• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1258-1265
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• 2013

The objective of this study is to investigate the association between touchpad &buttons locations in a laptop computer and EMG amplitude and median frequency in muscles related with wrist and shoulder. Based on previous studies it was shown how abductions in wrist and shoulder could cause musculoskeletal disorders in those body parts, on which research hypotheses were established. Touchpad &buttons positions consisted of bottom center(BC), bottom center with $45^{\circ}$ rotation counterclockwise(BCR), and bottom right(BR). 10 subjects performed the task that required only touchpad &buttons usage with their preferred hand and EMG amplitude and median frequency data were recorded during 5min and analyzed afterwards. Upper trapezius and flexor carpi ulnaris were selected as target muscles. The results showed that in flexor carpi ulnaris BC resulted in greater amplitude and less median frequency than BCR and BR, but there was no significant difference between BCR and BR. In upper trapezius BC and BCR induced higher amplitude and lower median frequency than BR, but the significant difference between BC and BCR was not observed. Those phenomena occurred since BC gave rise to both wrist and shoulder abduction, BCR caused only shoulder one, and BR did not lead to abductions in both wrist and shoulder.

• Journal of Korea Technology Innovation Society
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• v.8 no.1
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• pp.135-153
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• 2005

With an explosive growth of internet and a change of consumer's demand, Post PC is emerging as a substitute for the existing desktop computer and laptop computer. Post PC is a new computer which is portable with wireless networking, cheaper than the existing PCs and specialized in the specific function that consumers want. Furthermore, the shape and the ability of Post PC are dependent on its specific function. The rudimentary Post PCs such as PDA, web-pad and smart-phone are already usable. And in the future, owing to the progress of technologies, the heterogeneity of relate companies and the low entry barrier, various Post PCs will be developed. In this paper, we analyze consumers' willingness-to-pay for Post PC with the attributes such as the portability, the speed of CPU, the data input method (using key board, or notepad etc), the size of monitor and price. To estimating consumers' willingness-to-pay for the attributes of Post PC, we apply a contingent ranking method, which makes the respondents rank hypothetical Post the portability, the speed of CPU, the data input method (using key board, or notepad etc),the size of monitor and price. To estimating consumers' willingness-to-pay for the attributes of Post PC, we apply a contingent ranking method, which makes the respondents rank hypothetical Post PC alternatives featuring various combinations of attributes, to a survey data collected in Korea. Using the estimated willingness-to-pay, we predict the shape and the ability of future's Post PC and draw policy implications for the national and company level R&D strategies.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.3
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• pp.551-558
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• 2015

As more people use Wi-Fi and hotspot, unauthorized APs become one of big security problems in modern society. From the beginning of 2010, researchers study about unauthorized AP continually and contributed a lot of methods of detecting unauthorized AP that use wireless resources. Many researches about unauthorized AP detection use time-delay measurement (e.g., average or standard deviation) which is caused by additional wireless connection. In the most previous researches, however, the unauthorized APs consist of laptop and pulg-in Wi-Fi adaptor, and researchers did not concern about time-delay caused by software network sharing. In this paper, we show that existing unauthorized AP detection scheme that can not efficiently classify the high performance unauthorized AP.

• Journal of the Korea Society of Computer and Information
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• v.14 no.1
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• pp.107-115
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• 2009

The cryptological key which is used in WiMAX environment is used at regular intervals by mobile nodes (laptop computer, PDA, cell-phone) which is in the range of base station coverage. But it is very weak at local attack like man-in-the-middle when the mobile node is off the range of base station or enters into the range to communicate with base station because the communication section is activated wirelessly. This paper proposes a distribution key building protocol which can reuse security key used by nodes to reduce cryptological security attack danger and communication overhead which occurs when mobile node tries to communicate with base station. The proposed distribution key establishing protocol can reduce overhead which occurs between base station and mobile node through key reusing which occurs during the communication process and also, makes security better than IEEE 802.16 standard by creating shared key which is required for inter-certification through the random number which node itself creates.

• Journal of the Korean Society of Physical Medicine
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• v.18 no.2
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• pp.103-114
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• 2023

PURPOSE: This study compared the effects of computer-based and virtual reality-based cognitive rehabilitation programs on the cognitive function, upper limb function, activities of daily living, and their impact on the prefrontal cortex in convalescent stroke patients. METHODS: Ten recovering stroke patients were assessed for their cognitive function, upper limb function, and daily living activities using the Neurobehavioral Cognitive Status Examination, the Korean version of the Fugl-Meyer Assessment, and the Korean version of the Modified Barthel Index. The prefrontal cortex activity was measured with functional Near Infrared Spectroscopy. The virtual reality-based cognitive rehabilitation group utilized a program of daily living activities delivered via a laptop and Oculus Rift. The computer-based cognitive rehabilitation group performed various cognitive tasks on an all-in-one PC. Both groups underwent cognitive rehabilitation training for 30 minutes per day, three times a week, for six weeks, with identical conventional rehabilitation therapies in the hospital. RESULTS: Both programs positively impacted the cognitive and physical functions. On the other hand, the virtual reality-based cognitive rehabilitation program had a larger influence on improving the cognitive and physical functions of convalescing stroke patients. CONCLUSION: The virtual reality program suggests its potential to enhance cognitive and physical functions in convalescent stroke patients through increased engagement, focus, real-time feedback, and game elements, making it a promising rehabilitation approach.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.1
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• pp.16-24
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• 2009

