• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.1
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• pp.411-417
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• 2014

Special Protection Scheme(SPS) for generator tripping action is an emergency control tool that secures the power system stability by instantly tripping the pre-determined number of generators to avoid the acceleration of the remaining generators in a large-scaled power plants when a fault occurs on the drawing transmission lines. However, since the existing operating conditions of SPS are set based on a peak demand, SPS could trip more generators than required if it is activated during the off-peak demand period. For this, this paper proposes the algorithm for setting the operating conditions of SPS through the online stability evaluation with the periodically updated operating conditions of power systems. The proposed algorithm adopts COA for the accuracy and speed of the stability evaluation, and can reduce the number of tripping generators by SPS during the off-peak demand period. This results in reducing the loss of profit caused by a fault on power systems.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.3
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• pp.77-84
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• 2016

In 2012, total GHG emissions in transport sector reached 88 Million ton CO2eq. The emissions generated in the road accounted for 94% of the transport sector. Currently, there are many efforts to operate an education and campaign for eco-driving. However study for eco-friendly vehicle control considering road alignment is limited. Therefore, the purpose of this study is to address fuel-efficient driving strategy in horizontal curve section. To fulfill the goal, designed ideal freeway horizontal curve road follows regulations about road structure. And safety speed is calculated for considering vehicle's safety on horizontal curve road. Authors composed the acceleration and deceleration scenario for each horizontal curve section and generated the speed profiles that are limited by the safety speed. Speed profiles are converted into force that horizontal curve affect to fuel consumption. Then, we calculated fuel consumption using Comprehensive Modal Emission Model. Then, we developed eco-driving strategy by selecting most fuel-efficient scenario. To validate this strategy, we selected study site and compared fuel consumption for eco and manual driving. As the result, fuel consumption when driver used eco-driving was lessened by 20.73% than that of manual driving.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1649-1654
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• 1991

In 1995 the VSOP satellite, which is called MUSES-B in Japan, will be launched under the VLBI Space Observatory Programme(VSOP) promoted by ISAS(Institute of Space and Astronautical Science) of Japan. We are now developing the GPS Receiver(GPSR) and On-board Orbit Determination System. This paper describes the GPS(Global Positioning System), VSOP, GPSR(GPS Receiver system) configuration and the results of the GPS system analysis. The GPSR consists of three GPS antennas and 5 channel receiver package. In the receiver package, there are two 16 bits microprocessing units. The power consumption is 25 Watts in average and the weight is 8.5 kg. Three GPS antennas on board enable GPSR to receive GPS signals from any NAVSTARs(GPS satellites) which are visible. NAVSATR's visibility is described as follows. The VSOP satellite flies from 1, 000 km to 20, 000 km in height on the elliptical orbit around the earth. On the other hand, the orbit of NAVSTARs are nearly circular and about 20, 000 km in height. GPSR can't receive the GPS signals near the apogee, because NAVSTARs transmit the GPS signals through the NAVSTAR's narrow beam antennas directed toward the earth. However near the perigee, GPSR can receive from 12 to 15 GPS signals. More than 4 GPS signals can be received for 40 minutes, which are related to GDOP(Geometric Dillusion Of Precision of selected NAVSTARs). Because there are a lot of visible NAVSTARs, GDOP is small near the perigee. This is a favorqble condition for GPSR. Orbit determination system onboard VSOP satellite consists of a Kalman filter and a precise orbit propagator. Near the perigee, the Kalman filter can eliminate the orbit propagation error using the observed data by GPSR. Except a perigee, precise onboard orbit propagator propagates the orbit, taking into account accelerations such as gravities of the earth, the sun, the moon, and other acceleration caused by the solar pressure. But there remain some amount of calculation and integration errors. When VSOP satellite returns to the perigee, the Kalman filter eliminates the error of the orbit determined by the propagator. After the error is eliminated, VSOP satellite flies out towards an apogee again. The analysis of the orbit determination is performed by the covariance analysis method. Number of the states of the onboard filter is 8. As for a true model, we assume that it is based on the actual error dynamics that include the Selective Availability of GPS called 'SA', having 17 states. Analytical results for position and velocity are tabulated and illustrated, in the sequel. These show that the position and the velocity error are about 40 m and 0.008 m/sec at the perigee, and are about 110 m and 0.012 m/sec at the apogee, respectively.

