• 대한의용생체공학회:의공학회지
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• 제38권6호
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• pp.291-294
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• 2017

It is known that laptop computer stand is helpful to maintain the good posture while using laptop computer on the desk. But the quantitative validation of its effect has not been reported. Using the wearable neck posture tracker, the forward flexion angle of the neck can be measured in daily life. In this study, the forward flexion angles of the neck while using the laptop computer with and without laptop computer stand were compared. From the posture data of 10 subjects for 6 hours, the average of the forward flexion angle was 0.9 degree with laptop computer stand and 16.3 degree without laptop computer stand. As the conclusion, laptop computer stand can decrease the forward flexion angle which is known as forward head posture while using the laptop computer on the desk.

• Journal of Power Electronics
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• 제13권1호
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• pp.31-39
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• 2013

The conventional non-isolated boost converter has some drawbacks such as poor dynamic performance and a discontinuous output current, which make it unsuitable for battery charging applications. In spite of its compactness and lightness, it is not preferred as a charger of portable electronic devices. In this paper, a non-isolated boost converter topology for Li-ion batteries suitable for fuel cell powered laptop computers is proposed and analyzed. The proposed converter has an additional inductor at the output to make a continuous output current. This feature makes it suitable for charger applications by eliminating the disadvantages of the conventional non-isolated boost converter mentioned above. A prototype of the proposed converter is built for the Li-ion battery charger of a laptop computer to prove the validity and advantages of the proposed topology.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2012년도 전력전자학술대회 논문집
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• pp.177-178
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• 2012

In spite of its compactness and lightness, conventioan boost converter is not preferred for the charge applications. In this paper, a non-isolated boost converter topology for the Li-Ion battery suitable for fuel cell powered laptop computer is proposed and analyzed. The proposed converter has an additional inductor at the output to reduce the output ripple current and voltage. This feature makes it suitable for the charger application by eliminating the disadvantages of the conventional non-isolated boost converter mentioned above.

• Journal of electromagnetic engineering and science
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• 제17권3호
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• pp.126-132
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• 2017

In this study, we designed, measured, and analyzed a rearranged L-shape magnetic resonance coupling wireless power transfer (MR-WPT) system for practical applications with laptops. The typical four resonator MR-WPT (Tx part: source loop and Tx coil; Rx part: Rx coil and load loop) is difficult to apply to small-sized stationary and mobile applications, such as laptop computers, tablet-PCs, and smartphones, owing to the large volume of the Rx part and the spatial restrictions of the Tx and Rx coils. Therefore, an L-shape structure, which is the orthogonal arrangement of the Tx and Rx parts, is proposed for indoor environment applications, such as at an L-shaped wall or desk. The relatively large Tx part and Rx coil can be installed in the wall and the desk, respectively, while the load loop is embedded in the small stationary or mobile devices. The transfer efficiency (TE) of the proposed system was measured according to the transfer distance (TD) and the misaligned locations of the load loop. In addition, we measured the TE in the active/non-active state and monitor-open/closed state of the laptop computer. The overall highest TE of the L-shape MR-WPT was 61.43% at 45 cm TD, and the TE decreased to 27.9% in the active and monitor-open state of the laptop computer. The conductive ground plane has a much higher impact on the performance when compared to the impact of the active/non-active states. We verified the characteristics and practical benefits of the proposed L-shape MR-WPT compared to the typical MR-WPT for applications to L-shaped corners.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.490-495
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• 2001

This paper deals with an analysis and countermeasure for improving the shock performance of laptop computers. The shock analysis is carried out by using the commercial program of LS-DYNA3D. Also the analysis is verified by the measurements from modal tests and shock tests. The available countermeasures are investigated theoretically and experimentally to find the effective methods of reducing the shock acceleration on hard disk driver during one side fall test. The hard disk drive is the most sensitive part in a laptop computer. This research shows the effects of the spring constant of rubber pad, the reinforcement of mechanical parts and the location of a hard disk driver, on the shock reduction.

