• KIEAE Journal
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• v.16 no.5
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• pp.65-71
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• 2016

Purpose : The solar shading device carries out roles in a reduction of the cooling load and an improvement of the thermal comfort of occupants by adjusting incident solar radiation. In addition, The shading device enhances the visual sensation comfort by controlling the optical properties. In order to improve building performance and comfort of occupancy, interests in application of the shading devices are getting increasing. This study investigated the application and effectiveness of the external shading device design using statistical analysis. The outcome of this paper could be utilized for the realization of status quo and for an estimation of effectiveness of the shading device Method : The period of data gathering was between 2003 and 2014 and total 459 cases of practical building project were investigated. Firstly, this study defined qualification of the shading devices; the shading device should have minimum protruding lengths of 150mm to outside and have the function of shading control. This paper investigated application rate of the shading device in real project, regional rate of application, annual change of application, materials and types. Result : The statistical analysis showed that the application rate of shading devices was 25.7% in total 459 building design projects. The application rate in central and southern region was 25.3% and 27.0% respectively. Meanwhile, Jeju region showed 22.2%, which was the lowest rate although this area needs more shading devices. The application number of the shading device was the smallest in 2007, but the rate gradually increased after that. The applications was the largest in 2014 due to growing interest of the shading devices in the building.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.9C
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• pp.652-660
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• 2008

Applications running under embedded systems require various device drivers designed for different types and versions of the OS to manage resources effectively. In this paper, an automated device driver generator system which can generate the device drivers to be used in newer versions the target OS is proposed. In the proposed system, the structures of device drivers of specific OS are designed in the templates and stored in a library, and the target device drivers are generated by adding codes to the stored templates. Once device drivers are generated, they are registered into the kernel. The experimental results show that data transfer time has been slightly increased when compared against manually created drivers for TFT-LCD driver, USB interface keyboard/mouse driver, and AC'97 controller drivers. The code size for the generated drivers after compilation has also been increased slightly when compared with manually designed device drivers.

• Journal of Biosystems Engineering
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• v.30 no.3 s.110
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• pp.135-140
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• 2005

Vegetable transplanting operation has been wholly depended on human labor that needs 18.4 hrs per 10 acres in Korea. Since periods of vegetable transplanting operations are limited, their mechanization has been strongly demanded. This study was conducted to develop a transplanting device that was the core technology for vegetable transplanter. In order to find out transplanting track and velocity of transplanting device, a kinematic analysis software was employed. Evaluation of prototype was carried out in the circular soil bin with high speed camera. Rotary type transplanting device produced an elliptic loci when two links of different lengths were moving to the opposite direction. The length of two links was 75mm and 44mm, respectively. Maximum displacement of rotary type transplanting device was 238mm. It seemed that the transplanting elliptic loci of transplanting device were identical between the simulation output generated by kinematic analysis software and the circular soil bin test result with a high speed camera. The rotary type transplanting device can be suitable fur transplanting short height vegetable, less than 20 cm length vegetables such as Chinese cabbage and cabbage, etc.

• Journal of Acupuncture Research
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• v.32 no.4
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• pp.91-102
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• 2015

Objectives : The Oriental medical device industry is expected to continue to experience significant growth. It should increase its global market share rather than focusing on the domestic market. Countries around the world self-regulate their domestic market, so this study aims to aid in the development of a particular overseas market by introducing the U.S.(the largest market) medical device registration and approval process. Methods : For an understanding of the US medical device licensing process, we researched the relevant regulatory organization (FDA), the history, definition and classification of medical devices, the approval and 510(k) submission process related to substantial equivalence, IEC 60601-1 Edition 3, usability tests, and so on. Results : Medical devices in the United States are assigned to one of three regulatory classes: Class I, Class II and Class III, based on the level of control necessary to assure the safety and effectiveness of the device. If a company's device is classified as Class II and if it is not exempt, a 510k will be required for marketing. 1) A 510(k) is a premarket submission made to the FDA to demonstrate that the new device to be marketed is "substantially equivalent" to a legally marketed device (predicate device) 2) The IEC 60601-1 Edition 3 preparation process, which contains information related to usability, is expensive and time-consuming but a critical requirement. Conclusions : Although the U.S. market has high barriers to entry, access to this, large overseas market will encourage development of the Oriental medical device industry and commercial value enhancement is expected.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.565-569
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• 2004

