• Title/Summary/Keyword: Bang Hyun-seok

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Temperature Regulates Melanin Synthesis in Melanocytes

  • Kim, Dong-Seok;Park, Seo-Hyoung;Kwon, Sun-Bang;Joo, Young-Hyun;Youn, Sang-Woong;Sohn, Uy-Dong;Park, Kyoung-Chan
    • Archives of Pharmacal Research
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    • v.26 no.10
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    • pp.840-845
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    • 2003
  • Temperature change is one of the major environmental factors that influence the human skin. However, the relationship between temperature and melanogenesis has received little attention. In the present study, we investigated the effects of temperature change on melanogenesis in a mouse melanocyte cell line (Mel-Ab), and primary cultured human melanocytes. We found that Mel-Ab cells cultured at low temperatures (31 and 34$^{\circ}C$) produce less melanin than cells at 37$^{\circ}C$. These results were confirmed by experiments upon human melanocytes, demonstrating that the hypopigmenting effect of low temperatures is not cell type dependent. The observed melanin production was found to be accompanied by tyrosinase activity at each temperature, indicating that tyrosinase activity is regulated by temperature. We further examined whether the incubation period at low temperatures plays an important role in the regulation of melanogenesis. Short exposures to 27$^{\circ}C$ for 1 h or 3 h did not affect tyrosinase activity or melanin synthesis, whereas long exposures to 31$^{\circ}C$ for 2 days or 6 days significantly reduced tyrosinase activity and melanin synthesis in a duration-dependent manner. Our results suggest that exposure to low temperature and the duration of this exposure are important regulators of melanogenesis.

Performance Evaluation of an Automatic Distance Speech Recognition System (원거리 음성명령어 인식시스템 설계)

  • Oh, Yoo-Rhee;Yoon, Jae-Sam;Park, Ji-Hoon;Kim, Min-A;Kim, Hong-Kook;Kong, Dong-Geon;Myung, Hyun;Bang, Seok-Won
    • Proceedings of the IEEK Conference
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    • 2007.07a
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    • pp.303-304
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    • 2007
  • In this paper, we implement an automatic distance speech recognition system for voiced-enabled services. We first construct a baseline automatic speech recognition (ASR) system, where acoustic models are trained from speech utterances spoken by using a cross-talking microphone. In order to improve the performance of the baseline ASR using distance speech, the acoustic models are adapted to adjust the spectral characteristics of speech according to different microphones and the environmental mismatches between cross-talking and distance speech. Next we develop a voice activity detection algorithm for distance speech. We compare the performance of the base-line system and the developed ASR system on a task of PBW (Phonetically Balanced Word) 452. As a result it is shown that the developed ASR system provides the average word error rate (WER) reduction of 30.6 % compared to the baseline ASR system.

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Common XML Structure Extracting Algorithm for Applying Data Mining Techniques (데이터마이닝 기법 적용을 위한 공용 XML 구조 추출 알고리즘)

  • Jang, Min-Seok;Bang, Hyun-Jin
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.1
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    • pp.1072-1076
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    • 2005
  • Importance of XML as a target of Data Mining is growing because XML is used generally as a standard markup language for describing structured data. Especially researches have been done about extracting wanted informations by applying association rules to XML documents. But there are few development about solving the problems of method for efficiently obtaining informations from similar kinds of XML documents. To solve the problem this paper tries to suggest the method by which common XML structure is extracted form the same kinds of XML documents having a various XML schemas. The resulted schema structure is supposed to be important one as a preliminary job because it helps us to acquire the useful informations from various kinds of documents by unifying their structures.

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A Real-Time Multimedia Data Transmission Rate Control Using Neural Network Prediction Model (신경 회로망 예측 모델을 이용한 실시간 멀티미디어 데이터 전송률 제어)

  • Kim, Yong-Seok;Kwon, Bang-Hyun;Chong, Kil-To
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.2B
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    • pp.44-52
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    • 2005
  • This paper proposes a neural network prediction model to improve the valid packet transmission rate for the QoS(Quality of Service) of multimedia transmission. The Round Trip Time(RTT) and Packet Loss Rate(PLR) are predicted using a neural network and then the transmission rate is decided based on the predicted RTT and the PLR. The suggested method will improve the transmission rate since it uses the rate control factors corresponding to time of data is being transmitted, while the conventional one uses the transmission rate determined based on the past informations. An experimental set-up has been established using a Linux PC system, and the multimedia data are transmitted using UDP protocol in real time. The valid transmitted packets are about 5% higher than the one in the conventional TCP-Friendly congestion control method when the suggested algorithm was applied.

