• Journal of IKEEE
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• v.14 no.1
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• pp.55-64
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• 2010

In this paper, we proposed the novel TIGBT with an additional p-type MOS structure to achieve the improved trade-off between turn-off and on-state voltage drop(Vce(sat)). These low on-resistance and the fast switching characteristics of the proposed TIGBT are caused by an enhanced electron current injection efficiency which is caused by additional p-type MOS structure. In the simulation result, the proposed TIGBT has the lower on state voltage of 1.67V and the shorter turn-off time of 3.1us than those of the conventional TIGBT(2.25V, 3.4us).

• The Journal of the Korea Contents Association
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• v.16 no.3
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• pp.575-585
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• 2016

This study aimed to prove that the effect of waiting environment on perceived waiting time and service quality evaluation of airline service procedure. Survey was conducted by questionnaires that were distributed to international airlines passengers who arrived at the airport. Totally, 300 samples were circulated, and 231 samples among those were collected. According to the results, the suggested hypotheses were accepted except the regulation effect of waiting acceptability. Physical environment has positive effect on the airport and boarding gate, and human environment has more positive effect in-flight service procedure. Thus, variables are correlated among waiting environment, perceived waiting time, and service quality evaluation of airline service. Acceptability as moderating variable has no effect due to passenger's pre awareness of estimated arrival and departure travel time certainly. At the end of this study, the results of this research can be conjugable on the airline industry, however, some limitations should be discussed by further study directions.

• Journal of Computing Science and Engineering
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• v.12 no.1
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• pp.24-35
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• 2018

Deep convolutional neural network (DCNN) is an advanced technology in image recognition. Because of extreme computing resource requirements, DCNN implementation with software alone cannot achieve real-time requirement. Therefore, the need to implement DCNN accelerator hardware is increasing. In this paper, we present a field programmable gate array (FPGA)-based hardware accelerator design of DCNN targeting handwritten Hangul character recognition application. Also, we present design optimization techniques in SDAccel environments for searching the optimal FPGA design space. The techniques we used include memory access optimization and computing unit parallelism, and data conversion. We achieved about 11.19 ms recognition time per character with Xilinx FPGA accelerator. Our design optimization was performed with Xilinx HLS and SDAccel environment targeting Kintex XCKU115 FPGA from Xilinx. Our design outperforms CPU in terms of energy efficiency (the number of samples per unit energy) by 5.88 times, and GPGPU in terms of energy efficiency by 5 times. We expect the research results will be an alternative to GPGPU solution for real-time applications, especially in data centers or server farms where energy consumption is a critical problem.

• Journal of Korean Medical classics
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• v.19 no.2 s.33
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• pp.74-95
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• 2006

${\ulcorner}$Hwangje-Naegyeong${\lrcorner}$ recorded The Twenty Eight Constellations(二十八宿), the polaris, the Seven stars(北斗七星) and the Five stars(五星) and it accepted the astronomy of that time. The Twenty Eight Constellations assinged seven stars in the four cardinal points according to the ecliptic and became the criterion obsevering the way of the sun and the moon. ${\ulcorner}$Hwangje-Naegyeong${\lrcorner}$ explained that The Twenty Eight Constellations bring about the change of weather and role as criterion about the Universe Gate-Earth Door(天門-地戶). The Five Elementary attachment of the Twenty Eight Constellations is based on the direction of the earth in spring. The direction of the Twenty Eight Constellations changes from the viewpoint of celestial body in other seasons. ${\ulcorner}$Gugungpalpung-pyeon(九宮八風篇)${\lrcorner}$ and ${\ulcorner}$Selo-pyeon(歲露論)${\lrcorner}$ explained that the azimuth of the polaris and the Seven stars are related to the change of weather. ${\ulcorner}$Gigyobyeondaelon(氣交變大論)${\lrcorner}$ said that we can predict the Taegwa(太過 or Bulgeub(不及) of O-un(五運) by the orbital tracks and magnitude of the Five stars. It means that the astronomical observation is correctly performed in that time. The learning of Un-Gi(運氣學) is the study on the reciprocal action of heaven and earth. Besides the changeable disease during the 24 solar terms is related to climatic change produced by movements of heavenly bodies. For this reason, I think that the understanding of astronomical background will help to research The learning of Un-Gi.

• Korean Journal of Oriental Medicine
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• v.2 no.1
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• pp.514-550
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• 1996

There are many theory in acupuncture mechanism, so we must know the detail contents. and then we can use the acupuncture as we know. the follow article will be helpful in this part. 1. Spinal cord are role in intermediate part in somatosensorypathway also in acupuncture stumulating tract 2. Acute pain pathway started in laminae I, V of gray colmn, next are the spinothalamic tract(trigeminal spinothalamic tract in above neck part) and then go to the specific thalamic nucleus. but chronic pain in laminae II, III, VI, VII, next are spinoreticular tract(trigeminal spinoreticular tract in the neck part) and finally to the nonspecific thalamic nucleus. 3. Thalamus is very important area in somatosensory stimuation including acupuncture stumulating sensory also as a pain control center. but except this, there are Hypothalamus, Limbic system Cerebral cortex and Cerebellum as intermediator. as we Know hypothalamus is related to the emotional analgesic system with a limbic system. 4. A ${\delta$ fiber has relationship in Acute, sharp and initial pain, contrary this C fiber is related with Chronic, dull and last pain. 5. In Acupuncture mechanism of pain analgesia, there are two theory, one is gate control theory as large fiber another is stimuation produced analgesia as small diameter fier. 6. In DNIC, the stimulation sources are mechanical, thermal, heating, pain and acupuncture stimulation etc. we call these as a Heterotopic Noxious Stimulation. 7. In DNIC, SRD(Subnucleus reticularis dorsalis)is core nucleus in pain imtermediated analgesic mechanism. 8. Takeshige insisted nonacupuncture point dependent analgesic mechanism and acupuncture point dependent analgesic mechanism. and protested that Stimulation acupuncture piing evoke blocking nomacupuncture point analgesic pathway.

• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.4
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• pp.360-368
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• 2017

This paper proposes the 80-kW high-efficiency bidirectional hybrid SiC boost/buck converter using droop control for DC nano-grid. The proposed converter consists of four 20-kW modules to achieve fault tolerance, ease of thermal management, and reduced component stress. Each module is constructed as a cascaded structure of the two basic bi-directional converters, namely, interleaved boost and buck converters. A six-pack hybrid SiC intelligent power module (IPM) suitable for the proposed cascaded structure is adopted for high-efficiency and compactness. The proposed converter with hybrid switching method reduces the switching loss by minimizing switching of insulated gate bipolar transistor (IGBT). Each module control achieves smooth transfer from buck to boost operation and vice versa, since current controller switchover is not necessary. Furthermore, the proposed parallel control using DC droop with secondary control, enhances the current sharing accuracy while well regulating the DC bus voltage. A 20-kW prototype of the proposed converter has been developed and verified with experiments and indicates a 99.3% maximum efficiency and 98.8% rated efficiency.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.1
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• pp.64-75
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• 2013

As both laboratory accelerated experiment and field exposure experiment were performed, at recent, the fifth field test at five year exposures was proceeded according to long period experimental plan. Field experiment, for the adoption of the developed evaluation model, which is consisted of the analysis of chloride penetration profile at gate bridges of sea-dike completed 30 years ago was carried out during upgrading the basic evaluation model with analyzing the annual field test data. The surface concentration of chlorides was replaced to the concentration of chloride of inner concrete near the surface chlorides among his research results at basic model. Maage's suggestion function was accepted too as a diffusion coefficient of chloride after verifying the change of diffusion coefficient by analysis of annual field test data. The comparison of field data with model predictions and the estimation of remaining life time demonstrates that the proposed updated model and maintenance simulation system can be used to predict the chloride penetration profile in the marine tidal zone and appropriate repair period and cost.

• Composites Research
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• v.17 no.3
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• pp.1-7
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• 2004

In the vacuum assisted RTM (VARTM) process that has become the center of attention for manufacturing massive composite structures, a good evacuation of air in the fiber preform is recognized as the prime factor. The microvoids, or the dry spots, are formed as a result of improper gate/vent locations and the mold geometry. The non-uniform resin velocity at the flow front leads to the formation of microvoids in the fibers, whereas the air in the microvoids can migrate along with the resin flow during mold filling. The residual air in the internal voids of a composite structure may cause a degradation of the mechanical properties as well as the structural failure. In this study, a unified macro- and micro analysis methods were developed to investigate the formation and transport of air in resin during VARTM process. A numerical simulation program was developed to analyze the three-dimensional flow pattern as well as the macro- and microscopic distribution of air in a composite part fabricated by VARTM process.

• Journal of Biosystems Engineering
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• v.35 no.2
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• pp.91-99
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• 2010

A Model of small scale total mixed rations(TMR) plant which can be utilized round bales was developed, tested and analyzed in this study. This study consist of two parts. One is development of a small scale TMR plant model which was already reported at the previous paper. This is the second part of the study. For the study, a series of tests of the model plant were performed and its costs was analyzed. Also, the break-even point of the model plant by comparing with market price of commercial TMR feed was determined. Results of the research are summarized as follows ; As the results of mixing test, the average coefficient of variation(CV) value for mixing of the feed was 13.0 % at the gate of the mixer. The production cost was estimated as 8,298 won/head for dairy cattle farm and 2,495 won/head for beef cattle farm, when producing 8 batch a day. Also, it is recommended to utilize the model plant when farm size is over 79 heads for dairy cattle farm and 113 heads for beef cattle farm. As an overall conclusion, the model plant designed for farm size TMR feed mill will be very useful model for both beef cattle and dairy farms in Korea. Also it is expected that the capital investment for the model plant can be recovered with 8 months compare with purchasing commercial TMR feed if the model plant feeds 1,000 beef cattle approximately.

• Journal of Fashion Business
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• v.24 no.2
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• pp.60-67
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• 2020

This study evaluated the Skin Whitening effects of 'fermented-C.' for Atrium cosmetics using a single-arm clinical trial. Twenty female adults (mean age 42.1 ± 6.6 year) were enrolled, all participants used this cosmetic product on their face for 4 weeks. The change of brightness (L-value) was measured by spectrophotometer while subjective assessments were also obtained to find the participants opinions on whitening and their general satisfaction measured by a 5-point scale (5 for very satisfactory, 5 for satisfactory, 3 for moderate, 2 for unsatisfactory, 1 for very unsatisfactory). The participants were also questioned about any adverse effects by filling out a self-monitoring report. The average L-value increased from 62.55 ± 2.14 on day 0 to 63.22 ± 1.96 after 4 weeks corresponding to a 1.1% brightness improvement (p < 0.01). The average scores for subjective whitening and general satisfaction were better than moderate with scores of 3.6 ± 0.5 and 3.7 ± 0.7, respectively. No notable complaints were reported regarding any kind of adverse effects such as erythema, itching or burning. The clinical data collected in this study supports that fermented-C. from Atrium cosmetics has whitening potential in a safe Functional Cosmetics package.