• 한국음향학회지
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• 제39권6호
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• pp.559-567
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• 2020

본 논문에서는 예인선배열에 수신되는 자함 소음을 제거하기 위한 소음 제거 기법을 제안한다. 자함 위치에 강인한 소음 기준 신호를 얻기 위하여 선배열의 일부 음향센서로 별도의 조향 빔을 형성한다. 이를 활용하여 Normalized Least Mean Square(NLMS) 적응 필터 기반의 주파수 영역 소음 제거 기법을 적용하였다. 생성한 기준신호와 입력 신호의 상관도를 이용하여 자함 소음 발생 방위를 산출하였으며, 해당 소음 방위로 입사된 소음의 빔패턴을 산출하였다. 소음 빔패턴을 이용해 자함 소음 준위를 추정하여 제거된 소음 성분이 추정 소음 준위를 초과하지 않도록 필터 갱신 여부를 결정함으로써 소음 제거 과정에서 표적신호가 소실되지 않도록 하였다. 모의신호를 이용한 실험을 통하여 동일한 방향에서 자함 기준 신호를 획득할 때 본 논문에서 제안한 기법이 기존 기법에 비해 자함 방위가 약 40 % 벗어나더라도 자함 소음 제거 성능이 유지됨을 확인하였으며, 자함 소음과 표적 소음의 주파수가 동일하게 수신될 경우에도 기존 기법과 달리 표적 신호를 탐지 가능함을 확인하였다.

• 방사성폐기물학회지
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• 제18권spc호
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• pp.75-87
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• 2020

The Korea Atomic Energy Research Institute (KAERI) has developed geological repository systems for the disposal of high-level wastes and spent nuclear fuels (SNFs) in South Korea. The purpose of the most recently developed system, the improved KAERI Reference Disposal System Plus (KRS⁺), is to dispose of all SNFs in Korea with improved disposal area efficiency. In this paper, a system-level safety assessment model for the KRS⁺ is presented with long-term assessment results. A system-level model is used to evaluate the overall performance of the disposal system rather than simulating a single component. Because a repository site in Korea has yet to be selected, a conceptual model is used to describe the proposed disposal system. Some uncertain parameters are incorporated into the model for the future site selection process. These parameters include options for a fractured pathway in a geosphere, parameters for radionuclide migration, and repository design dimensions. Two types of SNF, PULS7 from a pressurized water reactor and Canada Deuterium Uranium from a heavy water reactor, were selected as a reference inventory considering the future cumulative stock of SNFs in Korea. The highest peak radiological dose to a representative public was estimated to be 8.19×10^-4 mSv·yr^-1, primarily from ¹²⁹I. The proposed KRS⁺ design is expected to have a high safety margin that is on the order of two times lower than the dose limit criterion of 0.1 mSv·yr^-1.

• 보건교육건강증진학회지
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• 제31권4호
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• pp.1-10
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• 2014

Objectives: The effectiveness of Blood ${\beta}$-ketone testing by using self-monitoring strip on diabetic patients. Methods: Clinical effectiveness of blood ${\beta}$-ketone testing was assessed through correlation with reference test that measured blood ${\beta}$-ketone value through gas chromatography or enzyme method, diagnostic accuracy, time taken for the test and time taken for confirmative diagnosis of diabetic ketosis by selecting literatures on researches that conducted this test on ketosis(suspected) patients or diabetic ketosis(suspected) patients. Each of the stages from literature search to application of selection standards and extraction of data were carried out independently by the Subcommittee along with 2 researchers. Results: 7 reports were selected. ${\beta}$-ketone testing displayed high level of correlation in the range of r=0.92~0.99 with test using enzyme method as the reference standard. Regarding the diagnostic accuracy, sensitivity of 0.82, specificity of 0.74. The time taken for the test was 30seconds for the index test, which is shorter than reference standard test. Conclusion: Blood ${\beta}$-ketone testing was assessed to be a safe and effective test to monitor ketosis and assess the level of risk of ketosis by measuring the blood ${\beta}$-ketone on ketosis patients and diabetic ketosis patients since it has high level of correlation with reference test and short period of testing.

