• 전기학회논문지P
• /
• 제63권4호
• /
• pp.317-321
• /
• 2014

This paper describes the information for quantitative simulation of weakly ionized plasma. We must grasp the meaning of the plasma state condition to utilize engineering application and to understand materials of plasma state. Using quantitative simulations of weakly ionized plasma, we can analyze gas characteristic. In this paper, the electron Ionization and diffusion Coefficients in $CH_4$ has been analysed over the E/N range 0.1~300[Td], at the 300[$^{\circ}K$] by the two term approximation Boltzmann equation method and Monte Carlo Simulation. Boltzmann equation method has also been used to predict swarm parameter using the same cross sections as input. The behavior of electron has been calculated to give swarm parameter for the electron energy distribution function has been analysed in $CH_4$ at E/N=10, 100 for a case of the equilibrium region in the mean energy. A set of electron collision cross section has been assembled and used in Monte Carlo simulation to predict values of swarm parameters. The result of Boltzmann equation and Monte Carlo Simulation has been compared with experimental data by Ohmori, Lucas and Carter. The swarm parameter from the swarm study are expected to sever as a critical test of current theories of low energy scattering by atoms and molecules.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2000년도 하계학술대회 논문집 C
• /
• pp.1850-1852
• /
• 2000

In this paper, new Partial Discharge (PD) detection technique using Pockels cell was proposed and considerable apparent chaotic characteristics were discussed. For this purpose, PD was generated from needle-plane electrode in air and detected by optical measuring system using Pockels cell, based on Mach-Zehnder interferometer, consisting of He-Ne laser, single mode optical fiber, 50/50 beam splitter and photo detector. A qualitative analysis was carried out by drawing Return map for the normalized time series of the detected PD signals. The results are as follows:(a) Fixed points, between 0.7 and 1.0, are appeared clearly in the right upper area of the return map as the increase in the number of obtained data.(b) Considerable periodicity have been remarked even though exact period and length can not be determined.(c) The self-similarity can be also observed inasmuch as the late paths do not follow the previous ones. Accordingly, exact quantitative analysis such as embedding dimension, fractal dimension, and Lyapunov exponents should be carried out for deducing the quantitative properties regarding PD phenomena.

• 한국실내디자인학회논문집
• /
• 제29호
• /
• pp.86-93
• /
• 2001

This study presents about the method of alternatives selection by considering wall performance and interior design. Wall is selected fur the object and 3 items of cost, performance, and design as the objective function for optimizing are determined. Thus the wall performance selected problems, which are improvement of insulation performance, sweaty prevention, sound insulation performance and design selected problems, which is satisfactory Improvement of users about Interior design. It is important to select alternatives that can satisfy the performance and design on the capital given as much as possible. But quantitative problem such as performance or expanses and qualitative problem such as design are not in the same dimension. Therefore this problem is a multi-criteria optimization problem and also has used AHP method as the method to solve these. Moreover GA is used to solve a problem of the alternatives occurrence, which is the characteristic of multi-criteria problem. This study presents the solution method on multi-criteria problem that has been mix loaded of quantitative problem and qualitative problem by using AHP(Analytic Hierarchy Process) and GA(Genetic Algorithm).

• 한국정보처리학회논문지
• /
• 제6권10호
• /
• pp.2597-2607
• /
• 1999

본 논문은 기존의 수량적 연관규칙탐사를 위한 고빈도항목열 생성방법이 가지고 있는 문제점을 해결하는 효율적인 고빈도항목열 생성기법을 제안한다. 제안된 생성기법은 분할과정에서 최소분할지지율을 이용하여 분할간격을 유동적으로 결정하는 방법과 데이타의 집중도를 우선 순위로 하여 분할된 소간격을 병합하는 방법을 사용한다. 본 논문에서 제안한 방법은 기존의 방법보다 세밀한 고빈도항목열을 생성할 수 있는 것과 데이타들의 특성을 잃어버리지 않는 특징을 갖는다. 성능평가를 통하여 제안된 방법이 기존의 방법에 비해 보다 효율적인 고빈도항목열을 생성함을 보인다.