• 한국콘텐츠학회논문지
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• 제9권6호
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• pp.134-144
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• 2009

본 연구는 노트북 구매에 대한 소비자들의 의도를 이해하기 위하여 연구되었다. 본 논문은 Ajzen(1991)의 계획된 행동이론(TPB : Theory of Planned Behavior)을 서로 다른 라이프스타일에 따라 군집화 된 소비자들의 노트북 구매에 대한 의도를 비교하는데 적용하였다. 먼저 요인분석과 군집분석을 실시하여 소비자들을 4개 특성 그룹으로 나눈 다음 4개 특성 그룹 각각의 태도, 주관적 규범, 지각된 행위통제와 행동의도를 비교, 분석하였다. 본 연구의 목적을 달성하기 위해 주변에 노트북 구매, 사용경험이 있는 참여자로 부터 240부의 표본을 표집 하였으며, 이중 불성실한 응답을 한 17부를 제외한 223부의 자료를 연구에서 사용하였다. 회수된 자료는 SPSS 15.0과 AMOS 7.0 프로그램을 이용하여 요인분석, K-Means분석, 상관관계분석, 교차분석, 구조방정식 모형분석을 통해 소비자들의 노트북 구매의도를 알아보았다.

• 기술혁신연구
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• 제14권2호
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• pp.29-48
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• 2006

This paper analyzes organizational behavior of an established firm when disruptive innovation, a change in product architecture, occurs on a previous product. For the analysis, the paper analyzes and compares the behavior of an established fm through product trajectories between NEC (an established firm) and Toshiba (a new entrance) in the Japanese laptop computers industry. An established firm that has developed and produced a previous product is difficult in adapting to a disruptive innovation due to accumulated immense knowledge through a previous product. By using regression model in the product trajectory analysis, the paper analyzes the behavior of established firms. Product trajectory means a pattern of product strategy shown in a series of products. Two facts found in the paper are as follows. First, though NEC was able to develop a laptop computer at the same time with Toshiba, it was restricted by the resources of a previous product in the early stage. Second, possibility of teaming trap in the adapting process was found. The paper found the risk that too much commitment in one evolution stage would prohibit the adapting behavior in the next evolution stage.

• Design & Manufacturing
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• 제10권3호
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• pp.39-45
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• 2016

The purpose of this study is to build effective cooling circuit design in injection mold to improve glass fiber reinforced laptop computer cover plastics' transcription and gloss. Moldflow Insight and Ansys CFD CAE program used to verify efficiency and the experiment mold is precision machined and brazing soldered to make three-dimension cooling channel. The temperature of mold in injection test are fixed to $80^{\circ}C$ and $160^{\circ}C$. The result of this experiment is the improved surface quality of plastics with 85% improvement of transcription in high temperature mold.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1944-1949
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• 1991

In coming years fuzzy control techniques will be increasingly applied to plants in such fields as industry and public works. For this reason, it is extremely important that a high-quality support tool for systems configuration be developed. In this paper we will describe a comprehensive, user-friendly design tool for configuration of fuzzy control systems, called FZtool, that runs on a compact and cost-effective laptop computer.

• 한국기계가공학회지
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• 제10권3호
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• pp.53-59
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• 2011

In this study, a two-phase closed loop cooling system is desinged and tested for a laptop computer using a FC-72. The cooling system is characterized by a parametric study which determines the effects of existence of a boiling enhancement microstructure, initial system pressure, volume fill ratio of coolant and inclination angle of condenser on the thermal performance of the closed loop. Experimental data show the optium condition when the volume ratio of working fluid is 70%, the pump flowing is 6ml/min, and the inclination angle of condenser is $0^{\circ}$. This research shows the maximum values which can dissipate 33W of chip power with a chip temperature maintained at $95^{\circ}C$.