• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.629-630
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• 2017

Recently, the number of patients with habitual vertebrae is increasing due to inappropriate postures and habits while sitting on a chair for a long time, because modern people have a great deal of work and studying due to a lot of work and study. Therefore, it is necessary to prevent such a disease through real-time monitoring and to present a guide for the user to recognize the importance of correct posture. In this study, we implemented a posture discrimination system which can help users to calibrate posture by judging the user's sitting position and feedback by using a pressure sensor based weight distribution system. We analyzed the distribution pattern of body weight to determine one normal posture and six abnormal postures. If the abnormal posture is maintained constantly, the implementation of the application that induces the right posture by ringing the notification is described.

• Journal of IKEEE
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• v.21 no.3
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• pp.195-201
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• 2017

High-power wireless transmission system becomes a key technology for the advance of battery-powered devices. The wireless power transfer devices are currently dominated by the inductive and capacitive wireless power transfer systems, which have relatively low power transmission capacity and low efficiency rather than the wired power transmission. The work presented in this paper proposes an alternative method of high-power transmission system, based on a variable speed motor system with a magnetic coupling. It enables high-capacity power transmission, high efficiency, and low possibility of failures, and the performance of the proposed scheme is verified by simulation and experiments.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.62-63
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• 2005

Recently, a tiny piezoelectric linear motor using a vibration made of the transducer has been invented. The motor consists of a shaft, mobile element, and piezoelectric transducer using a piezoelectric radial mode bimorph disk. The fringe of the bimorph disk is fixed firmly which means this area has no degree of freedom. Therefore, the radial mode of the tranducer transfers to the flexurd mode. The mobile elements move along the shaft by the impact force generated by the flexurd mode of the piezoelectric transducer. The piezoelectric ceramic disks have thickness of 0.1 mm and diameter of 3.5 mm. The elastic disk is introduced between two disks of the ceramic, which has thickness of 0.1 mm and diameter of 3.8 mm. The fringe of the elastic disk is fixed by a brass cylinder which height is 1.2 mm. The Pyrex shaft is used which has diameter of 1 mm and height of 10 mm. The motors are operated at their resonant frequencies. The dynamic properties of the motor have been intensively measured and analyzed according to the applied voltage wave forms at the resonant frequencies. As the sawtooth and rectangular voltage waves are applied, the velocity, the thrust force, and the velocity dependence of the mobile position are measured. The dynamic characteristics are also analyzed within a period of each wave using laser vibrometer. The velocity of the mobile is moderately constant along the shaft. The better dynamic characteristics are obtained in the case of applying the rectangular wave.

• Korean Journal of Microbiology
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• v.40 no.1
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• pp.7-11
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• 2004

eIF5B is a translation initiation factor that delivers Met-$tRNA^{Met}$ to AUG start codon and subsequently joins the small and large ribosomes. In order to study the function of eIF5B encoded by FUN12, we constructed FUN12 which lacked 5' end of its sequence. We found that this construct lacking almost all of its promoter in pRS plasmid partially complemented slow growth phenotype of fun12 deletion strain. Interestingly, this construct expressed N-terminally truncated eIF5B and its expression level was about 5% of that of wild type eIF5B. Low amount of the eIF5B expressed additionally in fun12 deletion strain played a direct role as a limiting factor for its growth. This limiting factor eIF5B in those strains also modulates activities of overall translation in vitro.

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.6
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• pp.505-510
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• 2016

This paper presents a searching method of corresponding points robust to rotational error for scan-matching used for SLAM(Simultaneous Localization and Mapping) in mobile robot. A differential driving mechanism is one of the most popular type for mobile robot. For driving curved path, this type controls the velocities of each two wheels independently. This case increases a wheel slip of the mobile robot more than the case of straight path driving. And this is the reason of a drifting problem. To handle this problem and improves the performance of scan-matching, this paper proposes a searching method of corresponding points using extraction of a closest point based on rotational radius of the mobile robot. To verify the proposed method, the experiment was conducted using LRF(Laser Range Finder). Then the proposed method is compared with an existing method, which is an existing method based on euclidian closest point. The result of our study reflects that the proposed method can improve the performance of searching corresponding points.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.4
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• pp.59-70
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• 2021

An experimental study was conducted to observe the spray characteristics for different flow rates and rotating speeds of a rotating fuel nozzle of a slinger combustor. The water spray ejected from the nozzle orifice was visualized using a high-speed camera and a light source. It was confirmed that the atomization was improved, as the flow rate decreased and rotating speed increased. The characteristic maps for the spray characteristics and performance parameters showed that the aerodynamic Weber number and the liquid-air momentum flux ratio were associated with the liquid primary breakup, and the liquid-air momentum flux ratio and Rossby number were closely correlated with the liquid ejection mode.