• 센서학회지
• /
• 제13권1호
• /
• pp.47-55
• /
• 2004

This paper presents drug release properties of active drug delivery system (DDS) using volume change of polypyrrole (PPy). The incorporation of various chemical substances into the PPy and controlling its release with the externally applied voltage to the PPy are possible. In order to confirm possibility for drug delivery system qualitatively, indicator(phenol red) was examined as a dopant of PPy. The applied voltage to the PPy electrode was set to -2 V and this negative voltage makes the anionic indicator released in saline solution. After qualitative analysis, in order to confirm quantitative drug release characteristic of PPy, salicylate which is one of the aspirin substance was used as a dopant of PPy. As a result, the salicylate release characteristics with time was thoroughly investigated while varying the electrode area, polymerization time, the applied voltage for drug release. Based on these quantitative results, a preliminary experiment was carried out to check the feasibility of the PPy applicable to the neuronal system.

• Natural Product Sciences
• /
• 제28권4호
• /
• pp.181-186
• /
• 2022

A germacrane-type sesquiterpenoid was isolated and purified from a methanol extract of the roots of Valeriana fauriei (RVF) through open column chromatography using silica gel. This compound was verified to be heishuixiecaoline A by spectroscopic analysis. This compound was isolated for the first time from RVF. Quantitative analysis of heishuixiecaoline A from RVF cultivated from three different regions (Eumseong, Jinbu, and Jinan regions) was performed by combining high-performance liquid chromatography with a photodiode array detector. The extract of RVF cultivated in the Jinbu region showed the highest content (9.23 mg/g). In addition, a significant amount of the compound was detected in all RVF samples, which could be expected since it is a characteristic compound of RVF. The sesquiterpenoid group heishuixiecaoline A was isolated from RVF, a resource for various pharmacological substances, and quantitative analysis of RVF cultivated from three different regions was performed. As a result of these experiments, basic data on RVF that can be used in the development and application of pharmaceuticals and health functional foods in the future were obtained.

• Journal of Microbiology and Biotechnology
• /
• 제24권8호
• /
• pp.1044-1050
• /
• 2014

Since there is no consensus about the most reliable assays to detect invasive aspergillosis from samples obtained by minimally invasive or noninvasive methods, we compared the efficacy of an enzyme-linked immunosorbent assay (ELISA) for galactomannan (GM) detection and quantitative real-time PCR assay (qRT-PCR) for the diagnosis of invasive pulmonary aspergillosis. Neutropenic, male Sprague-Dawley rats (specific pathogen free; 8 weeks old; weight, $200{\pm}20g$) were immunosuppressed with cyclophosphamide and infected with Aspergillus fumigatus intratracheally. Tissue and whole blood samples were harvested on days 1, 3, 5, and 7 post-infection and examined with GM ELISA and qRT-PCR. The A. fumigatus DNA detection sequence was detected in the following number of samples from 12 immunosuppressed, infected rats examined on the scheduled days: day 1 (0/12), day 3 (0/12), day 5 (6/12), and day 7 (8/12) post-infection. The sensitivity and specificity of the qRT-PCR assay was 29.2% and 100%, respectively. Receiver operating characteristic curve (ROC) analysis indicated a Ct (cycle threshold) cut-off value of 15.35, and the area under the curve (AUC) was 0.627. The GM assay detected antigen in sera obtained on day 1 (5/12), day 3 (9/12), day 5 (12/12), and day 7 (12/12) post-infection, and thus had a sensitivity of 79.2% and a specificity of 100%. The ROC of the GM assay indicated that the optimal Ct cut-off value was 1.40 (AUC, 0.919). The GM assay was more sensitive than the qRT-PCR assay in diagnosing invasive pulmonary aspergillosis in rats.

