• 한국문헌정보학회지
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• 제6권
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• pp.87-103
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• 1979

Information storage and retrieval is a part of general communication process. In the Shannon's information theory, information contained in a message is a measure of -uncertainty about information source and the amount of information is measured by entropy. Indexing is a process of reducing entropy of information source since document collection is divided into many smaller groups according to the subjects documents deal with. Significant concepts contained in every document are mapped into the set of all sets of index terms. Thus index itself is formed by paired sets of index terms and documents. Without indexing the entropy of document collection consisting of N documents is $log_2\;N$, whereas the average entropy of smaller groups $(W_1,\;W_2,...W_m)$ is as small $(as\;(\sum\limits^m_{i=1}\;H(W_i))/m$. Retrieval efficiency is a measure of information system's performance, which is largely affected by goodness of index. If all and only documents evaluated relevant to user's query can be retrieved, the information system is said $100\%$ efficient. Document file W may be potentially classified into two sets of relevant documents and non-relevant documents to a specific query. After retrieval, the document file W' is reclassified into four sets of relevant-retrieved, relevant-not retrieved, non-relevant-retrieved and non-relevant-not retrieved. It is shown in the paper that the difference in two entropies of document file Wand document file W' is a proper measure of retrieval efficiency.

• 한국광학회지
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• 제6권4호
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• pp.282-287
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• 1995

발진 파장 영역이 매우 광범위한 티타늄 사파이어를 사용하여 접힌 공진기 형태의 레이저를 제작하고 연속 발진 특성을 조사하였다. 티타늄 사파이어 결정은 $Ti^{3+}$ 도핑율이 0.15wt.%이고 두께가 4.1mm이며 양면이 Brewster 각으로 되어 있는 것을 사용하였다. Brewster 면에서는 비점수차가 발생하므로 이를 보정하기 위하여 공진기의 접힌 각도를 $15.4^{\circ}$로 조정하였다. 펌핑 광원으로는 Ar-ion 레이저를 사용하였고, 반사율 90%의 출력경을 사용하여 2W 펌핑에서 레이저 발진이 시작되었으며, 5W 펌핑에서 450mW 이상의 츨력을 얻을 수 있었다. 또한 공진기의 두 오목거울 간의 거리에 따라 출력 변화를 조사하였다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제3권1호
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• pp.1-6
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• 2003

The Delayed Feedback Control method (DFC) proposed by Pyragas applies an input based on the difference between the current state of the system, which is generating chaos orbits, and the $\tau$-time delayed state, and stabilizes the chaos orbit into a target. In DFC, the information about a position in the state space is unnecessary if the period of the unstable periodic orbit to stabilize is known. There exists the fault that DFC cannot stabilize the unstable periodic orbit when a linearlized system around the periodic point has an odd number property. There is the chaos control method using the prediction of the $\tau$-time future state (PDFC) proposed by Ushio et al. as the method to compensate this fault. Then, we propose a method such as improving the fault of the DFC. Namely, we combine DFC and PDFC with parameter W, which indicates the balance of both methods, not to lose each advantage. Therefore, we stabilize the state into the $\tau$ periodic orbit, and ask for the ranges of Wand gain K using Jury' method, and determine the quasi-optimum pair of (W, K) using a genetic algorithm. Finally, we apply the proposed method to a discrete-time chaotic system, and show the efficiency through some examples of numerical experiments.

• Journal of Electrical Engineering and Technology
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• 제2권1호
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• pp.106-111
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• 2007

Laser cutting with the micro-control technique has great potential to be employed for acrylic machining. In this paper, the optimal conditions of acrylic etching have been investigated. The three parameters such as laser power, moving velocity, and thickness of acrylic are experimented to find out optimal conditions. From these experimental results, we have known that it is very important to control accurate power by the TRIAC switching technique. The best condition of acrylic etching is performed 10 Wand 72 mm/sec at the plastic thickness of 1.33 mm. The other case is performed 10 W and 48 mm/sec, and 12 W and 56 mm/sec at the acrylic thickness of 2.00mm, respectively.

• Journal of Microbiology and Biotechnology
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• 제32권6호
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• pp.768-775
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• 2022

In this study we aimed to derive the response surface models for Escherichia coli reduction in wheat flour using atmospheric cold plasma (ACP) with three types of gas. The jet-type atmospheric cold plasma wand system was used with a 30 W power supply, and three gases (argon, air, and nitrogen) were applied as the treatment gas. The operating parameters for process optimization considered were wheat flour mass (g), treatment time (min), and gas flow rate (L/min). The wheat flour samples were artificially contaminated with E. coli at a concentration of 9.25 ± 0.74 log CFU/g. ACP treatments with argon, air, and nitrogen resulted in 2.66, 4.21, and 5.55 log CFU/g reduction of E. coli, respectively, in wheat flour under optimized conditions. The optimized conditions to reduce E. coli were 0.5 g of the flour mass, 15 min of treatment time, and 0.20 L/min of nitrogen gas flow rate, and the predicted highest reduction level from modeling was 5.63 log CFU/g.