• Horticultural Science & Technology
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• v.18 no.5
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• pp.594-598
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• 2000

This study was carried out to investigate the tissue-specific expression of ${\beta}$-glucuronidase (gus) gene driven by endosperm-specific promoter (Z4 promoter) in the transgenic tobacco and to find out inheritance pattern of transgene to the next generation. Tobacco (Nicotiana tabaccum cv. Havana SR1) was transformed with Agrobacterium tumerfaciens LBA4404 harboring BV3 construct containing gus gene driven by Z4 promoter and a kanamycin resistant gene. Seven hundred bp PCR products, indicating the presence of npt II gene, were found in the all eight transformants by PCR analysis using nptII primers. To study the expression pattern of the two different kind of promoters, leaf disks of the Z4pro-gus-transformed plants and 35Spro-gus-transformed plants were analyzed histochemically for gus activity. As a result, leaf disks of Z4pro-gus-transformed plants showed very weak and partial positive gus activity. In contrast, leaf disks of 35Spro-gus-transformed plants showed relatively strong positive gus activity. To investigate the expressed position of Z4 promoter, seeds from Z4pro-gus-transformed plants and 35Spro-gus-transformed plants were analyzed histochemically for gus activity. Z4pro-gus-transformed seeds showed positive gus activity restricted to the endosperm. However, the blue-colored product in 35Spro-gus-transformed seeds was observed in all the area including endosperm. Kanamycin resistance assay showed that transgenes were stably inherited to next generation in all lines.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.10a
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• pp.21-25
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• 2001

기계부품의 소형화 , 고속화, 그리고 저공해, 저소음이 요구되는 세계적인 추세에서 정밀가공기술은 기계 및 전자산 업에서 중요한 위치를 차지하게 되었다. 특히, 무심연삭공정(Centerless Grinding)은 높은 생산성과 정확한 치수 형성의 능력이 있어서 원통형상을 가공하는 중요한 생산공정으로 사용되어 왔다. 예컨대 VCR의 소형 축. Computer Disk Drive, 초소형 모터, 연료분사기등은 쎈터레스 연삭공정을 통하여 높은 정밀도를 얻고 있다. 하지만 이 공정의 특수성과 측정의 어려움으로 인하여 이러한 정밀형상의 형성과정은 아직도 잘 밝혀져있지 않다. 무심연연삭 공정에서는 부품이 기계에 고정되어 있지 않고 공작물 받침날 위에 올려져 있으며 조절바퀴와 연삭바퀴 사이에 눌려져 있다. 조절바퀴가 마찰력으로 공작물을 돌려주며 연삭바퀴에서 연삭가공이 일어나게 된다. 조절바퀴와 연삭바퀴사이의 거리는 기계 자체의 탄성변형으로 인하여 항시 변화하게 되며 이 거리의 변화가 공작물의 정밀형상 형성에 결정적인 영향을 미치게 된다. 본 연구에서는 무심연삭공정중 공작물과 받침날, 조절바퀴, 연삭바퀴의 상대운동을 기하학적으로 해석하였다. 특히 간섭조건을 사용하여 실제 공작물의 운동을 해석하여 순간 명목 절삭깊이를 구하였다. 또한 연삭 특성실험식을 이용하여 수직 연삭력을 구하고 연삭기의 탄성변형을 구하여 순간 실제 절삭깊이를 계산하였다. 그로부터 진원도형성에 관한 기본식을 유도하였다. 본 연구에서 유도된 진원도 형성 식을 이용하여 실험과 동일한 조건으로 컴퓨터 시뮬레이션을 수행하였다. 그리고 원형중의 어떤 이상형상, 즉, 홈또는 돌기는 반복되어서 다른 돌기 또는 홈을 형성 하게되며 그 반복주기는 공작물이 조절바퀴와 연삭바퀴위에 떠있는 각도에 따라 결점 됨을 확인하였다.'유창성' 에 그 목표를 두고 있는 점을 감안한다면, 시작단계부터 반드시 정확한 발음을 지녀야 하는 가의 문제도 생각해 볼 필요가 있다. 경우에 따라서는, 정확한 발음은 그 언어에 대한 숙련도가 점차 높아짐에 따라 이와 병행하여 이루어지는 경우도 흔히 경험하는 일이기 때문이다. 결국 초등영어 교육과정에도 명시되어 있듯이 '...영어에 대한 친숙함과 자신감을 심어주고, 영어에 대한 흥미와 관심을 지속적으로 유지시키는 것이 중요하기' 때문에 무엇보다 중요한 측면은 흥미와 관심을 유지시키는 지적인 학습활동보다는 정의적인 학습활동의 전개가 필요하다고 하겠다. 유리된 AA의 세포독설과 관련된 세포내의 역할에 대해 의문이 제기되었다., PCL에 SOD-1도 경미하게 나타났으나, 경련이 나타난 쥐에서는 KA만을 투여한 흰쥐와 구별되지 않았다. 이상의 APT의 항산화 효과는 KA로 인한 뇌세포 변성 개선에 중요한 인자로 작용할 것으로 사료되나, 보다 명확한 APT의 기전을 검색하고 직접 임상에 응응하기 위하여는 보다 다양한 실험 조건이 보완되어야 찰 것으로 생각된다. 항우울약들의 항혈소판작용은 PKC-기질인 41-43 kD와 20 kD의 인산화를 억제함에 기인되는 것으로 사료된다.다. 것으로 사료된다.다.바와 같이 MCl에서 작은 Dv 값을 갖는데, 이것은 CdCl$_{4}$$^{2-}$ 착이온을 형성하거나 ZnCl$_{4}$$^{2-}$ , ZnCl$_{3}$$^{-}$같은 이온과 MgCl$^{+}$, MgCl$_{2}$같은 이온종을 형성하기 때문인것 같다. 한편 어떠한 용리액에서던지 NH$_{4}$

