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Design of VCO(Voltage Controlled Oscillator) for mobile communication with a built-in voltage regulator (전압 레귤레이터를 내장한 이동통신용 VCO(Voltage Controlled Oscillator) 설계)

  • Cho, Hyon-mook
    • The Journal of the Acoustical Society of Korea
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    • v.16 no.4
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    • pp.76-84
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    • 1997
  • In this paper, one of the core components of a mobile communication system, VCO(Voltage Controlled Oscillator) IC is designed. The VCO IC was designed, have realized as LC turned oscillator using varicap. LC sinusoidal tuned oscillator generally requires external inductors and thus remainding circuit is implemneted in monolithic IC. The circuit is fabricated using an 15 mask IC process and has a die size of 1150um${\times}$780um. The tests showed that VCO was operated at frequencies in the regions between 880MHz-915MHz in the control voltage range of 1V to 3V at 5V supply voltage and as the power supply was varied from 4.5V to 5.5V, the frequency varied 425KHz/V. The VCO IC has frequency shift of 1.97MHz/T, carrier level of -7dBm and power consumption of 16.7mA. Also it has phase noise of -80dBc/Hz, offset at 50KHz and harmonic response of center frequency is -41dBm. For the future development of the transceiver 1 chip, the previously mentioned external devices need to be incorporated into Si MMIC.

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Preference for the Spatial Planning Elements of Units m Senior Congregate Housing according to Pre-Senior People (예비노인층의 노인공동생활주택 개별공간 계획요소에 대한 선호분석)

  • Hong Yi-Kyung;Oh Hye-Kyung
    • Journal of Families and Better Life
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    • v.23 no.2 s.74
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    • pp.37-47
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    • 2005
  • Korea is having entered the Ageing Society since 2000 and expected to be the Aged Society by 2019. Proliferation of the nuclear families, attitude shift of supporting the senior people and higher participation of married women in public life as well as the steadily increasing senior population have caused the need for development of the facilities or housings for the senior people. This study is based on the assumption that the congregate housing as one of the options for those senior people who are healthy enough do not need the nursing home. For the questionnaire survey, the preference of 500 Korean pre-senior people on spatial planning elements of units for the senior congregate housing was investigated. The collected data are analysed using SPSS 10.0 for Windows to deduce frequency, percentage, average, Chi-squared test with cross-tabulations. The results of this study were as follows; Most of respondents preferred to the size of 11-15pyung(for single), 21-25pyung(for couple). The type of spatial composition was preferred one-room type(for single), 1-2 bedroom type with kitchen (for couple). And they preferred L/DK type. Also, they preferred furnished units not to bring their own furniture when relocating to the senior congregate housing, which was somewhat different result from previous studies. There were significant differences between preferred spatial planning elements and gender, income, and level of education.

Improvement of Electrical Performance and Stability in ZnO Channel TFTs with Al Doped ZnO Layer (Al Doped ZnO층 적용을 통한 ZnO 박막 트랜지스터의 전기적 특성과 안정성 개선)

  • Eom, Ki-Yun;Jeong, Kwang-Seok;Yun, Ho-Jin;Kim, Yu-Mi;Yang, Seung-Dong;Kim, Jin-Seop;Lee, Ga-Won
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.28 no.5
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    • pp.291-294
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    • 2015
  • Recently, ZnO based oxide TFTs used in the flexible and transparent display devices are widely studied. To apply to OLED display switching devices, electrical performance and stability are important issues. In this study, to improve these electrical properties, we fabricated TFTs having Al doped Zinc Oxide (AZO) layer inserted between the gate insulator and ZnO layer. The AZO and ZnO layers are deposited by Atomic layer deposition (ALD) method. I-V transfer characteristics and stability of the suggested devices are investigated under the positive gate bias condition while the channel defects are also analyzed by the photoluminescence spectrum. The TFTs with AZO layer show lower threshold voltage ($V_{th}$) and superior sub-threshold slop. In the case of $V_{th}$ shift after positive gate bias stress, the stability is also better than that of ZnO channel TFTs. This improvement is thought to be caused by the reduced defect density in AZO/ZnO stack devices, which can be confirmed by the photoluminescence spectrum analysis results where the defect related deep level emission of AZO is lower than that of ZnO layer.

