• 한국환경복원기술학회지
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• 제27권2호
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• pp.29-42
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• 2024

As a global response to climate and biodiversity challenges, there is an emphasis on the conservation and restoration of ecosystems that can simultaneously reduce carbon emissions and enhance biodiversity. This study comprised a text analysis and keyword extraction of 1,100 research papers addressing nature restoration in Korea, aiming to provide a quantative and systematic evaluation of domestic research trends in this field. To discern the major research topics of these papers, topic modeling was applied and correlations were established through network analysis. Research on nature restoration exhibited a mainly upward trend in 2002-2022 but with a slight recent decline. The most common keywords were "species," "forest," and "water". Research topics were broadly classified into (1) predictions of habitat size and species distribution, (2) the conservation and utilization of natural resources in urban areas, (3) ecosystems and landscape managements in protected areas, (4) the planting and growth of vegetation, and (5) habitat formation methods. The number of studies on nature restoration are increasing across various domains in Korea, with each domain experiencing professional development.

• 한국정보통신학회논문지
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• 제7권2호
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• pp.201-207
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• 2003

일반적으로 블루투스 기술은 기기들이 한의 중심기기에 7개의 보조기기가 연결된 소형 네트워크를 피코넷 구성하게 하는 통신규약을 의미한다. 스캐터넷은 피코넷과 피코넷 간의 통신으로 이루어져 있다. 스캐터넷의 형태로는 트리와 링 형태가 있다. 그리고 링 형태가 모바일 환경에 더욱 적합하다고 한다. 본 노문은 트리와 링 구조의 성능을 비교 분석하여 어떤 형태가 모바일 환경에 적합한지를 알아보았다. 성능 측정은 단말기들이 빈번하게 추가 삭제되는 모바일 환경에서 스캐터넷 형성 알고리즘을 분석하여 스캐터넷 형성시간을 비교하였다. 실험 결과는 노드 수의 증가에 따라 트리 구조보다는 링 구조가 스캐터넷 형성 시간이 빠르고 시간의 차이의 폭이 넓어졌다.

• Tribology and Lubricants
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• 제28권3호
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• pp.124-129
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• 2012

The prediction of fretting wear is a significant issue for the design of contacting mechanical components such as flexible couplings and splines, jointed structures and so on. In our earlier study, we developed a numerical model to predict the fretting wear using boundary element method. The developed algorithm needs experimental fretting wear coefficients and friction coefficients between two moving materials to get more reliable results. In this study, therefore, we demonstrated the measurement method of the fretting wear coefficients and friction coefficients using disk on plate tribometer with piazo actuator and gap sensor. For four different material combinations, the fretting wear coefficients and friction coefficients are acquired through the fretting wear experiment and the analysis of the measured values. Thess results are useful to predict the quantative fretting wear rate in the developed algorithm.

• Environmental Analysis Health and Toxicology
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• 제9권1_2호
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• pp.19-23
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• 1994

The tetrazolium dye, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), is reduced by live but not dead cell, and this reaction is used as the end point in a rapid drug screening assay. It can also be used for accurate determinations of drug sensitivity but only if a quantative relationship is established between cell number and MTT-formazan production. Several conditions were examined to devise an in vitro assay method in primary cultured hepatocytes, such as optimum wavelength, optimal MTT concentration, optimal incubation time, and cell density.

• 한국농공학회논문집
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• 제47권2호
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• pp.25-32
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• 2005

In evaluation of public works, its components related with benefit and cost in feasibility analysis can be classified to quantative and qualitative elements, To evaluate qualitative components which can not be calculated by numerical value, several methods are used to assess relative importance. AHP (Analytic Hierarchy Process) is representative method which can evaluate importance, but it has difficulties in organization of expert group, execution of question, and subjective decision of questioner. Information measure technique can be used to evaluate these qualitative importance of environmental and social components in public works planning. In result of comparing importances of AHP and information measure technique, it has statistical significance in of road project.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.778-784
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• 2002

FFU are used increasingly by the microeleceronics industry to provide clean recirculating air for the fabrication of integrated circuits and laminar flow air. There may be several hundred ffu in a large cleanroom, covering 100% of the ceiling area. Hence, there is of often knowledge in the inside and outside of the country the flu give rise to noise & vibration trouble to microelectronics industry. Noise ＆ Vibration control for satisfication about noise ＆ vibration criteria in TFT-LCD factory cleanroom be in need of exact noise & vibration data of accurence from utility & equipment that can be exert a bad influence upon cleanroom. In this pater, hence we found out noise and vibration properities of ffu by using experimental method. And, we performed noise ＆ vibration analysis about noise it vibration level in cleanroom using semiempirical method for quantative approach about noise ＆ vibration level in cleanroom.