• Journal of the Society of Cosmetic Scientists of Korea
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• v.32 no.3 s.58
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• pp.135-140
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• 2006

Nuclear factor-kappaB (NF-kappaB) is a critical transcription factor for maximal expression of many of the cytokines that are involved in the pathogenesis of inflammatory diseases. In this study, we found that 12 plant extracts among 200 plants, namely, Forsythia koreana, Capsicum annuum L, Mentha arvenis, Duchesnea chrysantha, Morus alba, Saururus Chinenis (Lour) Baill, Pine needle, Zingiber mioga (Thunb.), Roscoe, Houttuynia, Prunus yedoenis, Sasa quelpaertenis, significantly inhibited LPS- induced NF-kappaB activation in a concentration-dependent manner. Additionally, 12 plant extracts were found to have antioxidant activities in DPPH assay Therefore, we have attempted to determine whether 12 herbal extracts could inhibit the expression of cytokines possessing NF-kappaB promoter in their promoter regions. Consistently 12 herbal extracts inhibited LPS-induced production of TNF alpha and interleukin-8 (IL-8). These results show that 12 herbal extracts suppresses the production of pro-inflammatory mediators through the inhibition of the NF-kappaB signaling pathway, we suggest that 12 herbal extracts can be used as a anti-inflammatory and soothing agent.

• Korean journal of applied entomology
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• v.56 no.1
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• pp.19-28
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• 2017

Polydnaviruses (PDVs) are a group of double-stranded DNA viruses symbiotic to some endoparasitoid wasps. Cotesia plutellae bracovirus (CpBV) is a PDV symbiotic to an endoparasitoid wasp, C. plutellae, parasitizing young larvae of Plutella xylostella. An early expressed gene, CpBV-ELP1, plays an important role in the parasitism by suppressing host cellular immunity by its cytotoxic activity against hemocytes. This study aimed to test its oral toxicity against insect pest by expressing it in a recombinant tobacco plant. A recombinant CpBV-ELP1 protein was produced using a baculovirus expression system and secreted to cell culture medium. The cell cultured media were used to purify CpBV-ELP1 by a sequential array of purification steps: ammonium sulfate fractionation, size exclusion chromatography, and ion exchange chromatography. Purified rCpBV-ELP1 exhibited a significant cytotoxicity against Spodoptera exigua hemocytes. CpBV-ELP1 was highly toxic to the fifth instar larvae of S. exigua by injection to hemocoel. It also showed a significant oral toxicity to fifth instar larvae of S. exigua by a leaf-dipping assay. CpBV-ELP1 was cloned into pBI121 vector under CaMV 35S promoter with opaline synthase terminator. Resulting recombinant vector (pBI121-ELP1) was used to transform Agrobacterium tumefaciens LBA4404. The recombinant bacteria were then used to induce callus of a tobacco (Nicotiana tabacum Xanthi) leaves and subsequent generation (T1) plants were selected. T1 generation tobacco plants expressing CpBV-ELP1 gave significant insecticidal activities against S. exigua larvae. These results suggest that CpBV-ELP1 gene can be used to control insect pests by constructing transgenic crops.