A Study on the Alternative Environmental Assessment System in KOREA : Applying New Conceptual Model(APEMI IA MODEL) into Impact Assessment for Better Integrated Decision-Making (대안적 환경평가 시스템 연구: 통합적 의사결정을 위한 새로운 개념의 영향평가모형(APEMI IA MODEL)의 국내 적용방안 탐색)

  • Kim, Im Soon;Han, Sang Wook
    • Journal of Environmental Impact Assessment
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    • v.14 no.4
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    • pp.179-193
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    • 2005
  • As the world's attention turns to sustainability and the considerations of cumulative effects, the concept of Strategic Environmental Assessment(SEA) has become more significant and urgent and increasing number of countries and international organizations now undertake some forms of SEA. The term SEA, however, is variously defined and understood; generally it means a formal process of systematic analysis of the environmental effects on development policies, plans, programmes and other proposed strategic actions. This process extends the aims and principles of EIA upstream in the decision-making process, beyond the project level in which major alternatives are still open. There is a shift toward more integrative approaches and greater use of Environmental Impact Assessment (EIA) and Strategic Environmental Assessment (SEA) as sustainability tools in cooperation with Environmental Management System (EMS). Currently, Korea has EIA system and Prior Environmental Review System (PERS) which is different type of SEA as Environment Assessment (EA) system. APEMI IA MODEL integrated following three pillar(refer to attached figure.1) ; First pillar symbolized decision making cycle with planning process. Second pillar symbolized integrated assessment which tying SEA and EIA with specific impacts assessment(eg: social impact assessment, economic impact assessment, health impact assessment etc) in cooperation with EMS. Third pillar symbolized EA best practical procedure of International Association for Impact Assessment(IAIA). Considering the above, we applied new conceptual model(APEMI IA MODEL) into Impact Assessment for better integrated decision-making in KOREA as an alternative IA system(IS IA MODEL A and B refer to attached figure 4, 5).

Effect of Gynosaponin on Rumen In vitro Methanogenesis under Different Forage-Concentrate Ratios

  • Manatbay, Bakhetgul;Cheng, Yanfen;Mao, Shengyong;Zhu, Weiyun
    • Asian-Australasian Journal of Animal Sciences
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    • v.27 no.8
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    • pp.1088-1097
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    • 2014
  • The study aimed to investigate the effects of gynosaponin on in vitro methanogenesis under different forage-concentrate ratios (F:C ratios). Experiment was conducted with two kinds of F:C ratios (F:C = 7:3 and F:C = 3:7) and gynosaponin addition (0 mg and 16 mg) in a $2{\times}2$ double factorial design. In the presence of gynosaponin, methane production and acetate concentration were significantly decreased, whereas concentration of propionate tended to be increased resulting in a significant reduction (p<0.05) of acetate:propionate ratio (A:P ratio), in high-forage substrate. Gynosaponin treatment increased (p<0.05) the butyrate concentration in both F:C ratios. Denaturing gradient gel electrophoresis (DGGE) analysis showed there was no apparent shift in the composition of total bacteria, protozoa and methanogens after treated by gynosaponin under both F:C ratios. The real-time polymerase chain reaction (PCR) analysis indicated that variable F:C ratios significantly affected the abundances of Fibrobacter succinogenes, Rumninococcus flavefaciens, total fungi and counts of protozoa (p<0.05), but did not affect the mcrA gene copies of methanogens and abundance of total bacteria. Counts of protozoa and abundance of F.succinogenes were decreased significantly (p<0.05), whereas mcrA gene copies of methanogens were decreased slightly (p<0.10) in high-forage substrate after treated by gynosaponin. However, gynosaponin treatment under high-concentrate level did not affect the methanogenesis, fermentation characteristics and tested microbes. Accordingly, overall results suggested that gynosaponin supplementation reduced the in vitro methanogenesis and improved rumen fermentation under highforage condition by changing the abundances of related rumen microbes.