This research aims to measure and analyze the dimensions of typical office chairs and desks sold in domestic market, and to suggest the modifications of national guidelines considering Korean peoples' body characteristics. The scope of this study was limited to the desktop type of computer jobs, excluding laptop environment. The dimensions of 24 different office chairs and 7 tables were measured, and their dimensions were analyzed against the Ministry of Labor (MOL) Notification and Korean Standards (KS). At the same time, the data from the Size Korea was also considered. As a result, the KS guidelines were overall fulfilled by the measured products, while the MOL Notification was not. It was found that the guidelines on the chair height, seat pan depth, lumber support height, and armrest height need to be modified. Some inconsistencies between the MOL Notification and KS were also found. It is suggested that the required dimensions specified by both guidelines should be unified.

• Herbal Formula Science
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• v.23 no.1
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• pp.121-131
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• 2015

Objectives : This study was conducted to investigate the membrane potential to apply Doksam-tang to a human heart failure model. Methods : The human heart model was built by Luo et al. CellML model, Priebe et al. CellML model, and a human heart mesh file. Doksam-tang gives channel the half maximal inhibitory concentration(IC ₅₀ ), half maximal effective concentration(EC ₅₀ ) values and compounds concentrations. These data load into the laptop with Ubuntu OS, and build the library with the data. Results : While results of the study with the heart failure model shows abnormal membrane potential from the normal heart model, the study with applying Doksam-tang to heart failure model shows restoring membrane potential that is similar to normal heart model. Conclusions : These results of the testings suggest that a conception of novel technique to investigate the effects of Korean herbal medicine.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.259-261
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• 2008

The electronic products such as laptop PC, cellular phone, robots and etc. need the DC power source. Recently, the secondary battery is frequently used as the portable DC power source and it needs forming process. In this paper, we proposed the bidirectional converter that the battery can be charged with high power factor and the discharged energy is regenerated into AC power source. In the charging mode, the converter acts as the boost rectifier. And the AC input current is controlled in phase with the AC input voltage. As a result, the power factor is improved nearly to unity. In the discharging mode, the DC power of battery wasted in resistor is regenerated to the AC bus line. Finally, the validity of the proposed bidirectional converter is verified by computer simulations and experimentation.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.37-44
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• 2006

본 연구는 모바일기기 사용자들의 특성을 알아보고자 사용자들의 모바일기기 휴대의도에 영향을 미치는 변수들을 기준으로 사용자들을 세분화 하였다. 선행문헌연구를 통해 휴대의도에 영향을 미치는 변수들로 유용성, 즐거움, 불안감과 사회적 영향인 주관적 규범, 가시성, 이미지, 자발성 등을 도출하였다. 자료수집을 위해 서울 및 수도권에 거주하고 휴대폰이나 노트북, PDA등을 소유한 대학생 및 대학원생과 직장인들을 대상으로 설문조사를 실시하였다. 휴대의도의 영향변수 분석결과 불안감과 주관적 규범이 휴대의도에 유의한 양의 영향을 미치는 것으로 검증되었다. 이를 기준변수로 군집분석을 통해 전체 표본을 네 집단으로 세분화 하였다. 세분화 결과 군집 1은 주관적 규범만이 영향을 미치는 집단으로 전체응답의 36.25%를 차지하고 있으며, 군집 2는 불안감만이 영향을 미치는 집단으로 전체 응답의 13.44%를 구성하는 것으로 나타났다. 군집 3은 불안감과 주관적 규범 모두 영향을 미치지 않는 집단으로서 전체 응답에서 19.06%를 차지하고 마지막으로 군집 4는 불안감과 주관적 규범 모두 영향을 미치는 집단으로 전체응답의 31.25%를 구성하는 것으로 나타났다.

• Journal of Mechanical Science and Technology
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• v.15 no.12
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• pp.1775-1783
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• 2001

For two decades, there has been an active research to enhance the performances of Particle Image Velocimetry (PIV) systems. However, the resulting systems are somewhat very costly, cumbersome and delicate. In this paper, we address the design and some first experimental results of a PIV system belonging to the opposite paradigm. The Miniature PIV or MPIV system feature relatively modest performances, but is considerably smaller (out MPIV could hold in dia. 40 mm$\times$120 mm), cheaper (out MPIV total cost is less than $500) and easy to handle. Potential applications include industrial velocity sensors. The proposed MPIV system uses a one-chip-only CMOS camera with digital output. Only two other chips are needed, one for a buffer memory and one for an interfacing logic that controls the system. Images are transferred to a personal computer (PC or laptop) via its standard parallel port. No extra hardware is required (in particular, no frame grabber board is needed). In our first MPIV prototype presented in this paper, the strobe lighting is generated by a cheap 5 mW laser pointer diode. Experimental results are presented and discussed.