• Asia pacific journal of information systems
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• 제23권3호
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• pp.25-53
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• 2013

This study analyzes the effect of Computer Aided Innovation (CAI) to improve R&D Capabilities empirically. Survey was distributed by e-mail and Google Docs, targeting CTO of 235 SMEs. 142 surveys were returned back (rate of return 60.4%) from companies. Survey results from 119 companies (83.8%) which are effective samples except no-response, insincere response, estimated value, etc. were used for statistics analysis. Companies with less than 50billion KRW sales of entire researched companies occupy 76.5% in terms of sample traits. Companies with less than 300 employees occupy 83.2%. In terms of the type of company business Partners (called 'partners with big companies' hereunder) who work with big companies for business occupy 68.1%. SMEs based on their own business (called 'independent small companies') appear to occupy 31.9%. The present status of holding IT system according to traits of company business was classified into partners with big companies versus independent SMEs. The present status of ERP is 18.5% to 34.5%. QMS is 11.8% to 9.2%. And PLM (Product Life-cycle Management) is 6.7% to 2.5%. The holding of 3D CAD is 47.1% to 21%. IT system-holding and its application of independent SMEs seemed very vulnerable, compared with partner companies of big companies. This study is comprised of IT infra and IT Utilization as CAI capacity factors which are independent variables. factors of R&D capabilities which are independent variables are organization capability, process capability, HR capability, technology-accumulating capability, and internal/external collaboration capability. The highest average value of variables was 4.24 in organization capability 2. The lowest average value was 3.01 in IT infra which makes users access to data and information in other areas and use them with ease when required during new product development. It seems that the inferior environment of IT infra of general SMEs is reflected in CAI itself. In order to review the validity used to measure variables, Factors have been analyzed. 7 factors which have over 1.0 pure value of their dependent and independent variables were extracted. These factors appear to explain 71.167% in total of total variances. From the result of factor analysis about measurable variables in this study, reliability of each item was checked by Cronbach's Alpha coefficient. All measurable factors at least over 0.611 seemed to acquire reliability. Next, correlation has been done to explain certain phenomenon by correlation analysis between variables. As R&D capabilities factors which are arranged as dependent variables, organization capability, process capability, HR capability, technology-accumulating capability, and internal/external collaboration capability turned out that they acquire significant correlation at 99% reliability level in all variables of IT infra and IT Utilization which are independent variables. In addition, correlation coefficient between each factor is less than 0.8, which proves that the validity of this study judgement has been acquired. The pair with the highest coefficient had 0.628 for IT utilization and technology-accumulating capability. Regression model which can estimate independent variables was used in this study under the hypothesis that there is linear relation between independent variables and dependent variables so as to identify CAI capability's impact factors on R&D. The total explanations of IT infra among CAI capability for independent variables such as organization capability, process capability, human resources capability, technology-accumulating capability, and collaboration capability are 10.3%, 7%, 11.9%, 30.9%, and 10.5% respectively. IT Utilization exposes comprehensively low explanatory capability with 12.4%, 5.9%, 11.1%, 38.9%, and 13.4% for organization capability, process capability, human resources capability, technology-accumulating capability, and collaboration capability respectively. However, both factors of independent variables expose very high explanatory capability relatively for technology-accumulating capability among independent variable. Regression formula which is comprised of independent variables and dependent variables are all significant (P<0.005). The suitability of regression model seems high. When the results of test for dependent variables and independent variables are estimated, the hypothesis of 10 different factors appeared all significant in regression analysis model coefficient (P<0.01) which is estimated to affect in the hypothesis. As a result of liner regression analysis between two independent variables drawn by influence factor analysis for R&D capability and R&D capability. IT infra and IT Utilization which are CAI capability factors has positive correlation to organization capability, process capability, human resources capability, technology-accumulating capability, and collaboration capability with inside and outside which are dependent variables, R&D capability factors. It was identified as a significant factor which affects R&D capability. However, considering adjustable variables, a big gap is found, compared to entire company. First of all, in case of partner companies with big companies, in IT infra as CAI capability, organization capability, process capability, human resources capability, and technology capability out of R&D capacities seems to have positive correlation. However, collaboration capability appeared insignificance. IT utilization which is a CAI capability factor seemed to have positive relation to organization capability, process capability, human resources capability, and internal/external collaboration capability just as those of entire companies. Next, by analyzing independent types of SMEs as an adjustable variable, very different results were found from those of entire companies or partner companies with big companies. First of all, all factors in IT infra except technology-accumulating capability were rejected. IT utilization was rejected except technology-accumulating capability and collaboration capability. Comprehending the above adjustable variables, the following results were drawn in this study. First, in case of big companies or partner companies with big companies, IT infra and IT utilization affect improving R&D Capabilities positively. It was because most of big companies encourage innovation by using IT utilization and IT infra building over certain level to their partner companies. Second, in all companies, IT infra and IT utilization as CAI capability affect improving technology-accumulating capability positively at least as R&D capability factor. The most of factor explanation is low at around 10%. However, technology-accumulating capability is rather high around 25.6% to 38.4%. It was found that CAI capability contributes to technology-accumulating capability highly. Companies shouldn't consider IT infra and IT utilization as a simple product developing tool in R&D section. However, they have to consider to use them as a management innovating strategy tool which proceeds entire-company management innovation centered in new product development. Not only the improvement of technology-accumulating capability in department of R&D. Centered in new product development, it has to be used as original management innovative strategy which proceeds entire company management innovation. It suggests that it can be a method to improve technology-accumulating capability in R&D section and Dynamic capability to acquire sustainable competitive advantage.

