• Title/Summary/Keyword: reference level

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Improvement of Relative Positioning Accuracy with GPS Carrier Phase Using Multi-Base Station (다중기준국 방식을 이용한 GPS 반송파 상대측위 정확도 향상)

  • Lee, Jae-One
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.26 no.6
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    • pp.617-624
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    • 2008
  • In general, RTK-GPS(Real Time Kinematic GPS) based on the single reference station is able to determinate the high accurate position of rover on the spot using error correction information of transmitted carrier phase from the base station via wireless modem. However, single reference station method has some weak points to decrease positioning accuracy because it must be obtained carrier phase from the each satellite continuously, allowed to transmit without obstacle and limited to short base line distance between base and rover station. This paper aims to attempt network based GPS carrier phase differential positioning using three multi reference stations to overcome the method of single reference station and RTK network is realized by real time monitoring program with Visual C++. The optimum error correction value of three multi reference stations by RTK networking is selected automatically to correct the position of rover station. In this paper, this algorithm is applied to determine sea water level using GPS buoy, and the accuracy results of water level change were analyzed and compared with each other using single and multi reference stations.

On Reliability and Comparison of $J_{Rice}$-Resistance considering Optimal Strength Ratio and $J_{\delta}$-Resistance Curves converted from CTOD using Appropriate Strength chosen according to Strain Hardening Level (강도비를 적용한 Rice-저항곡선과 변형경화를 고려한 $J_{\delta}$-저항곡선과의 비교)

  • 장석기
    • Journal of Advanced Marine Engineering and Technology
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    • v.26 no.1
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    • pp.59-67
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    • 2002
  • The comparison of $J_{Rice}$-resistance considering a few strength ratio in Rice J-integral formula and $J_{\delta}$-resistance curves converted from experimental CTOD using appropriate strength chosen according to strain hardening level, n=10.6 (A533B steel) and n=8.1 (BS4360 steel) is carried out. The optimal dimensionless strength ratio like the factor of revision, (see full text)reflecting strain hardening level in Rice\`s experimental formula is found out and the reliability of appropriate reference strength chosen according to strain hardening level in different materials is investigated through doing that CTOD is transformed from $J_{\delta}$-integral using relationship between J-integral and CTOD. The results are as follows; 1) The optimal factor of revision is when m equals to 3 in (see full text) for Rice's and the above optimal factor of revision multiplies by coefficient, η in Rice's experimental formula instead of n=2, 2) and the pertinent reference strength for high strain hardening material like BS4360 steel is ultimate strength, $\sigma_{u}$ and for material like A533B steel is ultimate-flow strength, $\sigma_{u-f}$. The incompatible of the behavior of both experimental J-resistance curves using Rice's formula and CTOD-resistance curves for A533B and BS4360 steel by Gordon, et al., could be corrected using the optimal factor of revision in Rice\`s and the pertinent reference strength in J=$m_{j}$${\times}$$\sigma_{i}$${\times}$CTOD.

Evaluation of Diagnostic Reference Level in Interventional Procedures (인터벤션시술 진단참고수준 평가)

  • Kang, Byung-Sam;Park, Hyung-Shin
    • Journal of radiological science and technology
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    • v.44 no.5
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    • pp.451-457
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    • 2021
  • Recently, the number of interventional procedures has increased dramatically as an alternative of invasive surgical procedure and patient radiation exposure is also increasing accordingly. In this study, we evaluated the patient dose of major interventional procedures nationwide and we established our Korean database. With these results, we tried to suggest the reference dose level for major interventional procedures. We evaluated patent dose data in the field of interventional radiology from foreign countries. Measurement of radiation dose exposure for 11 major interventional procedures was conducted using embedded DAP meters in 10,006 patients from 47 hospitals, and reference level of each interventional procedure was suggested. The DRLs of each intervenional procedure are as follows: TACE 206(Gy·cm2), AVF 12(Gy·cm2), LE intervention 43(Gy·cm2), TFCA 122(Gy·cm2), Cerebral aneurysm coil embolization 214(Gy·cm2), PTBD 22(Gy·cm2), Biliary stent 60(Gy·cm2), PCN 7(Gy·cm2), Hickman catheter 2.1(Gy·cm2), Chemoport 1.4(Gy·cm2), BAE 104(Gy·cm2). Compared with the previously established DRL in 2012, the radiation dose decreased in all 10 interventional procedures. In the future, continuous publicity and education on the radiation dose reduction will be needed.