Several systems for 1Giga bit Modem

  • Park, Jin-Sung;Kang, Seong-Ho;Eom, Ki-Whan;Sosuke, Onodera;Yoichi, Sato
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.1749-1753
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    • 2003
  • We proposed several systems for 1Giga bit Modem. The first, Binary ASK(Amplitude Shift Keying) system has a high speed shutter transmitter and no IF(Intermediate Frequency) receiver only by symbol synchronization. The advantage of proposed system is that circuitry is very simple without IF process. The disadvantage of proposed system are that line spectrum occurs interference to other channels, and enhancement to 4-level system is impossible due to its large SNR degradation. The second, Binary phase modulation system has a high speed shutter transmitter and IF-VCO(IF-Voltage Controlled Oscillator) control by base-band phase rotation. Polarity of shutter window is changed by the binary data. The window should be narrow same as above ASK. The advantage of proposed system is which error rate performance is superior. The disadvantage of proposed system are that Circuitry is more complex, narrow pull-in range of receiver caused by VCO and spectrum divergence by the non-linear amplifier. The third, 4-QAM(Quadrature Amplitude Modulation)system has a nyquist pulse transmitter and IF-VCO control by symbol clock. The advantage of proposed system are that signal frequency band is a half of 1GHz, reliable pull-in of VCO and possibility of double speed transmission(2Gbps) by keeping 1GHz frequency-band. The disadvantage of proposed system are that circuit complexity of pulse shaping and spectrum divergence by the non-linear amplifier.

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Nurse Staffing Levels and Proportion of Hospitals and Clinics Meeting the Legal Standard for Nurse Staffing for 1996~2013 (의료법에 의거한 의료기관 종별 간호사 정원기준 충족률 추이 분석)

  • Cho, Sung-Hyun;Lee, Ji-Yun;June, Kyung-Ja;Hong, Kyung Jin;Kim, Yunmi
    • Journal of Korean Academy of Nursing Administration
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    • v.22 no.3
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    • pp.209-219
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    • 2016
  • Purpose: To analyze the proportion of medical institutions meeting the legal standard for nurse staffing. Methods: Data collected from 29,282 institutions between 1996 and 2013 were analyzed. Nurse staffing was measured as daily patient census per registered nurse (RN). The standard for general hospitals, hospitals, and clinics is 2.5 or less, and that for long-term care hospitals is 6.0 or less of the daily patient census per RN. Clinics may substitute nursing assistants for RNs by 50% or 100% depending on their daily inpatient census; long-term care hospitals may substitute nursing assistants for RNs by two thirds of the required number of RNs. Results: The proportion of general hospitals, hospitals, clinics, and long-term care hospitals meeting the standards was 63%, 19%, 63%, and 94%, respectively, in 2013. While general hospitals had an increase in the proportion during the 1996-2013 period, small changes were found in hospitals and clinics. In 2013, nurses were estimated to care for 16 (interquartile range: 12~24) patients per shift in general hospitals. Three quarters of clinics had no RNs in 2013. Conclusion: Many medical institutions did not meet the legally mandated minimum staffing level. The government must implement policy actions for all medical institutions to meet the legal standards.

Financial Projection of the Nursing Fee Differentiation Policy Improvement Proposal in the National Health Insurance: Using a Break-even Analysis Model for the Optimal Nursing Fee (적정 간호인력 등급별 입원료 추정 모델을 이용한 간호관리료 차등제 정책개선 재정부담 추계)