• Korean Journal of Food Science and Technology
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• v.23 no.4
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• pp.433-436
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• 1991

Natural compounds which could improve the oxidative stability of fish oil was screened from spices, herbs and naturally occurring antioxidants. Induction period of fish oil determined from oxidation curve by Rancimat ($80^{\circ}C$) was hardly affected with the addition of water-soluble and lipid-soluble fractions of garlic, leek, sesame leave and orange peel, and of organic acids such as citric acid, EDTA and selenium. Caffeic acid, catechin, quercetin and gallic acid laurylester, however, could extend the induction periods by $2.2{\sim}3.8$ times with the addition level of 0.1%(w/w). Rosemary extract and sesamol have a marked effect in retarding oxidation of fish oil. For example, induction periods of the oil samples stabilized with 0.1 rosemary extract and 0.1 sesamol were 16.4 hr and 11.6 hr, respectively, as compared to 4.0 hr of a control. When rosemary extract was used in combination with ascorbic acid (0.02%) or 8-tocopherol (0.2%), induction period could be extended to ca. 28 hr due to the synergism.

• Journal of Astronomy and Space Sciences
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• v.21 no.4
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• pp.329-342
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• 2004

In this paper, we present preliminary feasibility studies on three types of solar observation payloads for future Korean Science and Technology Satellite (STSAT) programs. The three candidates are (1) an UV imaging telescope, (2) an UV spectrograph, and (3) an X-ray spectrometer. In the case of UV imaging telescope, the most important constraint seems to be the control stability of a satellite in order to obtain a reasonably good spatial resolution. Considering that the current pointing stability estimated from the data of the Far ultraviolet Imaging Spectrograph (FIMS) onboard the Korean STSAT-1, is around 1 arc minutes/sec, we think that it is hard to obtain a spatial resolution sufficient for scientific research by such an UV Imaging Telescope. For solar imaging missions, we realize that an image stabilization system, which is composed of a small guide telescope with limb sensor and a servo controller of secondary mirror, is quite essential for a very good pointing stability of about 0.1 arcsec. An UV spectrograph covering the solar full disk seems to be a good choice in that there is no risk due to poor pointing stability as well as that it can provide us with valuable UV spectral irradiance data valuable for studying their effects on the Earth's atmosphere and satellites. The heritage of the FIMS can be a great advantage of developing the UV spectrograph. Its main disadvantage is that two major missions are in operation or scheduled. Our preliminary investigations show that an X-ray spectrometer for the full disk Sun seems to be the best choice among the three candidates. The reasons are : (1) high temporal and spectral X-ray data are very essential for studying the acceleration process of energetic particles associated with solar flares, (2) we have a good heritage of X-ray detectors including a rocket-borne X-ray detector, (3) in the case of developing countries such as India and Czech, solar X-ray spectrometers were selected as their early stage satellite missions due to their poor pointing stabilities, and (4) there is no planned major mission after currently operating Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI) mission. Finally, we present a preliminary design of a solar X-ray spectrometer covering soft X-ray (2 keV) to gamma ray (10 MeV).

• Journal of Korea Technology Innovation Society
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• v.20 no.3
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• pp.576-606
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• 2017

It is more salient in the high-tech industry to cooperate even among competitors in order to promptly respond to the changes in product architecture. In this sense, 'co-opetition,' which is the combination word between 'cooperation' and 'competition,' is the new business term in the strategic management and represents the two concepts "simultaneously co-exist." From this view, this study set up the research purposes as follows: 1) investigating the corporate managerial and technological behavioral characteristics in the co-opetition of the global display industry. 2) verifying the emerging factors during the co-opetition behavior hereafter. 3) suggesting the strategic direction focusing on the co-opetition behavioral characteristics. To this end, this study used co-word network analysis to understand the structure in context level of the co-opetition. In order to understand topics on each network, we clustered the keywords by community detection algorithm based on modularity and labeled the cluster name. The results show that there were increasing patterns of competition rather than cooperation. Especially, the litigations for mutual control against Korean firms much more severely occurred and increased as time passed by. Investigating these network structure in technological evolution perspective, there were already active cooperation and competition among firms in the early 2000s surrounding the issues of OLED-related technology developments. From the middle of the 2000s, firm behaviors have focused on the acceleration of the existing technologies and the development of futuristic display. In other words, there has been competition to take leadership of the innovation in the level of final products such as the TV and smartphone by applying the display panel products. This study will provide not only better understanding on the context of the display industry, but also the analytical framework for the direction of the predictable innovation through analyzing the managerial and technological factors. Also, the methods can support CTOs and practitioners in the technology planning who should consider those factors in the process of decision making related to the strategic technology management and product development.

• KIPS Transactions on Computer and Communication Systems
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• v.6 no.6
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• pp.271-280
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• 2017

In this paper, we propose a new safety system composed of wearable devices, driver's seat belt, and integrating controllers. The wearable device and driver's seat belt capture driver's biological information, while the integrating controller analyzes captured signal to alarm the driver or directly control the car appropriately according to the status of the driver. Previous studies regarding driver's safety from driver's seat, steering wheel, or facial camera to capture driver's physiological signal and facial information had difficulties in gathering accurate and continuous signals because the sensors required the upright posture of the driver. Utilizing wearable sensors, however, our proposed system can obtain continuous and highly accurate signals compared to the previous researches. Our advanced wearable apparatus features a sensor that measures the heart rate, skin conductivity, and skin temperature and applies filters to eliminate the noise generated by the automobile. Moreover, the acceleration sensor and the gyro sensor in our wearable device enable the reduction of the measurement errors. Based on the collected bio-signals, the criteria for identifying the driver's condition were presented. The accredited certification body has verified that the devices has the accuracy of the level of medical care. The laboratory test and the real automobile test demonstrate that our proposed system is good for the measurement of the driver's condition.

