• Electronics and Telecommunications Trends
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• v.26 no.4
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• pp.152-164
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• 2011

국내외 이동통신 시장에서 LTE로의 전환이 본격화되고 있다. 미국, 유럽, 일본 등 전세계 주요 이동통신사업자들이 LTE를 빠르게 채택하고 있으며, 국내에서도 LG U+, SKT가 금년도 7월부터 LTE 상용 서비스를 시작할 것으로 발표하여 본격적인 LTE 상용화 시대를 예고하고 있다. 올해 초 개최된 MWC 2011에서도 다양한 LTE 제품과 서비스가 등장하면서 향후 LTE 관련 업체간 경쟁은 더욱 가속화될 것으로 전망된다. 이에 따라 본 고에서는 LTE 개념 및 관련 현황을 개략적으로 살펴보고, 국내외 LTE 업계동향 및 시장전망을 분석하여 국내로의 시사점을 제시하고자 한다.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1333-1335
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• 1997

We have made disperse diazo black D(DBD) thin films using Langmuir-Blodgett(LB) and vacuum-evaporation technique. Physical and optical properties of the films were investigated. Solution was made with a concentration of $10^{-3}mol/{\ell}$ using chloroform. Moving wall apparatus, (NL-LB140S-MWC) was employed to make the LB films. X,Y and Z-type LB films were manufactured and studied UV/visible absorbance spectra and morphology of surface using atomic force microscopy(AFM). Vacuum-evaporated DB D thin films were made at a pressure of $10^{-5}$ torr. The absorption peaks were observed at 200 and 400 nm in the LB films and vacuum-deposited films. We have also studied photoluminescence spectrum of the DBD films.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.493-496
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• 1997

We have made disperse diazo black D(DB-D) ultrathin films using Langmur-Blodgett(LB) and vacuum-evaporation technique. Physical and electrical properties of the films were investigated. Solution was made with a concentration of 10$^{-3}$ mol/$\ell$ using chloroform. Moving wall apparatus (NL-LB140 S-MWC) was employed to make the LB films. X,Y and Z-type LB films were manufactured and studied by UV/visible absorbance spectra and morphology of surface using atomic force microscopy. Vacuum-evaporated DB-D think films were made at a pressure of 10$^{-5}$ torrr. The absorption peaks appear at 200 and 40nm in the LB films and vacuum-deposited films. And we have studied photoluminescence spectrum of the DB-D films. Also TGA and DSC properties of the DB-D have been observed and current -voltage characteristics of the DB-D LB films have been measured along the perpendicular direction.

• The Optical Journal
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• s.158
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• pp.55-57
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• 2015

여기저기서 드론이 뜨고 있다. 아마존이 날아오른 드론으로 고객의 문 앞까지 배달하는 모습은 일대 장관이었다. 이제 웬만한 방송에서 하늘 높이 오른 드론으로 내려다본 모습을 전송하는 것은 그저 일상일 뿐이다. 뿐만 아니라, 사람이 직접 닿을 수 없는 곳에서 드론으로 사람을 찾는다거나, 드론을 통해 고층건물의 안전도를 검사한다거나, 정찰을 하는 등 다양한 활용도가 돋보인다. 라스베가스의 세계가전전시회(CES)에서 바르셀로나의 모바일월드콩그레스(MWC)에서 그리고 뉴욕의 장난감전시회 에서도 드론은 스타로 부상했다. 이제 드론은 대중화와 상업적 성공의 기로에 서 있다. 이를 위해서는 기계적 성능이상으로 중요한 것이 드론과 사용자간의 상호작용을 통해 이루어내는 사용자 경험이다. 즉 드론을 얼마나 쉽고 편하고 정확하고 안전하게 조종할 수 있도록 만드는가가 차별화와 경쟁력의 시작이다. 만약 드론이 지금처럼 조종하기 어렵고 심지어 인명과 재산을 위협한다고 인식되면 산업적 잠재성은 그저 한여름 밤의 꿈으로 사그러들 수밖에 없다. 몇 가지 사례를 보자. 지난 2월 미국 Fox TV 생방송에서 Popular Science 잡지 편집장 Dave Mosher는 드론의 안전성에 관해서 말하고 있었다. 그 때 데모를 위해 날던 드론이 갑자기 균형을 잃으면서 추락하였다. 이 사고로 인해 드론이 안전하지 않을 수 있다는 인식이 퍼지게 되었다. 경미한 사고지만 심각한 위협감을 일으키기도 한다. 레이더에 탐지되지 않던 드론이 미국 백악관 앞마당에 추락한 것이 그런 예이다. 어떤 사용자는 재미삼아 드론을 구름 위까지 날려 보냈다. 그러더니 드론이 제어력을 상실하였고, 결국 추락하고 말았다. 다행히도 누군가의 머리 위로 떨어지지는 않았다.

