• 한국음향학회지
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• 제19권8호
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• pp.63-67
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• 2000

본 논문에서는 화자인식의 성능향상을 위한 dynamic time warping (DTW) 기반의 문맥 제시형 화자인식에 대해 연구하였다. 화자인식에 있어 중요한 요소인 화자의 특성을 잘 반영할 수 있는 참조패턴을 생성하기 위해 유전자 알고리즘을 적용하였다. 또한, 문맥 종속형과 문맥 독립형 화자인식의 단점을 개선하기 위해 문맥 제시형 화자인식을 수행하였다. Clos set에서 화자식별과 open set에서 화자확인 실험을 하였으며 실험결과 기존 방법의 참조패턴을 이용하였을 경우보다 유전자 알고리즘에 의한 참조패턴이 인식률과 인식속도 면에서 우수함을 보였다.

• 대한의용생체공학회:의공학회지
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• 제28권5호
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• pp.665-675
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• 2007

The morphological change of ECG is the important diagnostic parameter to finding the malfunction of a heart. Generally ST segment deviation is concerned with myocardial abnormality. The aim of this study is to detect the change of ST in shape using a polynomial approximation method and the reference ST type. The developed algorithm consists of feature point detection, ST level detection and ST shape classification. The detection of QRS complex is accomplished using it's the morphological characteristics such as the steep slope and high amplitude. The developed algorithm detects the ST level change, and then classifies the ST shape type using the polynomial approximation. The algorithm finds the least squares curve for the data between S wave and T wave in ECG. This curve is used for the classification of the ST shapes. ST type is classified by comparing the slopes of the specified points between the reference ST set and the least square curve. Through the result from the developed algorithm, we can know when the ST level change occurs and what the ST shape type is.

• 기술혁신학회지
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• 제14권spc호
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• pp.1187-1208
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• 2011

본 연구는 기업의 보유자원(역량) 기반 관점에서 기업이 필요로 하는 유망기술 도출 모형을 제시하고자 하였다. 이를 위해서 첫째, 중소기업과 유망기술에 대한 고찰을 통해 중소기업이 필요로 하는 유망기술에 대해 개념적으로 정의하였다. 둘째로, 연구의 개념적 틀을 제시하고 X사의 사례 분석을 통하여 제시된 연구의 틀에 대한 유용성을 검증하였다. 기업이 진입해 있는 기술, 용도, 제품분야 키워드를 기준으로 기업의 진입영역을 대리하는 참조특허집합(reference patent set)을 구성하였다. 분석데이터는 참조특허집합을 두 단계까지 전방인용(forward citation)한 특허로 대상을 확장하여 구성하였다. 분석특허 풀에서 전문가가 선정한 키워드를 기준으로 클러스터 분석을 수행하고 클러스터의 활동성, 참조특허집합과의 관련성 지표를 기준으로 군집별 유망성을 분류하였다. 마지막으로 기업이 접근 가능한 영역에 대한 잠재 포트폴리오를 표현하고 기업이 단계적으로 접근가능한 유망영역, 모니터링 대상, 모니터링 제외대상 영역을 도출하였다.

• 핵의학기술
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• 제27권1호
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• pp.42-46
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• 2023

Purpose The reference range described in Adrenocorticotropic Hormone reagent used in our laboratory is 10-60 pg/mL at 8 a.m. to 10 a.m., and 6-30 pg/mL at 8 p.m. to 10 p.m. However, in the case of outpatients, blood is mainly collected between 10 a.m. and 6 p.m., accounting for 57.8% of the total. Therefore, This study is intended to help make a more accurate diagnosis by reevaluating the reference range provided by the manufacturer of the Adrenocorticotropic Hormone reagent and setting split-timed reference range. Materials and Methods The patients collected blood before 10 a.m. were group A (68 people), and the patients collected blood after 10 a.m. were set to group B (80 people). A T-test was performed between groups to test their significance. And it was confirmed whether it was necessary to set the gender classification as a subgroup. The method of setting the reference range was calculated by the Bayesian's method and the Hoffmann's method. Results The reference range of Group A was 8.6 to 60.6 pg/mL by the Bayesian's method, and the Hoffmann's method was 3.6 to 61.3 pg/mL. The reference range of Group B was 6.9 to 50.5 pg/mL when applying the Bayesian's method, and the Hoffmann method's was 2.3 to 48.9 pg/mL. Conclusion This study was concluded that it was necessary to set the split-timed reference range. Through this study, the later the blood collection time, the lower the level of Adrenocorticotropic Hormone, indicating that blood collection time is important for patients with clinical significance. If a large number of subjects are selected and supplemented in the future, it is believed that systematic and accurate reference range can be set.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(1)
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• pp.279-282
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• 2002

Here we introduce so called Reference code-weighted sum of all PN codes used in the system-. We do inner product operation between received PN code and Reference code rather than locally generated PN code in the receiver. Acquisition process can be accomplished by only one inner product during full period of PN code. It's essential innovation against present method which can be viewed successive hypothesis test by inner product for entire candidate PH codes set. Well -defined decision region makes it possible. We suggest the. criterion fur designing the decision region and find a condition for weight (coefficient) of Reference code.