Information and referral service in public libraries (공공도서관의 정보 및 안내봉사 도입을 위한 연구)

  • 조명희;박준식
    • Journal of Korean Library and Information Science Society
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    • v.23
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    • pp.183-209
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    • 1995
  • The purpose of this study was to obtain the various basic data for introduction of information and referral service in the Korean public libraries. For the purpose, this study was conducted by carrying out theoretical research on the concept and definition of information and referral service, the type and level of the service and the needs for introduction of the service in public libraries and using questionnaires with 242 public libraries(reference librarians) all over the country, so as to examine the librarians' views on the whole service. The questionnaire mainly included questions about actual status, present level and understanding level of the service, reference librarians' response to needs for introduction of the service, and type and level of the service available when the service has been introduced. In conclusion, this study will help to establish basic foundation, so that the Korean public libraries can realize equalization of the service and promote the information and referral service.

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Korean Reference Disposal System for High-level Radioactive Wastes

  • Choi Heui-Joo;Choi Jongwon;Lee Jong Youl
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2005.11b
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    • pp.225-235
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    • 2005
  • This paper outlined the status of the development of Korean Reference Disposal (KRS­1) system for high-level radioactive wastes. The repository concept was based on the engineering barrier system which KAERI has developed through a long-term research and development program. The design requirements were prepared for the conceptual design of the repository. The amount of PWR and CANDU spent fuels were projected with the current nuclear power plan. The disposal rates of PWR and CANDU spent fuels were analyzed. The reference geologic characteristics including classification of fracture zones were set for the KRS. The disposal concepts and the layout of the repository were described.

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Korean-American Consumer Attitude Toward Luxury Fashion Products

  • Lee, Yoon-Jung;Lee, Jae-Il
    • International Journal of Human Ecology
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    • v.9 no.2
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    • pp.45-54
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    • 2008
  • This study examines the influence of acculturation level and ethnic groups as a fashion reference group on Korean-American consumer attitude toward luxury fashion brands. Of interest is the role of Korean culture, which emphasizes luxury brand consumption due to the Confucion value of 'face', on Korean-American attitudes toward luxury brands. Data were collected from 108 young Korean-Americans living in the Pacific Northwest of the United States. Descriptive statistics, factor analysis, and multiple regressions were conducted for the analysis. In general, the respondents had relatively negative attitudes toward luxury fashion brands. Even though the acculturation level did not have a significant influence, attitudes toward luxury fashion brands were influenced by Korean reference groups. Age at immigration did not have a significant relationship with attitudes toward luxury brands. Korean-Americans who maintain ties with Korean culture are more likely to have a positive attitude towards luxury fashion, regardless of familarity with American culture.

DC-Link Voltage Unbalance Compensation of Reactive Power Compensator using Multi-level Inverter (멀티레벨 인버터를 이용한 무효전력 보상장치에서의 DC-Link 전압 불평형 보상)

  • Kim, Hyo-Jin;Jung, Seung-Ki
    • The Transactions of the Korean Institute of Power Electronics
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    • v.18 no.5
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    • pp.422-428
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    • 2013
  • Recently, we use a static synchronous compensator(STATCOM) with cascaded H-bride topologies, because it is easy to increase capacity and to reduce total harmonic distortion(THD). When we use equipment for reactive power compensation, dc-link voltage unbalances occur from several reasons although loads are balanced. In the past, switching pattern change of single phase inverter and reference voltage magnitude change of inverter equipped with power sensor have been used for dc-link voltage balance. But previous methods are more complicated and expensive because of additional component costs. Therefore, this paper explains reasons of dc-link voltage unbalance and proposes solution. This solution is complex method that is composed of reference voltage magnitude change of inverter without additional hardware and shifted phase angle of inverter reference voltages change. It proves possibility through 1000[KVA] system simulation.