• 대한방사선기술학회지:방사선기술과학
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• 제46권2호
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• pp.123-129
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• 2023

Interventional cardiology procedures can involve relatively high radiation doses compared to conventional radiography. During CAG, CAG + PCI and PCI the same area is exposed to radiation for a long period. In this study, radiation exposure data of 421 examinations in Gyeongsang area were collected, and the DRLs and ADs in actual medical practice for three types of interventional cardiology procedures in Korea were established. In CAG 286 case, 75th percentile DRLs and ADs of the total DAP were 55.89 Gy·cm² and 37.47 Gy·cm² , respectively. In CAG + PCI 92 case, those values were 222.84 Gy·cm² and 117.51 Gy·cm² respectively. In PCI 43 case, those values were 198.73 Gy·cm² and 120.13 Gy·cm² respectively. In this study, for the first time, the diagnostic reference level of interventional cardiology procedures in Gyeongsang area were established. Using the diagnostic reference level of interventional cardiology procedures derived from this study, it will help to identify and improve the level of exposure dose in the region and country.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권11호
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• pp.2945-2965
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• 2023

The laser inertial measurement unit is a precision device widely used in rocket navigation system and other equipment, and its quality is directly related to navigation accuracy. In the quality evaluation of laser inertial measurement unit, there is inevitably uncertainty in the index input information. First, the input numerical information is in interval form. Second, the index input grade and the quality evaluation result grade are given according to different national standards. So, it is a key step to transform the interval information input by the index into the data form consistent with the evaluation result grade. In the case of uncertain input, this paper puts forward a method based on probability distribution to solve the problem of asymmetry between the reference grade given by the index and the evaluation result grade when evaluating the quality of laser inertial measurement unit. By mapping the numerical relationship between the designated reference level and the evaluation reference level of the index information under different distributions, the index evidence symmetrical with the evaluation reference level is given. After the uncertain input information is transformed into evidence of interval degree distribution by this method, the information fusion of interval degree distribution evidence is carried out by interval evidential reasoning algorithm, and the evaluation result is obtained by projection covariance matrix adaptive evolution strategy optimization. Taking a five-meter redundant laser inertial measurement unit as an example, the applicability and effectiveness of this method are verified.

• International Journal of Knowledge Content Development & Technology
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• 제8권2호
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• pp.49-65
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• 2018

Are the benefits derived from ICT based reference and information service worth the financial and other commitments devoted to it? In an attempt to answer this, this study delved into finding out the perceived benefits; the rational for ICT based reference services in Nigerian university libraries. The main objectives were to find out the purposes for using ICT facilities in reference services delivery and the perceived benefits derived from using ICT resources in reference and information services. Being a survey, questionnaire was used to collect data from the librarians of twelve (12) universities; two (2) each sampled from the six geopolitical zones of Nigeria. Data was analyzed using frequencies, mean scores and standard deviations. ANOVA statistical analysis was used to test the hypothesis of no significance difference in the benefits derived from ICT based reference services using p-value of 0.05 to calculate the level of significance. Findings showed that librarians and library users made use of ICT facilities for different reference purposes especially to obtain information they need using the internet. Other reference needs for which patrons used the ICT facilities included: - access to current e-books and e - journals, user education and access to global information in other libraries. Provision of current awareness services (CAS) and selective dissemination of information services (SDI), on-line searching using workstations in the library, provision of on-line public access catalogue (OPAC) services, keeping statistics of users of the reference section and compilation of bibliographies. Further findings showed that the librarians and library users derive a lot of benefits from their use of ICT facilities in reference services. The results showed that easy retrieval and dissemination of information to patrons were ranked highest by the librarians amongst others.

