• Journal of Sasang Constitutional Medicine
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• v.22 no.4
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• pp.20-29
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• 2010

1. Objectives Our goal is to observe the feasibility of constitution discrimination from computing quantitative roughness index from dynamic friction coefficients and their gradients with the measurement device of skin friction with 3-Axis load cell sensor. 2. Methods In the traditional Korean medicine, skin diagnosis is one of the examination methods to discriminate Sasang constitution since it was known that Tae-eumin has rough skin, and Soyangin has smooth one. It is based on the skin roughness on the back of one's hand for the discrimination. The measurement device of skin friction with 3-axis load cell sensor has been developed in order to provide quantitative skin roughness through dynamic friction coefficients. The effective interval of the coefficients is obtained from the automatic sampling algorithm to use their curvature and slope. Then, Fisher's discriminant function of them makes the discrimination. 3. Results The success rate of extracting the effective interval was about 90% and the discriminant accuracy between Tae-eumin and Soyangin was 70% and 68% for men and women, respectively. The entire methods showed the possibility to distinguish between Tae-eumin and Soyangin by using stochastic properties of roughness index, which can make the entire system to include the measurement, the computation of the roughness index and the discrimination of constitution automatical. 4. Conclusions The measurement device, the automatic sampling algorithm of dynamic friction coefficients and the constitution discrimination algorithm were developed, respectively, and their combination can become the serial and automatic procedure for quantitative and objective skin diagnosis, which mimics the movement of the Oriental medical doctors' skin diagnosis. It can be applied to healthcare as well as the diagnosis of constitution in a u-Health system soon.

• Journal of the Korean Geotechnical Society
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• v.38 no.11
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• pp.97-106
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• 2022

The domestic auger-drilled pile method generally manages the driving penetration (set) value with the final stage of construction. The penetration value has been estimated by manual measurement for a long time. The automation technology is yet to be applied due to workability and high-cost limitations, despite safety issues and lack of reliability in measured results. In this study, a non-contact pile penetration measurement device was developed. Further, the field performance was verified by comparing the measurements with a conventional automation device. In addition, the on-site field quality control method was analyzed using the penetration measuring device. The field experiments confirmed that more reliable bearing capacity estimation could calculate the dynamic damping coefficient and the modified Hiley formula with the developed device. Furthermore, it can be used for pile construction management from the bearing capacity viewpoint, even for piles not subjected to dynamic load tests. 

• Korean Journal of Applied Biomechanics
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• v.16 no.2
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• pp.37-44
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• 2006

The purposes of this study were to analyze and compare EMG activities of the pectoralis major, biceps brachii, triceps brachii, and brachioradialis muscles during biceps curls using a VRT device and an elastic tubing. Fifteen male college students were recruited as subjects and they performed 10-RM and 20-RM biceps curls. For each load and device condition, the mean and peak normalized EMG levels during different phases of a biceps curl were computed. For each load and phase, paired t-test (p.05) was used to find the significant difference between two devices. ANOVA with repeated measures was also used to find the significant difference among phases in terms of EMG values for each muscle. For each load and device condition, the peak and mean EMG levels during different phases of a biceps curl were computed The significant differences between devices were found in biceps brachii for EA, MD, LD phases, and triceps brachii muscles for all phases, respectively. However, no differences were found among phases for any muscle. This indicated that elastic band could have a similar characteristics of VRT. High antagonistic muscle activity as a function of injury prevention which found particularly in VRT device may suggest that elastic tubing can be a safer training device than VRT. This also imply that elastic tubing could be very effective as a home exercise tool for rehabilitation patients and elderly people.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.1
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• pp.33-41
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• 2016

To verify that the friction damper used to high buildings as a kind of control technology of wind vibration can reduce dynamic behaviors of PTTs effectively, slip dampers in this paper are proposed to absorb the energy through relatively frictional movement of slip dampers applied to main post of a PTT (Power Transmission Tower) when dynamic displacement of a PTT occurs. The result of dynamic analysis is presented to determine the capacity of the damper system by controlling damping ratio on the resonance condition. It is observed that by installing slip dampers at a PTT the strain amplitudes of the main post caused by wind load are effectively reduced. Therefore it is shown that the proposed damper satisfies the strengthened wind-load design standards, and its efficacy was also validated experimentally by field testing.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.363-365
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• 2002

The characteristic responds of load respect to various disturbances which can usually be occurred on actual power system is very important to analyze performance and to improve load with high-technology. The disturbance power supply is designed to provide wide range of power to testing load. This device uses PLC technology to dynamic characteristic experiment and CVVF to change frequency. Also this instrument includes data acquisition system to obtain reliable data from experiment.