The wing-body trucks are special vehicles that are designed to provide large carrying space and to protect the freights from outside impacts and bad weather. They are constructed to the structure opening and shutting three-layered aluminum top. In the middle- and large-size(above one-ton) wing-body trucks, wing-body is opened/closed by opening and shutting device of oil pressure type. But one-ton truck is constructed that its wing-body is opened/closed in manual to use helping of stay-dampers. So, we developed an electronic opening and shutting device for one-ton wing-body trucks to improve the inconvenience of usage for manually operated wing-body. The developed device is consisted of two connected links and a dc motor combined with an worm gear. The worm gear changes the rotation axis of the dc motor to a right-angled direction and transfers the torque of dc motor to the links. The two connected links open/shut the wing-body using the torque transferred from the dc motor. When the wing-body starts to be opened, the biggest torque is required from the dc motor for opening the wing-body. And as the wing-body is opened more and more, the required torque is smaller for opening the wing-body. Thus, the structure of two connected links are designed to locate at the center of worm gear so that maximum torque of the dc motor is transferred the links at the initial time starting to open wing-body. The controller of the device with open and closed buttons also is designed to protect the device from over-opening and over shutting operations. The developed device is accomplished for many experiments using actual vehicle. Those experiments show that the device has more excellent performance than the oil pressure type.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.1
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• pp.55-61
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• 2011

In this paper, the outage probability of device-to-device (D2D) uplink communication underlaying cellular networks is analyzed over Rayleigh fading. We assume that a D2D pair and M cellular user equipments share the same frequency resources. To prevent any harmful interference from a D2D transmitter to the BS, the maximum transmit power of the D2D transmitter is strictly limited. Under these assumptions, the outage probability is represented as a function of the interference-to-signal ratio from M cellular user equipments to a D2D receiver and the number of cellular user equipments, M. In addition, the interference-to-signal ratio is represented as a function of distances among D2D equipments, cellular user equipments and the BS. Simulation results validate these analytical results.

• Journal of Applied Reliability
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• v.2 no.1
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• pp.15-22
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• 2002

This paper is concerned about an Accelerated Life Test for Micro Display Device which is being used in a Projection TV, in order to find a failure mode occurred in field in a short time, to identify a major factor to affect a life, and to estimate a mean life. For this purpose, we selected a temperature as a accelerated factor to perform a test and measured degradation of display device using visual inspection and chromaticity table. In the result of Accelerated Life Test, it is confirmed that failure mode is equal to the degradation of display device by vendor and the Temperature is a major factor to affect a failure. Besides, according as the display device is turned to green as degraded, it is identified that the change of the chromaticity value is one method to measure the degree of the degradation . So, we applied the optimal condition, which consider a cost and life to lower the Temperature which is a major factor acquired by the result of ALT, to PTV design

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.12
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• pp.729-738
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• 2014

In this paper, we propose interference avoidance resource allocation scheme based on graph-coloring algorithm to introduce performance gain using spatial reuse in D2D (Device-to-Device) system. By assigning multiple D2D pairs to a single D2D resource, interference from neighboring D2D pairs is inevitable, which leads to performance degradation. Therefore, we first introduce the feedback information and the method considering the amount of information that can be practically provided by a D2D pair. Then, we propose how to construct a graph, which is corresponding to the D2D system, using the feedback information and adopt a graph-coloring algorithm to efficiently avoid interference. Simulation results show that the proposed resource allocation scheme outperforms traditional resource allocation schemes in both overall sum rate and spectral efficiency of D2D system while reducing the outage probability. Moreover, the outage probability, which indicates a failure rate of D2D communication, can be reduced by adopting the proposed scheme.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.9
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• pp.557-559
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• 2014

We propose an efficient resource allocation scheme based on interference awareness for D2D (Device-to-Device) communication in cellular networks. Recently, many researchers have studied how to allocate frequency resources to DUE (D2D User Equipment) with full interference channel information. However, it is difficult to assume a scenario where instantaneous interference information between the CUE (Cellular UE) and DUE is known to the BS (Base Station). To tackle this problem, we proposed in this paper a new scheme in which the BS allocates a resource to CUE and DUE without a full channel information and can aware interference based on only transmit power and distance between UEs. Simulation results show effectiveness of the proposed scheme.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.2
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• pp.9-16
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• 2012

In this paper, the beamforming and user scheduling scheme for device-to-device (D2D) underlaying celullar networks with partial channel state information is investigated. In the proposed scheme, cellular users whose channels are nearly orthogonal to the channel between base station and D2D receiver are selected for unitary beamforming so as to minimize the interference to the D2D receiver. The interference caused by underlaying D2D communication can be minimized by reducing the D2D transmitter's transmission power. To enhance the cellular users' throughput further, we also investigate codebook generation method in which each code vector belongs to multiple unitary code matrices. From simulation results, we show that the proposed beamforming and user scheduling scheme mitigates D2D interference to the cellular networks and the codebook generation method improves cellular users' throughput.