• 간호행정학회지
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• 제6권1호
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• pp.135-146
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• 2000

The purpose of this study was to develope, based on the Nursing Intervention Classification (NIC) system. a set of standardized nursing interventions which had been validated. and their associated activities. for use with nursing diagnoses related to home health care for women who have had a caesarian delivery and for their newborn babies. This descriptive study for instrument development had three phases: first. selection of nursing diagnoses. second, validation of the preliminary home health care interventions. and third, application of the home care interventions. In the first phases, diagnoses from 30 nursing records of clients of the home health care agency at P. medical center who were seen between April 21 and July 30. 1998. and from 5 textbooks were examined. Ten nursing diagnoses were selected through a comparison with the NANDA (North American Nursing Diagnosis Association) classification In the second phase. using the selected diagnoses. the nursing interventions were defined from the diagnoses-intervention linkage lists along with associated activities for each intervention list in NIC. To develope the preliminary interventions five-rounds of expertise tests were done. During the first four rounds. 5 experts in clinical nursing participated. and for the final content validity test of the preliminary interventions. 13 experts participated using the Fehring's Delphi technique. The expert group evaluated and defined the set of preliminary nursing interventions. In the third phases, clinical tests were held at in a home health care setting with two home health care nurses using the preliminary intervention list as a questionnaire. Thirty clients referred to the home health care agency at P. medical center between October 1998 and March 1999 were the subjects for this phase. Each of the activities were tested using dichotomous question method. The results of the study are as follows: 1. For the ten nursing diagnoses. 63 appropriate interventions were selected from 369 diagnoses interventions links in NlC., and from 1.465 associated nursing activities. From the 63 interventions. the nurses expert group developed 18 interventions and 258 activities as the preliminary intervention list through a five-round validity test 2. For the fifth content validity test using Fehring's model for determining lCV (Intervention Content Validity), a five point Likert scale was used with values converted to weights as follows: 1=0.0. 2=0.25. 3=0.50. 4=0.75. 5=1.0. Activities of less than O.50 were to be deleted. The range of ICV scores for the nursing diagnoses was 0.95-0.66. for the nursing interventions. 0.98-0.77 and for the nursing activities, 0.95-0.85. By Fehring's method. all of these were included in the preliminary intervention list. 3. Using a questionnaire format for the preliminary intervention list. clinical application tests were done. To define nursing diagnoses. home health care nurses applied each nursing diagnoses to every client. and it was found that 13 were most frequently used of 400 times diagnoses were used. Therefore. 13 nursing diagnoses were defined as validated nursing diagnoses. Ten were the same as from the nursing records and textbooks and three were new from the clinical application. The final list included 'Anxiety', 'Aspiration. risk for'. 'Infant behavior, potential for enhanced, organized'. 'Infant feeding pattern. ineffective'. 'Infection'. 'Knowledge deficit'. 'Nutrition, less than body requirements. altered', 'Pain'. 'Parenting'. 'Skin integrity. risk for. impared' and 'Risk for activity intolerance'. 'Self-esteem disturbance', 'Sleep pattern disturbance' 4. In all. there were 19 interventions. 18 preliminary nursing interventions and one more intervention added from the clinical setting. 'Body image enhancement'. For 265 associated nursing activities. clinical application tests were also done. The intervention rate of 19 interventions was from 81.6% to 100%, so all 19 interventions were in c1uded in the validated intervention set. From the 265 nursing activities. 261(98.5%) were accepted and four activities were deleted. those with an implimentation rate of less than 50%. 5. In conclusion. 13 diagnoses. 19 interventions and 261 activities were validated for the final validated nursing intervention set.