• Journal of Biosystems Engineering
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• 제17권1호
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• pp.5-17
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• 1992

To develop an analytic method of combustion characteristics in a small sized and single cylinder type diesel engine for a power tiller, 1) the theoritical analysis of combustion gas in engine cylinder was performed based on thermoscience and 2) the computer program which could be used to calculate those values of the apparent burning rate, the heat loss, the gas temperature and the fuel-air equivalence ratio with the experimental cylinder pressure data, was developed. This method would provide the practical and quantative data for the diesel combustion process. Through the use of this method, following details would be obtained: 1) the application in the modeling of combustion process without detail knowledeg of combustion process, 2) the basis for the complete modeling of diesel engine, and 3) the basic information for the design of combustion chamber by the prediction of engine performance.

• Biomolecules & Therapeutics
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• 제10권4호
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• pp.211-217
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• 2002

Hepatoprotective activity of methanol extract of Angelica tenuissima Nakai on the $CCl_4$-induced hepatotoxicity was investigated. To elucidate the hepatoprotective activity and free radical scavenging effect, we examined alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin, total protein, cholesterol, malondialdehyde (MDA) levels in serum and activities of superoxide dismutase (SOD), catalase (CAT) in hepatic tissue as compared with those of carbon tetrachloride-induced rats. The action mechanism also has been estimated by quantative analysis of cytochrome P450 (CYP), NADPH-CYP reductase for phase I metabolism and glutathion (GSH), glutathion S-transferase (GST) level for phase II metabolsim. Treatment of Angelica tenuissima methanol extract significantly lowered the levels of alanine aminotransferase and aspartate aminotransferase. In addition, the levels of cholesterol, triglyceride, MDA, CAT were decreased, and SOD was activated. This result indicates that the hepatoprotective effect of Angelica tenuissima methanol extract on the CCl4-induced hepatotoxicity would be originated from reduction of the NADPH-CYP reductase, GSH and the enhancement of the activities of GST, CYP.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1990년도 추계학술대회
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• pp.114-117
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• 1990

EEG signal is analyzed by two methods, analysis by visual inspection of EEG recording sheets and analysis by quantative method. Generally visual inspection method is used in the clinical field. But this method has its limitation because EEG signal is random signal. Therefore it is necessary to analyze EEG signals quantatively to obtain more precise and objective information of neural and brain. In this paper, power spectrum of EEG signal was estimated by AR(AutoRegressive) model in the frequency domain. This process is useful as a preprocessing stage for tomographic brain mapping (TBM) at each frequency, band. As a method for estimating power spectral density of EEG signals, periodogram method, autocorrelation method. covariance method, modified covariance method, and Burg method are tested in this paper.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1993년도 추계학술대회
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• pp.145-150
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• 1993

It is an important component of the diagnosis to research the morphological changes of EMG in pathological conditions. In order to provide an EMG signal resulting from a predetermined neuromuscular pathophysiology, we have initially developed a mathmatical model of electromyographic interference pattern(IP). It can be used to study the variation of the IP resulting from morphological and electrophysiological changes occurring in disease states, because the model computes the IP from the underlying fiber and muscle structure. We performed quantative analysis or the model output, focusing on IPs resulting from simulations of dystrophic fiber loss and the MU denervation and reinnervation typical of neuropathies. To discribe the characteristics of IPs associated with these pathologies, a set of frequency domain discriptors, activity, mobility, and complexity were used, as well as several measures of the spectral density function. These discriptors demonstrate distinct patterns of variation corresponding to morphological changes observed in disease states, and closely with results obtained from the classical method, turn/amp technique.