• Journal of Information Technology Applications and Management
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• 제18권4호
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• pp.95-118
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• 2011

In developing information systems, conceptual modeling is among the most fundamental means. The importance attributed to conceptual modeling has not only given rise to a lot of modeling methods, but also to the "yet another modeling approach (YAMA)" syndrome and the "not another modeling approach (NAMA)" hysteria. Criticism of conceptual modeling methods usually targets their lacking of theoretical foundations. In response to such criticism, various approaches towards theoretical foundations of conceptual modeling have been proposed so far. One of the recent responses to the quest for theoretical foundations of conceptual modeling is the reference to the philosophical ontology. The currently most prominent of diverse approaches towards ontological foundations of conceptual modeling appears to be the Bunge-Wand-Weber (BWW) ontology. Recent approaches attempt to regard BWW ontology as another conceptual data model as well as a criterion for evaluating various conceptual models. However, unfortunately, relatively few researches have been made on interoperability between the Entity-Relationship (ER) model, which is the most dominant conceptual data model, and ontology based model. In this paper, we investigate the interoperability between ontology and the ER model. In detail we (i) reclassify components of ER model with respect to ontology concepts, (ii) identify some components that cannot be directly represented in ontology notation, and (iii) present alternative representations to the components to acquire ontologically clear ER diagrams. Additionally, we (iv) present a set of mapping rules for converting the ontologically clear ER diagram into the corresponding ontology. In a case study, we show the process of converting an ER diagram for a concise Project Management System (PMS) into the ontologically clear ER diagram and the corresponding ontology. We also describe an experiment that we undertook to test whether users understand the Ontologically-Clear ER diagram better.

• 대한물리치료과학회지
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• 제7권2호
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• pp.545-558
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• 2000

The present study was designed to investigate the effect of low power GaAsAl laser on Fos expression in the spinal cord induced by noxious mechanical stimulation. Noxious mechanical stimulation was applied to the right hind paw following 30min of low power laser treatment using different intensity and treatment point and the resulting Fos expression in the spinal cord dorsal horn was compared to that obtained in rats exposed only to the noxious mechanical stimulation. The results were summarized as follows: 1. In intact control rats, only a few Fos like immunoreactive(Fos-IR) neurons were evident in the lumbar spinal cord dorsal horn. Similarly, following prolonged inhalation anesthesia, Fos-IR neurons were absent in the dorsal horn of the lumbar spinal cord. In animals treated with noxious mechanical stimulation, neurons with nuclei exhibiting Fos immunostaining were distributied mainly in the medial half of ipsilateral laminae I-V at lumbar segments L3-5. These findings directly indicated that prolonged anesthesia used in this study did not affect the Fos expression in the spinal cord dorsal horn of intact animals and noxious mechanical stimulation treated animals. 2. In acupoint treated animals, 10mW of laser stimulation, not 3mW intensity, significantly reduced the number of Fos immunoreactive neurons in the spinal dorsal horn induced by noxious mechanical stimulation(P<.01). However, the supressive effect of low power laser stimulatin was not observed in 3m Wand 10m W of laser stimulation into non-acupoint. These data indicate that 10mW of low power laser stimulation into acupoint is capable of inhibiting the expression of Fos in the dorsal horn induced by noxious mechanical stimulation. In conclusion, these findings raise the possibility that low power laser stimulation into acupoint may be a promising alternative medicine therapy for the mechanical stimulation induced pain in the clinical field.

• 한국환경과학회지
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• 제7권3호
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• pp.375-382
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• 1998

우리나라 서해안에 위치한 서천지방 연안에 10m기상 관측탑을 설치하여 1년동안 관측한 바람자료를 사용하여 지상풍의 기초 통계량, 정상도 및 월별 정규성 검정을 조사하였다. 해륙풍과 같은 국지순환의 영향으로 8훨과 9월에 조차 북풍계열이 나타났다. 두 바람성분간의 상관계수는 6월과 9월사이, 10월과 4월사이 기간동안에 각각 양((+)과 음(-)의 값으로 나타났다. 바람의 정상도는 겨울철에 높게.여름철에 낮게 나타났다. 샘플링 시간이 증가함에 따라 S값의 modal이 감소하고 최대 발생빈도값이 5값의 낮은 영역으로의 이동이 뚜렷하게 나타났다. 패도와 초가 첨도에 기초한 월별 정규성 검정으걸 부터 바람의 동서성분은 봄철에. 남북성분은 늦여름과 초가을에 각각 정규분포를 가짐을 알 수 있었다.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2012년도 추계총회 및 학술대회 논문집
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• pp.4-4
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• 2012

Proteins enable biology to be viable through molecular interactions (such as in antigen-antibody, ligand-receptor, and drug-target) with

• 유통과학연구
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• 제17권3호
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• pp.69-83
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• 2019

Purpose - This paper investigates the long term impact of RFID investment on firm value in Korea. We wand to find out why the long term performance of some firm's RFID investment is better than others. To understand the dynamics of the long term returns from RFID investment announcements, we divide our events into groups for each of the independent firm characteristic variable such as investment time period, kind of markets, industries, solvency and growth potential. We composed portfolios based on the RFID investment announcement date for each group and evaluate the monthly abnormal excess returns. Research design, data, and methodology - Based on these calendar-time portfolios, we measure the long term returns from 86 RFID investment announcements of 46 firms from 2003 to 2017. We construct the calendar-time portfolio for 3, 6, 9, 12 months of holding periods. Using the weighted least squares method, we regress the raw monthly returns of the portfolios on the Fama-French model and Carhart(1997) model. As a result, we can get the estimated risk adjusted mean monthly abnormal excess return α_P for each of the calendar-time portfolio. Results - We found that early adopters, large firms, non-manufacturing firms have very significant excess returns. We also found modestly significant excess returns for financially stable firms and slow growing firms. Put together, top managers of the firms which plan to invest RFID should understand the strategic role of RFID adoption and the generalized business process of distribution information technology investment in Korea. Moreover, the findings of this paper provide useful trading strategies to the managers of large funds who are considering on investing in RFID adopting firms. Conclusions - Put together, the results of this paper give us a new insight into how the RFID and IT technology in general and other characteristic factors' interactions affect the long term performance of firms. Using the unbiased estimates of long term returns of the calendar-time portfolios, this paper extends the understandings on short term impact of RFID adoption of existing studies. This paper also extends the current understandings of firm characteristics that affect the long term performance of RFID adopting firms.