• 대한방사선치료학회지
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• 제26권2호
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• pp.337-343
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• 2014

목 적 : 최근 시행되고 있는 가임기 여성의 유방암 토모치료 시 치료영역 외에서 발생되는 산란 및 누설에 의한 난소산란선량을 측정하여 평가하고자 한다. 대상 및 방법 : 인체모형팬텀(Aldorson Rando phantom, USA)을 대상으로 전산화단층영상 2.5 mm 획득 후, Tomotherapy Planning station(Tomotherapy, Inc, USA)을 이용하여 좌측 유방암 환자의 토모테라피 치료계획(Tomotherapy Helical & Tomotherapy Direct)을 수립하였다. 난소의 산량 선량 측정을 위한 측정 지점은 치료계획면적의 30 cm 아래 떨어진 골반의 좌우 위치로 직경 1.5 mm, 길이가 12mm인 저에너지용 보상필터가 들어있는 종류의 유리선량계 (GD-352M, ASAHI TECHNO GLASS CO, Japan)를 이용하여 각 5회씩 측정하여 평균하였으며, 선형지수-선량반응모델을 이용한 장기등가선량(organ equivalent dose: OED)으로 평가하였다. 결 과 : 토모 Helical 및 토모 Direct의 두 가지 방식으로 측정된 난소의 산란선량은 좌측 난소부위가 각각 평균 $64.94{\pm}0.84mGy$, $37.64{\pm}1.20mGy$이고, 우측 난소부위가 평균 $64.38{\pm}1.85mGy$, $32.96{\pm}1.11mGy$로 나타났다. 이는 토모치료 시 비교적 모니터 단위(MU)가 크고 조사 시간이 긴 토모Helical 방식이 토모Direct에 비하여 측정된 산란선량의 양이 보다 약 1.8배 높은 경향을 보였다. 결 론 : 가임기 여성의 유방암 토모테라피 시 발생하는 좌우측 난소의 산량선량은 ICRP 권고 선량이하로, 불임 및 2차 암 발생에 대한 우려 수준은 현저히 낮지만 향후 유방암 발생 연령층이 낮아지고, 토모테라피와 같이 고정밀 영상유도장치를 이용한 방사선치료가 발달할수록, 가임기 여성 환자의 난소산란선량에 대한 임상적 추적조사가 더욱 필요할 것으로 사료된다.

• 한국병원경영학회지
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• 제9권1호
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• pp.66-94
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• 2004

The objective of this study is to examine how to maximize the efficiency of hospital management by minimizing the unit cost of hospital operation. For this purpose, this paper proposes to develop a model of the profit maximization based on the cost minimization dictum using the statistical tools of arriving at the maximum likelihood values. The preliminary survey data are collected from the annual statistics and their analyses published by Korea Health Industry Development Institute and Korean Hospital Association. The maximum likelihood value statistical analyses are conducted from the information on the cost (function) of each of 36 hospitals selected by the random stratified sampling method according to the size and location (urban or rural) of hospitals. We believe that, although the size of sample is relatively small, because of the sampling method used and the high response rate, the power of estimation of the results of the statistical analyses of the sample hospitals is acceptable. The conceptual framework of analyses is adopted from the various models of the determinants of hospital costs used by the previous studies. According to this framework, the study postulates that the unit cost of hospital operation is determined by the size, scope of service, technology (production function) as measured by capacity utilization, labor capital ratio and labor input-mix variables, and by exogeneous variables. The variables to represent the above cost determinants are selected by using the step-wise regression so that only the statistically significant variables may be utilized in analyzing how these variables impact on the hospital unit cost. The results of the analyses show that the models of hospital cost determinants adopted are well chosen. The various models analyzed have the (goodness of fit) overall determination (R2) which all turned out to be significant, regardless of the variables put in to represent the cost determinants. Specifically, the size and scope of service, no matter how it is measured, i. e., number of admissions per bed, number of ambulatory visits per bed, adjusted inpatient days and adjusted outpatients, have overall effects of reducing the hospital unit costs as measured by the cost per admission, per inpatient day, or office visit implying the existence of the economy of scale in the hospital operation. Thirdly, the technology used in operating a hospital has turned out to have its ramifications on the hospital unit cost similar to those postulated in the static theory of the firm. For example, the capacity utilization as represented by the inpatient days per employee tuned out to have statistically significant negative impacts on the unit cost of hospital operation, while payroll expenses per inpatient cost has a positive effect. The input-mix of hospital operation, as represented by the ratio of the number of doctor, nurse or medical staff per general employee, supports the known thesis that the specialized manpower costs more than the general employees. The labor/capital ratio as represented by the employees per 100 beds is shown to have a positive effect on the cost as expected. As for the exogeneous variable's impacts on the cost, when this variable is represented by the percent of urban 100 population at the location where the hospital is located, the regression analysis shows that the hospitals located in the urban area have a higher cost than those in the rural area. Finally, the case study of the sample hospitals offers a specific information to hospital administrators about how they share in terms of the cost they are incurring in comparison to other hospitals. For example, if his/her hospital is of small size and located in a city, he/she can compare the various costs of his/her hospital operation with those of other similar hospitals. Therefore, he/she may be able to find the reasons why the cost of his/her hospital operation has a higher or lower cost than other similar hospitals in what factors of the hospital cost determinants.