Serial Ultrasonographic Evaluation of Postpartum Uterine Involution in Miniature Schnauzer Dogs

  • Yeo, Woon-Chang;Kim, Bang-Sil;Yun, Chang-Jin;Park, Chul-Ho;Kim, Jung-Bae;Moon, Jin-San;Suh, Guk-Hyun;Oh, Ki-Seok;Son, Chang-Ho
    • Journal of Embryo Transfer
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    • v.22 no.4
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    • pp.229-234
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    • 2007
  • This study was undertaken to determine the normal appearance of the postpartum uterine involution. Postpartum changes in uterine shape, architecture, echogenicity and diameter were monitored with ultrasonography in 8 Miniature Schnauzer dogs. Vaginal discharge was observed visually during the 3 weeks of postpartum. A large amount of viscous dark green discharge changed progressively to a small amount of transparent discharge. In the uterine shape, the transverse images were crescent or polygonal at the beginning, but became circular after 16 days. At postpartum day 24, the longitudinal images of placental and interplacental sites were similar to each other The echogenicity of uterine structure was clearly distinguishable among the hyperechoic serous membrane, hypochoic myometrium, hyperechoic endometrium, and anechoic uterine contents during the first week postpartum, but afterward the interluminal boundaries and echogenicity became obscure gradually. In addition, the anechoic substance of the endometrial cavity was not observed after postpartum day 28. In the uterine diameter, the diameter of placental sites decreased markedly from 24 mm at the first day postpartum to 13 mm at day 7, and the diameter of interplacental sites decreased from 15 mm at postpartum day 1 to 10 mm at day 7. At postpartum day 65, the uterus (6.4 mm) changed little and had a uniform homogenous echo, and thus it was confirmed that uterine involution was completed at that time in Miniature Schnauzer dogs.

Efficacy and Safety of Dexmedetomidine for Postoperative Delirium in Adult Cardiac Surgery on Cardiopulmonary Bypass

  • Park, Jae Bum;Bang, Seung Ho;Chee, Hyun Keun;Kim, Jun Seok;Lee, Song Am;Shin, Je Kyoun
    • Journal of Chest Surgery
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    • v.47 no.3
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    • pp.249-254
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    • 2014
  • Background: Delirium after cardiac surgery is associated with serious long-term negative outcomes and high costs. The aim of this study is to evaluate neurobehavioral, hemodynamic, and sedative characteristics of dexmedetomidine, compared with the current postoperative sedative protocol (remifentanil) in patients undergoing open heart surgery with cardiopulmonary bypass (CPB). Methods: One hundred and forty two eligible patients who underwent cardiac surgery on CPB between April 2012 and March 2013 were randomly divided into two groups. Patients received either dexmedetomidine (range, 0.2 to $0.8\;{\mu}g/kg/hr$; n=67) or remifentanil (range, 1,000 to $2,500\;{\mu}g/hr$, n=75). The primary end point was the prevalence of delirium estimated daily via the confusion assessment method for intensive care. Results: When the delirium incidence was compared with the dexmedetomidine group (6 of 67 patients, 8.96%) and the remifentanil group (17 of 75 patients, 22.67%) it was found to be significantly less in the dexmedetomidine group (p<0.05). There were no statistically significant differences between two groups in the extubation time, ICU stay, total hospital stay, and other postoperative complications including hemodynamic side effects. Conclusion: This preliminary study suggests that dexmedetomidine as a postoperative sedative agent is associated with significantly lower rates of delirium after cardiac surgery.

New Mid-late Maturing F1 Hybrid Onion Cultivar, "Yeongpunghwang" (양파 추파형 중·만생 다수성 신품종 "영풍황")

  • Lee, Eul-Tai;Kim, Cheol-Woo;Choi, In-Hu;Jang, Young-Seok;Bang, Jin-Ki;Bae, Sang-Gyeong;Hyun, Dong-Yun;Jung, Jong-Mo;Ha, In-Jong;Kim, Seong-Bae
    • Korean Journal of Breeding Science
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    • v.41 no.4
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    • pp.587-590
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    • 2009
  • New onion hybrid cultivar, "Yeongpunghwang" was developed from cross between "MOS8", male sterile line and "Mokpo 11", pollen line by Mokpo Sub-Station, National Institute of Horticultural & Herbal Science, RDA in 2008. The crossing line was performed yield test in 2003. IT was evaluated as "Mokpo 11" in the regional yield trial test(RYT) from 2006 to 2008 during three years. This line is semi-erect plant growth type and has green leaf colour. It has broad ovate bulb shape and yellow skin colour in bulb characteristics. Plant height, leaf number, and bolting rate was 78cm, 7.9, and 3.9%, respectively. Lodging date as harvesting indicator was on 26 May. The yield potential of "Yeongpunghwang" was out-yielding 6% compare to check variety ("Sunpower") by with 8,344 kg/10a in RYT. It showed moderated cold hardness in all regional location which was conducting RYT, including Muan, Goheung, Changyeong and Andong. So this variety was recommend as a leading variety at southern area of korea.