Communication Process in Reference/Information Service; Its Implication for Reference Teaching (정보 및 참고봉사상의 의사통신과정(意思通信過程) -참고과목을 위한 제언(提言)-)

  • Noh, Ock-Soon
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.2 no.1
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    • pp.66-87
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    • 1974
  • It is the prime importance of the information and the reference-librarians to better understand the communication functions of the library since they are the ones to whom the library users come first with their informational needs. Reference librarians often have the problem of providing information to those who may have little experience with, or interest in the library. There is also a problem of finding out what the person really wants, not what he says he wants. Therefore, the interaction between the librarian and the user involves a highly complex activity of communication with each other even before the actual search begins. Reference librarians cannot perform to any degree of success without comprehension of the general patterns and processes of communication in information seeking. Nonverbal as well as verbal transmittal process on the part of both librarians and patrons should not be overlooked. Some of the difficulties and barriers of library communication are brought so that possible cures and improvement may be sought. The basic purpose of the reference interview through which this interpersonal communication takes place is for the reference specialist to enable to link the needs of the patron with potential resource of the library. The writer firmly believes that this importance of the process be taught as well as the materials in reference service regardless of the level of the course offered in library science department.

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Serum Alpha-Fetoprotein Levels in Health Checkup Adults (건강 검진자들의 혈청 Alpha-Fetoprotein 농도)

  • Kim, Yoohyun
    • Korean Journal of Clinical Laboratory Science
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    • v.40 no.2
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    • pp.86-93
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    • 2008
  • This study was performed to investigation of the serum alpha-fetoprotein (AFP) levels in healthy adults. A total of 2,160 (male 1,415, female 745) health checkup adults were examined for AFP levels by chemiluminescence immunoassay (CLIA) method, during the period from September, 2007 to August, 2008. The mean serum AFP level was 2.168 (0.605~20.35) ng/mL, and it was 2.309 (0.605~20.35) ng/mL in male, 1.906 (0.605~10.36) ng/mL in female, respectively. 1,816 (male 1,109, female 709) healthy adults were screened for the absence of viral hepatitis and normal alanine amino transferase (ALT) levels. The mean serum AFP level of healthy adult was 2.041 (0.605~7.83) ng/mL, and it was 2.181 (0.605~7.83) ng/mL in male, 1.822 (0.605~6.55) ng/mL in female, respectively. Serum AFP increased with age group, there was a higher level in male compared to female. These results suggests that the use of reference value of AFP in healthy adults in the Jeonbuk. With the reference value now defined, it becomes possible to compare levels in different populations.

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Dietary Reference Intake of n-3 polyunsaturated fatty acids for Koreans

  • Park, Yongsoon
    • Nutrition Research and Practice
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    • v.16 no.sup1
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    • pp.47-56
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    • 2022
  • This paper examines the process and evidence used to create the Dietary Reference Intake (DRI) of alpha-linolenic acid (ALA) and eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) for Koreans. ALA (18:3n3) is an essential fatty acid, and EPA and DHA are known to have beneficial effects on cardiovascular disease risk and reduction of triglyceride levels. Various international organizations have suggested dietary recommendations for n-3 polyunsaturated fatty acids (PUFAs), including ALA, EPA, and DHA. A DRI for Koreans was established for the first time in 2020, specifically for the adequate intake (AI) of ALA and EPA + DHA. This recommendation was based on the average intake of ALA and EPA + DHA from the Korea National Health and Nutrition Examination Survey 2013-2017. For Korean infants, the AI of ALA and DHA was based on the fatty acid composition of maternal milk. Estimated average requirement and a tolerable upper intake level have not been set for n-3 PUFA due to insufficient evidence. In addition, the intake level of n-3 PUFA for prevention of chronic disease has also not been determined. Future studies and randomized controlled trials are required to establish the UL and to define the level for disease prevention.