• 한국방사선학회논문지
• /
• 제6권5호
• /
• pp.351-356
• /
• 2012

초음파 캐비테이션 현상이란 강한 초음파 조사 조건에서 매질(주로 유체) 내에서 미세기포를 발생시키고, 천이시키는 물리적 현상을 의미한다. 본 연구에서는 초음파 캐비테이션 발생량의 정량적 평가를 위하여 초음파 조사조건에 따른 기포군의 초음파 음향 특성변화를 관찰하였다. 중심 주파수가 500 kHz. 1.1 MHz인 곡면형 단일 초음파 변환기를 이용하여 캐비테이션 현상을 발생시켰으며, 형성되는 기포군을 가로지르는 2.25 MHz 간섭 초음파를 송/수신하여 분석하였다. 본 연구에서는 캐비테이션 발생량 평가를 위한 파라미터로 투과하는 파의 중심주파수 변화 및 감쇠 특성, 전파시간을 제시하였으며, 캐비테이션 발생 조건(조사 강도 및 여기 신호, 중심주파수)에 따른 변화를 관찰하였다. 획득된 간섭 초음파 수신신호를 분석한 결과, 중심 주파수의 변화의 경우 상관계수는 낮지만 조사 강도에 따른 상관관계를 확인할 수 있었으며, 특정 조사 조건에서 주목할 만한 급격한 중심 주파수 변화가 관찰되었다. 조사조건에 따른 간섭 초음파의 감쇠 추세는 모든 조건에서 높은 상관관계를 보였으며, 캐비테이션 발생형태에 영향을 받지 않는 것으로 확인되었다. 조사조건에 따른 전파 시간의 변화는 관찰되지 않았다. 차후 다양한 조사조건에 대한 평가를 통하여 보다 정량적인 캐비테이션 발생량 평가가 가능할 것으로 판단되며, 이러한 정량적 평가는 고강도 초음파 치료에서 발생할 수 있는 현상에 대한 기초 연구로서 활용 가능할 것으로 사료된다.

• 대한교통학회지
• /
• 제29권6호
• /
• pp.85-93
• /
• 2011

보도 폭은 보행자들의 쾌적한 통행 환경 조성에 중요한 요인 중 하나이다. 보도 폭을 결정하는 절차는 도로용량 편람에 제시된 서비스수준을 이용하여 정하는 방법이 제시되어 있다. 그러나 편람은 도시 가로상 보도와 지하철역내 보행자도로를 구분하지 않고 서비스수준을 제시하고 있어, 두 환경에서 보행자 이동 특성의 차이를 반영하기 어렵다. 지하철 역내 통로에서는 자동차 교통류와 유사하게 종방향으로 보행자 군을 형성하는 경우가 빈번하지만 도시 가로에서는 매우 드물게 관찰되는 특수한 상황이기 때문이다. 따라서 도시 가로상 보도의 고유 특성을 반영하기 위해서는 보도 서비스수준에 방법상의 변화가 필요하다. 본고는 새로운 보도 서비스수준 평가방안을 검토하고, 보도 폭 설계에 활용될 수 있는 근거를 마련하기 위해 옥외실험을 실시하였다. 특히 본 논문에서는 새로운 서비스수준 척도를 정량적으로 평가하기 위해 GPS를 이용하였고, 정량적 평가와 정성적인 평가결과를 비교적으로 분석하였다.

• Journal of Preventive Medicine and Public Health
• /
• 제34권4호
• /
• pp.408-416
• /
• 2001

Objectives : To evaluate the diagnostic value of quantitative ultrasound (QUS) in the prediction of osteoporosis as defined by dual energy x-ray absorptiometry (DEXA) in postmenopausal women. Methods : Questionnaires and height and weight measurements were used in the investigation of 176 postmenopausal women. QUS measurements were taken on the right calcaneus while bone mineral density (BMD) measurements of the lumbar spine and femoral neck were made with DEXA. The areas under the curves (AUC) of the speed of sound (SOS) for osteoporosis in the lumbar spine and femoral neck were obtained through receiver operating characteristic (ROC) analysis and evaluated. A comparison was made, for osteoporosis in the lumbar spine and femoral neck, between the AUCs of the logistic model with clinical risk factors and SOS. Results : Pearson's correlation coefficients of SOS and lumbar spine BMD, and of SOS and femoral neck BMD were 0.26 and 0.37. The AUC for the logistic model in its discrimination for lumbar spine osteoporosis was 0.764, and for SOS 0.605. The AUCs for the logistic model in its discrimination for femoral neck osteoporosis and for SOS were 0.890 and 0.892, respectively. Conclusions : These results suggest that the diagnostic value of QUS as a screening tool for osteoporosis is moderate for the femoral neck, but merely low for the lumbar spine and that the predictability provided by SOS is no better than that by the sole use of clinical risk factors in postmenopausal women.