• Journal of Ginseng Research
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• v.3 no.2
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• pp.168-186
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• 1979

Three hundred gram of Korean ginseng root was extracted with 95% ethanol on a boiling water bath for about 300 hr. Evaporation of alcohol yieled 50.2g of dark brown residue which was used by dissolving 4 mg of the residue in 1 ml of physiological saline. The ginseng group and the saline group received each day 0.5 ml per 100 g body weight of ginseng extract and physiological saline, respectively. Both the ginseng and saline group with stress were exposed to positive radial acceleration (1∼29g), cold (5$^{\circ}C$, 0$^{\circ}C$ &-10$^{\circ}C$) and heat (35$^{\circ}C$) environment, and surgical stress. After termination of the last stress, the tolerance, body weight, visceral organ weight, basal metabolism rate, rectal temperature, the number of erythrocyte and leucocyte, hemoglobin level, hematocrit ratio, total serum protein content and it's fraction and the content of adrenal ascorbic acid in the experimental animal exposed to stress were measured and at the corresponding periods, the same measurements were also carried out with the ginseng and the saline groups without stress exposure (serving as control). Results obtained were as follows. 1. Administration of ginseng does depressed the decrease of the tolerance, body weight, visceral organ weight, basal metabolism rate, the number of erythrocyte, hemoglobin value, hematocrit ratio and the A/G ratio in the mice and rats exposed to various stress. 2. The change of the rectal temperature, eosinophile counts, total serum protein content and the content of adrenal ascorbic acid of ginseng group that exposured to various stress facilitates the reaction to, and accelerates the recovery from the stress. 3. Even after hypophysectomy which served the link between the central and the peripheral portion of the stress mechanism, the adrenal ascorbic acid content of ginseng group decreased significantly more than that of the saline group 30 min. after administration of ACTH, while the value approached the normal level significantly closer in the ginseng group than in the saline group 1 and 2 hr after ACTH administration. Judging from the above results, it is concluded that administration of ginseng extract tolerated the experimental animals under the environment of stressfu1 stmuli, although the ginseng has no significant influence upon the stress mechanism in the absence of stressful stimuli. The site of action of the ginseng appears to be in the peripheral portion of the stress mechanism.

• Journal of IKEEE
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• v.23 no.4
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• pp.1457-1460
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• 2019

In this paper, we proposed the development of a mixed sensor parts for integrated radiation exposure protection fireman's life-saving alarm that can be location-tracked and irradiated. To measure radiation exposure dose, we use the PIN-Diode radiation measurement sensor module, a semi-conductive radiation measurement sensor that can minimize size and weight. The design for removing leakage current is carried out to enhance the characteristics of the radiation measurement sensor using PIN-Diode. The IMU sensor module is used to estimate the location of the current fireman at the same time as the accident estimate by adding together the data and the values for acceleration on the three axis. Experiments were conductied by an authorized testing agency to determine the efficiency of the proposed mixed sensor parts for integrated radiation exposure protection fireman's life-saving alarms. The cumulative dose measurement range was measured in the range of 10 μSv to 10 mSv, the highest level in the world. The accuracy was measured from ±6.3% to ±9.0% (137 Cs) and normal operation was found at the international standard of ±15%. In addition, positional accuracy was measured within ±10%, resulting in a high level of results, demonstrating its effectiveness. Therefore, it is expected that more firemen will be able to provide with superior performance integrated radiation exposure protection fireman life-saving alarm.

• Science of Emotion and Sensibility
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• v.13 no.1
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• pp.103-110
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• 2010

TPR(Total Physical Response) is a new representative learning method for children's education. Today's approach to TPR has focused on signals from a user which becomes input data in a human-computer interaction, but the accuracy of sensing from body signals(e. g. motion and voice) isn't so perfect that it seems difficult to apply on an education system. To overcome these limits, we suggest a mediating interface device which can detect the user's motion using correct numerical values such as acceleration and angular speed. In addition, we suggest new design requirements for the mediating device through analyzing children's behavior as human factors by ethnography research and protocol analysis. As a result, we found that; children are unskilled in physical control when they use objects; tend to lean on an object unconsciously with touch. Also their behaviors are restricted, when they use objects. Therefore a mediating device should satisfy new design requirements which are make up for unskilled handling, support familiar and natural physical activity.