색할 수 있게 하는 페이지 재구성 시스템을 제안한다. 그리고 대표적인 웹 사이트에 대한 실험을 통해 제안한 시스템이 무선 단말기 상에서 빠른 웹 페이지 로딩 속도를 보장하며, 작은 스크린을 통해서도 효율적인 웹 탐색이 가능함을 보인다.

• 마이크로전자및패키징학회지
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• 제20권4호
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• pp.65-68
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• 2013

A novel bumping process using solder bump maker (SBM) is developed for fine-pitch flip chip bonding. It features maskless screen printing process. A selective solder bumping mechanism without the mask is based on the material design of SBM. Maskless screen printing process can implement easily a fine-pitch, low-cost, and lead-free solder-on-pad (SoP) technology. Its another advantage is ternary or quaternary lead-free SoP can be formed easily. The process includes two main steps: one is the thermally activated aggregation of solder powder on the metal pads on a substrate and the other is the reflow of the deposited powder on the pads. Only a small quantity of solder powder adjacent to the pads can join the first step, so a quite uniform SoP array on the substrate can be easily obtained regardless of the pad configurations. Through this process, an SoP array on an organic substrate with a pitch of 130 ${\mu}m$ is, successfully, formed.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 춘계학술대회 논문집
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• pp.280-281
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• 2009

Piezoelectric vibrators can be good replacements of electric motors to excite touch screen of a mobile device owing to small volume and low power consumption. One problem to be solved yet for real application is larger excitation force or moment than available currently. More efficient excitation by a piezoelectric vibrator could be achieved by operating at one of resonance frequencies of the system, which must also be as close as possible to frequency range where index finger is most sensitive and increasing transmission force or moment at that frequency. In this study, dynamic models are derived for the piezoelectric exciter and an adhesive viscoelastic layer, which connect the exciter to the screen. The adhesive layer is modeled as distributed stiffness by considering its geometric shape to relative to the piezoelectric exciter. Then, equations of motion for the piezoelectric exciter and the adhesive layer are derived using Hamilton's principle. Based on this model, dynamic characteristics of the exciter will be designed to maximize the force or moment transmitted onto the screen structure.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.342-345
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• 2002

As the size of chip components and module decreases, new patteming method for fine line and geometry is needed. So far, in LTCC(Low Temperature Cofired Ceramic) process, screen printing method has been used generally. But screen printing method has some disadvantages as follows. First, the geometry including line, vias, etc. smaller than $100{\mu}m$ can't be evaluated easily. Second, the patterned dimension is different from designed value, which makes distortion in charactersitics of not only chip components but also modules. Thick film lithography has advantages of thick film screen printing process, low cost and thin film process, fine line feasibility. Using this method, the line with $30{\mu}m$ width and the geometry with expected dimension can be evaluated. In this study, the fine line with $35{\mu}m$ line/space is formed and the embedded capacitor with very small tolerance is developed using thick film lithography.

• 한국통신학회논문지
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• 제40권2호
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• pp.363-365
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• 2015

최근 스마트폰의 보급 확대와 더불어 스마트폰이 컴퓨터의 업무를 대체하는 환경에서 스마트폰의 작은 화면을 대형 TV나 컴퓨터용 모니터로 확대 미러링(mirroring)하는 방법들이 연구되고 있다. 본 논문에서는 스마트폰이나 스마트기기의 표준 5핀(MHL지원) 출력을 HDMI 포트의 모니터로 연결하여 화면 미러링과 동시에 블루투스 통신과 USB 호스트 기능을 이용하여 마우스와 키보드를 효율적으로 제어하여 스마트폰을 컴퓨터처럼 사용할 수 있는 시스템을 구현하였다. 본 연구의 결과는 독(dock) 형태와 모니터 일체형 시스템으로 각각 구현하였다.

• 반도체디스플레이기술학회지
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• 제20권3호
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• pp.184-188
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• 2021

In general, digital signage is a next-generation smart media that provides various information and advertisement services to many people indoors or outdoors using the Internet. Recently, digital signage is rapidly spreading in such a small indoor environment, that is, in an area closely related to daily life, for example, inside an elevator. However, in this kind of indoor environment where the stay time of persons is extremely limited, it would be not easy for them to keep advertisements in the user memory for a long time. In the digital signage display installed in an indoor environment, it is possible to think about the possibility for a function such as expanding the screen to a user's smartphone, which is now widely spread, to contain, store, and use the transmitted content. In this paper, we propose a method to extend the display of digital signage contents to personal smart phones with interaction function in such a limited environment. In order to make the system operation, the proposed system was verified by confirming the result of dual screen implementation in a smart phone through the prototype implementation of a digital signage system in an embedded Linux environment.