• 핵의학기술
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• 제19권2호
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• pp.108-111
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• 2015

Purpose Lately, in accordance with the increasing interest about Healthcare accreditation program and International laboratory accreditation scheme, requirements about the instrument quality management are gradually taking shape. In nuclear medicine In vitro laboratory, the most typical instruments are multi detector gamma counter and automatic dispensing system. Each laboratory continue with the quality control adequate for circumstances. The purpose of this study is to application and establish the new Calibrator[I-125]Set which is efficient at standardization of equipment quality management. Materials and Methods Deviation between detectors were measured with 12 solid samples of the Calibrator[I-125]Set. their activities differ from each other by less than 1%. Multi detector gamma counters are GAMMA-10;Shinjin medics. Inc, Goyansi, Korea(Gamma counter A), SR300;Stratec biomedical systems AG, Gewerbestr, Germany(Gamma counter B) and COBRA II; Packard Instrument Co. Inc, Meriden, USA(Gamma counter C). Evaluation of two automatic dispensing system used A, B liquid tracer of the Calibrator[I-125]Set. After dispensing and counting, calculated using the ratio of the measured value and proposed value. We used solution A for 20, 25ul and solution B for 50, 100ul. Method of data analysis and reference range was provided by kit documentation. Furthermore, we could calculate our counter efficiency indirectly. Results The CV(%) of measured values by Gamma counter A, B, C are 0.34, 0.70, 1.30. Calculated value are 1.05314, 2.10419, 4.08485. Provided reference range is less than 3. A dispensing system's calculated values are 0.986, 0.989, 1.023, 1.017 and B are 0.874, 0.725, 1.021, 0.904. Provided reference range is from 0.95 to 1.05. Also, counter's efficiency are 74.18, 72.79, 74.32% at counter A, B, C and efficiency of the one detector counter is 79.26%. Conclusion If using this Calibrator[I-125]Set after verifying whether quality assurance, is applicable to equipment quality management on behalf of the role of gold standard.

• 제어로봇시스템학회논문지
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• 제19권3호
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• pp.177-182
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• 2013

This paper proposes an input-constrained reference tracking control of a converter model. To this end, first it is shown that the bilinear converter model can be equivalently represented by a linear uncertain model belonging to a polytopic set. Then, an input-constrained tracking control scheme for the linear uncertain model is designed based on recently proposed tracking control scheme. The control scheme yields not only a stabilizing control gain but also a feasible and invariant set for the converter model. Finally, simulation results show that the state trajectory always stays in the feasible and invariant set and that the output tracks the given reference while satisfying the input constraint.

• Journal of Power Electronics
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• 제19권1호
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• pp.168-178
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• 2019

Discrete space vector modulation (DSVM) is an effective method to improve the steady-state performance of the finite control set predictive control for permanent magnet synchronous motor drive systems. However, it requires complex computations due to the presence of numerous virtual voltage vectors. This paper proposes an improved finite control set model-free predictive control using DSVM to reduce the computational burden. First, model-free deadbeat current control is used to generate the reference voltage vector. Then, based on the principle that the voltage vector closest to the reference voltage vector minimizes the cost function, the optimal voltage vector is obtained in an effective way which avoids evaluation of the cost function. Additionally, in order to implement double-objective control, a two-level decisional cost function is designed to sequentially reduce the stator currents tracking error and the inverter switching frequency. The effectiveness of the proposed control is validated based on experimental tests.

• 대한의용생체공학회:의공학회지
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• 제32권2호
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• pp.134-143
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• 2011

The selection of meaningful clinical tests and its reference values from a high-dimensional clinical data with imbalanced class distribution, one class is represented by a large number of examples while the other is represented by only a few, is an important issue for differential diagnosis between similar diseases, but difficult. For this purpose, this study introduces methods based on the concepts of both discernibility matrix and function in rough set theory (RST) with two discretization approaches, equal width and frequency discretization. Here these discretization approaches are used to define the reference values for clinical tests, and the discernibility matrix and function are used to extract a subset of significant clinical tests from the translated nominal attribute values. To show its applicability in the differential diagnosis problem, we have applied it to extract the significant clinical tests and its reference values between normal (N = 351) and abnormal group (N = 101) with either cholecystitis or cholelithiasis disease. In addition, we investigated not only the selected significant clinical tests and the variations of its reference values, but also the average predictive accuracies on four evaluation criteria, i.e., accuracy, sensitivity, specificity, and geometric mean, during l0-fold cross validation. From the experimental results, we confirmed that two discretization approaches based rough set approximation methods with relative frequency give better results than those with absolute frequency, in the evaluation criteria (i.e., average geometric mean). Thus it shows that the prediction model using relative frequency can be used effectively in classification and prediction problems of the clinical data with imbalanced class distribution.

• 한국산업보건학회지
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• 제26권2호
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• pp.109-118
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• 2016

Objectives: To review reference levels by the international and domestic management and provide the basis for setting occupational exposure limits(OELs) of radon in Korea Methods: Government's organizations with laws and systems for monitoring radon exposure were investigated and compared. There are five laws governing Indoor Air Quality(IAQ) control such as Occupational Safety and Health Act, Indoor Air Quality Control in Public Use Facilities, Etc. Act, School Health Act, Public Health Control Act and Parking Lot Act in Korea. It was surveyed that a total of 32 countries including 24 countries in the European Union(EU), six countries in Asian and two countries in North America setting the reference levels for radon in the world. Results: In Korea, there are set guidelines for radon in the Ministry of Environment and the Ministry of Education. Reference levels of radon for existing dwellings were $150{\sim}400Bq/m^3$ for Western European countries, and $200{\sim}1,500Bq/m^3$ in Eastern European countries. Approximately 67% of those EU countries were set up $400Bq/m^3$ to the standards for existing dwellings. EU countries such as Luxembourg, Finland, Norway, Sweden and Russia had adopted mandatory level for radon. Radon guidelines for new dwellings were set more strictly reference level($200Bq/m^3$) than existing dwellings. Conclusions: International organizations such as ICRP, UNSCEAR and NCRP, etc. had recommended the guidelines for radon. It was calculated the relation of the dose conversion factors with the annual effective doses. the OELs of radon suggest to need to establish $150Bq/m^3$ for office room and $400{\sim}1,000Bq/m^3$ for the workplace.