  • Kim, Sungjae;Kim, Jinhyun
    • Journal of Korean Academy of Nursing Administration
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    • v.19 no.5
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    • pp.565-577
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    • 2013
  • Purpose: This study was done to propose an improvement in the Nursing Fee Differentiation Policy to alleviate polarization of nursing staffing level among hospitals and to rectify the confusion of legally mandated standards between the Korean Medical Law and National Health Insurance Act. Methods: The policy regulation was reconstructed related to nurse staffing standards and nurse-to-patients ratios. Data on nurse staffing grades were obtained from database of the Health Insurance Review & Assessment Service (HIRA) for the third quarter of 2010 for 44 tertiary hospitals, 274 general hospitals, and 1,262 hospitals. A break-even analysis was used to estimate financial burden of the revised policy improvement proposal. An industrial engineering method was used to calculate Nurse-to-Patients ratios per shift. Results: Twelve tertiary hospitals were downgraded. 74 general hospitals and 102 hospitals were upgraded after application of the regulation. Finances for total hospitalization expenditures changed from -3.55% to +3.14%. Conclusion: The results indicate that the proposed policy would decrease polarization between tertiary hospitals and small hospitals, and would not put a major strain on the finances of the Korean National Health Insurance. Therefore, it is suggested that government stake-holders and many interest groups consider this policy proposal and build a consensus.

Theoretical Studies of Hydrogen Bond Interactions in 4-Substituted Benzoic Acids Dimers (4-치환된 벤조산 2합체에서의 수소 결합 상호작용에 대한 이론적 연구)

  • Beni, Alireza Salimi;Chermahini, Alireza Najafi;Sharghi, Hashem
    • Journal of the Korean Chemical Society
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    • v.55 no.3
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    • pp.392-399
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    • 2011
  • Two conformations of benzoic acid derivatives ($NH_2$, OH, H, F, Cl, CN, NO, $NO_2$) have been investigated at MP2, DFT and HF level using the 6-311++G(d,p) basis set. It was found that the cis isomers are more stable. Hydrogen bonding formation of benzoic acids has been estimated from stabilization energies. The calculated hydrogen-bonding energies of dimers showed a cooperative interaction in the cyclic ones. It was found that an electron-releasing group (ERG) into the phenyl rings resulted in the formation of more stable hydrogen bonding. Red shift of O-H bond was found from -565.3 to -589.3 for dimers. The natural bond orbital (NBO) analysis was applied to characterize nature of the interaction.

A Study of Strategic Marketing Methods for Korean Shoes Industry to Make Inroad to EU Market (한국 신발산업의 대(對) EU시장 진출을 위한 전략적 마케팅 방안에 관한 연구)

  • Song Kyung-Soo;Kim Yong-Ho
    • Management & Information Systems Review
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    • v.17
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    • pp.215-242
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    • 2005
  • Although shoes industry in Korea is superior in global competition in terms of material, parts, and developmental ability, it has declined due to the lack of design in consideration of OEM production and marketing ability. Shoes industry in Korea has aimed at making inroad to North American market centered with the United States, but it has not focused on Europe market that much. However, as Europe transformed into EU, which is a large economic community, European market is being considered as a great potential for Korean shoes industry, which we can never neglect of. So far, there have been researches of marketing strategic methods to make inroad to the United States and South-East Asian markets, but there has been almost no marketing approach to European shoes market. Therefore, in this study I prepare strategic marketing plans for Korean shoes enterprises to make inroads to European markets, so that they can enter the market successfully, and this is the purpose of this study. In case that Korean shoes industry makes inroads to European market, there are important terms to examine. The strategic terms for consideration to examine are as follows. First, shoes companies such as Nike and Adidas are aware of India. Turkey, and Rumania as new footholds for production, as they have accounted continuous wage claim and labor dispute. Especially Turkey and Rumania are expected to have much competitive strength in price, as they are expected countries for joining EU. Second, we need to shift our understanding of the importance of design for European shoes market. We should pay close attention to the fact that the role of leading companies is to design. Third, Germany, England, and Italy have global-level of specialize institutions and organizations for shoes education and have been succeeded in knowledge industrialization. Fourth, we should consider that the concepts for shoes are changing from innovation in production to in products. Fifth, we should develop specialized concept centered in individualized categories. Sixth, we should open up new markets actively by connecting large shopping centers and multi-shops. Seventh, we should look for the opportunities to expand market through the utilization of BIFOS. Lastly, we should expand our support for opening up markets and participating fairs in foreign countries.

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