• Journal of Ocean Engineering and Technology
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• v.32 no.6
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• pp.427-432
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• 2018

Tidal current power is one of the energy sources of the ocean. Electricity can be generated by converting the flow energy of the current into the rotational energy of a turbine. Unlike tidal barrage, tidal current power does not require dams, which have a severe environmental impact. A floating-type tidal current power device can reduce the expensive support and installation cost, which usually account for approximately 41% of the total cost. It can also be deployed in relatively deep water using tensioned wires. The dynamic behavior of a floater and turbine force are coupled because the thrust and moment of the turbine affect the floater excursion, and the motion of the floater can affect the incoming speed of the flow into the turbine. To maximize the power generation and stabilize the system, the coupled motion of the floater and turbine must be extensively analyzed. However, unlike pile-fixed devices, there have been few studies involving the motion analysis of a moored-type tidal current power device. In this study, the commercial program OrcaFlex 10.1a was used for a time domain motion analysis. In addition, in-house code was used for an iterative calculation to solve the coupled problems. As a result, it was found that the maximum mooring load of 200 kN and the floater excursion of 5.5 m were increased by the turbine effect. The load that occurred on the mooring system satisfied the safety factor of 1.67 suggested by API. The optimum mooring system for the floating tidal current power device was suggested to maximize the power generation and stability of the floater.

• International journal of advanced smart convergence
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• v.8 no.4
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• pp.154-160
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• 2019

In this paper, we propose the miniaturization size of wearable Range of Motion(ROM) and a system that can be connected with smart devices in real-time to measure the joint movement range dynamically. Currently, the ROM of the joint is directly measured by a person using a goniometer. Conventional methods are different depending on the measurement method and location of the measurement person, which makes it difficult to measure consistently and may cause errors. Also, it is impossible to measure the ROM of joints in real-life situations. Therefore, the wearable sensor is attached to the joint to be measured to develop a miniaturize size ROM device that can measure the range of motion of the joint in real-time. The sensor measured the resistance value changed according to the movement of the joint using a load cell. Also, the sensed analog values were converted to digital values using an Analog to Digital Converter(ADC). The converted amount can be transmitted wireless to the smart device through the wearable sensor node. As a result, the developed device can be measured more consistently than the measurement using the goniometer, communication with IoT-based smart devices, and wearable enables dynamic observation. The developed wearable sensor node will be able to monitor the dynamic state of rehabilitation patients in real-time and improve the rapid change of treatment method and customized treatment.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.2
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• pp.846-864
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• 2017

Software Defined Network (SDN) realizes management and control over the underlying forwarding device, along with acquisition and analysis of network topology and flow characters through south bridge protocol. Data path Identification (DPID) is the unique identity for managing the underlying device, so forged DPID can be used to attack the link of underlying forwarding devices, as well as carry out DoS over the upper-level controller. This paper proposes a dynamic defense method based on Client-Puzzle model, in which the controller achieves dynamic management over requests from forwarding devices through generating questions with multi-level difficulty. This method can rapidly reduce network load, and at the same time separate attack flow from legal flow, enabling the controller to provide continuous service for legal visit. We conduct experiments on open-source SDN controllers like Fluid and Ryu, the result of which verifies feasibility of this defense method. The experimental result also shows that when cost of controller and forwarding device increases by about 2%-5%, the cost of attacker's CPU increases by near 90%, which greatly raises the attack difficulty for attackers.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.10
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• pp.1517-1522
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• 2015

Since electric railroad vehicle pass through repeatedly on the railroad bridge, the dynamic load that causes the change of tension of contact wire affect it constantly. In this paper, we measured the dynamic displacement of the railroad bridges to analyze the effect of tension in the catenary. A result of dynamic measurement of the longitudinal displacement, it's maximum value was 39.9mm which was lower than the primary management criteria 378mm. Also on the based of a maximum temperature, it shows a feature that the longitudinal displacement value increased as temperature rise from April to October. In terms of behavior characteristics of a tensioning device, it was confirmed to be the value of 50mm stroke movement when the temperature changes ±5℃.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.219-220
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• 2008

본 논문에서는 Windows Embedded CE의 스트림 인터페이스 드라이버(Stream Interlace Driver)를 개발하는 새로운 방법을 제안하고자 한다. Windows Embedded CE 디바이스가 부팅되면서 스트림 인터페이스 드라이버는 디바이스 매니저에 의해 메모리로 로프(Load)되고 디바이스가 꺼질 때 메모리로부터 언로드(Unload)된다. 디바인스 드라이버를 변경하여 다시 적용한 후 결과를 확인하고자 할 때 OS 바이너리 이미지를 새로 생성한 후 이미지를 다시 다운로드 하거나 드라이버를 플랫폼 빌더에서 등록한 후 해당 디바이스를 재 부팅하고 Kernel Interlace Layer(KITL)를 사용하여 그 결과를 확인할 수 있다. OS 바이너리를 새로 만드는 경우 이미지 생성과 다운로드 시간이 많이 소요되고, KITL를 사용하는 경우 매번 부팅 하는 과정을 반복해야 하기 때문에 시간이 더 소요된다. 본 논문에서는 데스크탑에서 Remote API를 이용하고 Stream Device Driver를 디바이스에 전달한 후 그것을 Remote API를 사용하여 로드하고 언로드하는 구조를 제안한다.