• Entomological Research
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• 제48권5호
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• pp.390-399
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• 2018

In order to precisely assess gene expression levels, the suitable internal reference genes must be served to quantify real-time reverse transcription polymerase chain reaction (RT-qPCR) data. For armyworm, Mythimna separata, which reference genes are suitable for assessing the level of transcriptional expression of target genes have yet to be explored. In this study, eight common reference genes, including ${\beta}$-actin (${\beta}$-ACT), 18 s ribosomal (18S), 28S ribosomal (28S), glyceraldehyde-3-phosphate (GAPDH), elongation fator-alpha ($EF1{\alpha}$), TATA box binding protein (TBP), ribosomal protein L7 (RPL7), and alpha-tubulin (${\alpha}$-TUB) that in different developmental stages, tissues and insecticide treatments of M. separata were evaluated. To further explore whether these genes were suitable to serve as endogenous controls, three software-based approaches (geNorm, BestKeeper, and NormFinder), the delta Ct method, and one web-based comprehensive tool (RefFinder) were employed to analyze and rank the tested genes. The optimal number of reference genes was determined using the geNorm program, and the suitability of particular reference genes was empirically validated according to normalized HSP70, and MsepCYP321A10 gene expression data. We found that the most suitable reference genes for the different experimental conditions. For developmental stages, 28S/RPL7 were the optimal reference genes, both $RPL7/EF1{\alpha}$ were suitable for experiments of different tissues, whereas for insecticide treatments, $28S/{\alpha}-TUB$ were suitable for normalizations of expression data. In addition, $28S/{\alpha}-TUB$ were the suitable reference genes because they have the most stable expression among different developmental stages, tissues and insecticide treatments. Our work is the first report on reference gene selection in M. separata, and might serve as a precedent for future gene expression studies.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
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• pp.1615-1618
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• 1987

시간 영역에서 만들어진 음성신호의 파라미터을 이용하여 주어진 음성신호의 구간이 유성음, 무성음, 혹은 묵음인지를 분류하는 새로운 알고리듬을 제시하였다. 이에 사용한 파라미터은 구간내에서 샘플링된 값의 절대치 합과 일정한 level 이상의 peak의 합(T-peak), T-peak와 절대치 합의 비 그리고, DPCM의 절대치 합들이다. 이를 파라미터를 이용하여 간단히 유성음/무성음/묵음 구간을 분류 할였다. This paper proposes new algorithm for classifying speech signal frame into voiced, unvoiced, silence frame, using the parameters extracted from time domain behavior of speech signal The parameters used in this paper are absolute magnitude, the sum of peaks lager than reference level (T-peak), the ratio of T-peak to absolute magnitude and the magnitude of signal outputs of DPCM. Using this parameters, speech signal is more easily classified into voiced/unvoiced/silence frame.

• Journal of Electrical Engineering and Technology
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• 제6권5호
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• pp.595-604
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• 2011

A three-phase three-level shunt active filter controlled by fuzzy logic current controller which can compensate current harmonics generated by nonlinear loads is presented. Three-level inverters and fuzzy controllers have been successfully employed in several power electronic applications these past years. To improve the conventional pwm controller performance, a new control scheme based on fuzzy current controller is adopted for three-level (NPC) shunt active filter. The scheme is designed to improve compensation capability of APF by adjusting the current error using a fuzzy rule. The inverter current reference signals required to compensate harmonic currents use the synchronous reference detection method. This technique is easy to implement and achieves good results. To maintain the dc voltage across capacitor constant and reduce inverter losses, a proportional integral voltage controller is used. The simulation of global system control and power circuits is performed using Matlab-Simulink and SimPowerSystem toolbox. The results obtained in transient and steady states under various operating conditions show the effectiveness of the proposed shunt active filter based on fuzzy current controller compared to the conventional scheme.

• Journal of the Korean Data and Information Science Society
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• 제19권4호
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• pp.1183-1189
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• 2008

The general formulas of the operating characteristic(OC) function, average sample number(ASN) and average outgoing quality(AOQ) for the modified n-level skip-lot sampling plan(MMSkSP2) were derived using Markov chain properties by Cho(2008). In this paper, the OC curve, ASN and AOQ of a reference plan, modified two-level, three-level and five-level skip-lot sampling plans are compared.