Characteristics of Energy Consumption for a Household Refrigerator under Influence of Non-condensable Gases (가정용 냉장고의 불응축 가스량에 따른 소비 전력 특성)

  • Kim, Doo-Hyun;Hwang, Yu-Jin;Park, Jae-Hong;Chung, Seong-Ir;Jeong, Young-Man;Ku, Bon-Cheol;Lee, Jae-Keun;Ahn, Young-Chull;Bang, Sun-Wook;Kim, Seok-Ro
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.6
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    • pp.381-387
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    • 2008
  • The presence of non-condensable gases as an additional thermal resistance inside a refrigerating circuit has been found for a general refrigerator, The effect of non-condensable gases was varied by controlling the injection amount of dry air into the refrigerating circuit to increase a thermal resistance. Energy consumption tests for the refrigerator were conducted under the various amounts of non-condensable gases. The tested refrigerating circuit was the household refrigerator. As the molar fraction of non-condensable gases was increased from 0% to 1.46%, the amount of energy consumption was found to increase up to 25%. The increase of the amount of non-condensable gases in refrigerating circuit was found to result in increasing the condensation temperature at the condenser and decreasing the evaporation temperature at the evaporator, which were presumably caused by the low specific heat and increased partial pressure of non-condensable gas.

Sphigosine-1-Phosphate-Induced ERK Activation Protects Human Melanocytes from UVB-Induced Apoptosis

  • Kim, Dong-Seok;Kim, Sook-Young;Lee, Jai-Eun;Kwon, Sun-Bang;Joo, Young-Hyun;Youn, Sang-Woong;Park, Kyoung-Chan
    • Archives of Pharmacal Research
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    • v.26 no.9
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    • pp.739-746
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    • 2003
  • Ultraviolet B (UVB) is known to induce apoptosis in human melanocytes. Here we show the cytoprotective effect of sphingosine-1-phosphate (S1P) against UVB-induced apoptosis. We also show that UVB-induced apoptosis of melanocytes is mediated by caspase-3 activation and poly(ADP-ribose) polymerase (PARP) cleavage, and that S1P prevents apoptosis by inhibiting this apoptotic pathway. We further investigated three major mitogen-activated protein (MAP) kinases after UVB irradiation. UVB gradually activated c-Jun N-terminal kinase (JNK) and p38 MAP kinase, while extracellular signal-regulated protein kinase (ERK) was inactivated transiently. Blocking of the p38 MAP kinase pathway using SB203580 promoted cell survival and inhibited the activation of caspase-3 and PARP cleavage. These results suggest that p38 MAP kinase activation may play an important role in the UVB-induced apoptosis of human melanocytes. To explain this cytoprotective effect, we next examined whether S1P could inhibit UVB-induced JNK and p38 MAP kinase activation. However, S1P was not found to have any influence on UVB-induced JNK or p38 MAP kinase activation. In contrast, S1P clearly stimulated the phosphorylation of ERK, and the specific inhibition of the ERK pathway using PD98059 abolished the cytoprotective effect of S1P. Based on these results, we conclude that the activation of p38 MAP kinase plays an important role in UVB-induced apoptosis, and that S1P may show its cytoprotective effect through ERK activation in human melanocytes.

Changes in the Clinical and Epidemiological Characteristics of Trichophyton verrucosum Infection

  • Lee, Hyun Ji;Kim, Seok Min;Eun, Dong Hyuk;Lee, Weon Ju;Bang, Yong Jun;Jun, Jae Bok
    • Journal of Mycology and Infection
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    • v.23 no.4
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    • pp.99-104
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    • 2018
  • Background: Trichophyton verrucosum (T. verrucosum) is a zoophilic dermatophyte that causes ringworm in cattle and is prevalent worldwide. This dermatophyte may be responsible for various conditions, especially inflammatory skin lesions. Objective: In this study, we aimed to investigate the changes in the clinical and epidemiological characteristics of T. verrucosum infections in southeastern Korea. Methods: A total of 34 patients who visited the Catholic Skin Clinic and the Kyungpook National University Hospital in Daegu, Korea from 2005 to 2017 were diagnosed with T. verrucosum infection. The diagnosis was confirmed using fungal culture. The data were based on a retrospective survey of the medical records. Results: The annual incidence of T. verrucosum infection was very low. There was no difference in the sexual incidence. T. verrucosum infection was most common among subjects in their fifties and sixties. The highest incidence was during the month of September. The arm was most frequently involved, followed by the face. This infection was predominant in patients living in rural areas. Conclusion: These clinicoepidemiological findings provide useful information for understanding the changes in the infection caused by T. verrucosum. In particular, it was interesting to note that the incidence was very low, majority of the affected subjects were in their fifties and sixties, and the most commonly affected site was the arm.