• BMB Reports
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• v.31 no.1
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• pp.25-30
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• 1998

Kinetic studies of L-Alanine dehydrogenase from Bacillus subtilis-catalyzed reactions in the presence of $Zn^{2+}$ were carried out. The substrate (L-alanine) saturation curve is hyperbolic in the absence of the metal ion but it becomes sigmoidal when $Zn^{2+}$ is added to the reaction mixture indicating the positive cooperative binding of the substrate in the presence of zinc ion. The cooperativity of substrate binding depends on the xinc ion concentration: the Hill coefficients ($n_H$) varied from 1.0 to 1.95 when the zinc ion concentration varied from 0 to $60\;{\mu}m$. The inhibition of AlaDH by $Zn^{2+}$ is reversible and noncompetitive with respect to $NAD^+$ ($K_i\;=\;5.28{\times}10^{-5}\;M$). $Zn^{2+}$ itself binds to AlaDH with positive cooperativity and the cooperativity is independent of substrate concentration. The Hill coefficients of substrate biding in the presence of $Zn^{2+}$ are not affected by the enzyme concentration indicating that $Zn^{2+}$ binding does not change the polymerization-depolymerization equilibria of the enzyme. Among other metal ions, $Zn^{2+}$ appears to be a specific reversible inhibitor inducing conformational change through the intersubunit interaction. These results indicate that $Zn^{2+}$ is an allosteric competitive inhibitor and substrate being a non-cooperative per se, excludes the $Zn^{2+}$ from its binding site and thus exhibits positive cooperativity. The allosteric mechanism of AlaDh from Bacillus subtilis is consistent with both MWC and Koshland's allosteric model.

• Korean Journal of Applied Biomechanics
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• v.19 no.1
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• pp.127-138
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• 2009

The purpose of this study was to investigate range of motion (ROM) and muscle activities according to the skills of Surya Namaskara in Vinyasa Yoga. Six females (skilled 2, unskilled 4) of university students participated in this experiment. The research factors were ROM and muscle activities for static poses on Surya Namaskara in Vinyasa Yoga. The six infrared cameras (Oqus 300, Qualisys Inc, Sweden) and Zero Wire EMG (Aurion, Italy) were used to acquire raw data, and the Qualisys Track Manager and Noraxon (MyoResearch XP Master Edition, USA) were used to process data. The %MVIC and ROM were analyzed with Visual 3D (C-Motion Inc, USA) and Noraxon. In conclusion, ROM and %MVIC between two groups were remarkable different according to the static poses of Yoga, therefore instructors have to provide step-by-step information that was suitable to themselves (ROM and EMG of poses).

• Clinical and Experimental Reproductive Medicine
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• v.30 no.4
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• pp.341-350
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• 2003

Objective: The purpose of this study was to identify dietary factors related to infertility in Korean women through a case-control study. Methods: The case group was composed of 236 women who had been diagnosed as infertility in hospital. The control group of 181 healthy women with children were recruited from local immunization centers. Socio-economic status, medical history, dietary intakes using food frequency questionnaire and stress were surveyed by interview. Anthropometric measurements were made and the causes of infertility were identified through medical records. Fasting blood samples were taken from subgroup of the subjects. Results: The mean age of infertile and control groups was 31.1 and 32.4 years, respectively and the difference was statistically significant. The mean Body Mass Index of infertile women was not significantly different from control women, however, Waist/ Hip Ratio and Triceps Skinfolds Thickness were significantly lower in infertile women than in control women. The dietary intake status was generally satisfactory in both groups. The intakes of energy, protein, fat, carbohydrate, retinol, vitamin B2 and niacin were lower in infertile women than in control women. The infertile women also showed lower intakes of animal foods. No differences were found between two groups in serum concentrations of albumin, hemoglobin, Fe, TIBC, total cholesterol, HDL-cholesterol, LDL-cholesterol, triglyceride, C3, IgA, IL-2, however, infertile women showed higher levels of Zn and IgG. The stress score was higher in infertile women. Conclusions: From the results of this study, dietary factors and nutritional status do not seem to be directly related to infertility. However, the intertile women have lower nutrient intake and lower body fat content than control women. Further researches are needed according to the causes of infertility for long term to establish the relationship between dietary factors and infertility.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.11
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• pp.779-789
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• 2014

Cognitive radio (CR) technology based on geo-location database access approach and/or wideband spectrum sensing approach is absolutely vital in order to recognize available frequency bands in white spaces (WSs), and efficiently utilize shared spectrums. This paper presents a new structure for the TVWS database access protocol implementation based on Internet Engineering Task Force (IETF) Protocol to Access WS database (PAWS). A wideband compressive spectrum sensing (WCSS) scheme using a modulated wideband converter is also proposed for the TVWS utilization. The developed database access protocol technology which is adopted in both the TV band device (TVBD) and the TVWS database operates well in the TV frequency bands. The proposed WCSS shows a stable performance in false alarm probability irrespective of noise variance estimation error as well as provides signal detection probabilities greater than 95%. This paper also investigates Federal Communications Commision (FCC) regulatory requirements of TVWS database as well as European Telecommunications Standards Institute (ETSI) policy related to TVWS database. A standardized protocol to achieve interoperability among multiple TVBDs and TVWS databases, which is currently prepared in the IETF, is discussed.