• 보건의료산업학회지
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• 제2권1호
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• pp.137-154
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• 2008

The increase of the supply of medical service and the increase of hospitals have intensified the competition of hospitals, and the advancement towards internationalization in the opening of medical industry has triggered the infinite competition of medical profession. In addition, the high expectation of customers and quality improvement in the medical care in accordance with the improvement of overall income, and the change of active role of medical consumers according to the popularization and the improvement of rights awareness reflect the customer needs and choice in the medical service. Customers wanted to receive the kind and pleasant service under the up-to-date medical service. Therefore, as a solution, hospital coordinators were emerged for the purpose of smooth treatment and customer satisfaction by generalizing all service of hospital. Accordingly, this thesis attempted to investigate the effect of hospital coordinator education curriculum on the education satisfaction and the quality of medical service. In order to solve the purpose of this study, I, author reviewed the existing literatures, established hypothesis, and verified hypothesis by using the variety of statistics techniques such as reliability, validity, frequency analysis, and regression analysis. The verification of hypothesis is as followings: First, among education training factors of hospital coordinators, the quality of instructor significantly affects the satisfaction of hospital coordinator education training. Second, among training factors of hospital coordinator, the attitude of trainee significantly affects the training satisfaction of hospital coordinator. Third, among education training factors of hospital coordinator, education course significantly affects the training satisfaction of hospital coordinator education. As the qualities of instructor are better equipped, the satisfaction of education becomes higher. It indicates that the education method of instructors is important as an index to represent the qualities of instructor such as the appropriateness of education method, preparation, passion, visual materials, the adequacy of education procession, and specialized knowledge, and it has important effect on the satisfaction of education. In order to enhance the satisfaction of hospital coordinator education, the creation of education environment, making trainee concentrate on the education, is required by appropriately allocating programs, arousing interest in education, based on the attitude of trainee, discussion, and preliminary programs, preparation, ahead of enforcement of education. Fourth, the satisfaction of hospital coordinator education training significantly affects the reliability among the qualities of medical service. Fifth, satisfaction of hospital coordinator education training significantly affects hospitality I kindness among the qualities of medical service. If the education satisfaction of trainee is high, it is effective in the practical application such as dealing with complaints, the duty performance for the patients, and so on in offering the medical service, related to reliability and furthermore, we can find the positive change in the attitude change of medical professions related to the reliability of hospital coordinator. In addition, in the process of offering medical services such as the kind explanation on the duty, rapid response to the customers inquiry, and tidy uniform, practical effect was verified. Sixth, the education training factor of hospital coordinator significantly affects the reliability among the quality of medical service. Seventh, the education training factors of hospital coordinator significantly affect hospitality/kindness. In the education of hospital coordinator, the methods to attract the interest of trainee by emphasizing reliability should be sought and for gaining the practical effect of hospital coordinator education, the sufficient preparation and investigation on the education curriculum should be prerequisite and under this condition, intensified discussion on the instructor and education course is needed. In the design of education course, more education hours and subjects should be allocated in the part of hospitality in order to improve the practical application of hospitality. Therefore, it is meaningful in a sense that this study newly approached the components of hospital coordinator education and the need to modify the quality components of medical service in accordance with the study subjects was raised. This study also finds its meaning in that it provides basic materials for the study of future hospital coordinator education by suggesting the system development model of hospital coordinator education through preliminary study of education training. In addition, this study is meaningful in the aspect that it suggested the direction of education training by showing how the hospital coordinator education training would applied to the hospital coordinator course of the Continuing Education Center at Pusan and Kyungnam National University to some extent. Since all investigation of this study was approached from the side of hospital coordinator, the thoughts of patients who are beneficiaries of medical service, and care givers cannot be identified. Therefore, the satisfaction of patients and care givers through the experience of medical service, which is the essential prerequisite of medical service, should be importantly considered and investigated. Accordingly, The study of comparing and analyzing the views of both patients and care givers should be carried out in the future.

• 자원환경지질
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• 제51권2호
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• pp.167-176
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• 2018

고준위방사성폐기물 처분장 부지선정을 위해서는 암종, 지질구조, 지진, 수리지질, 지구화학, 지질공학 및 지열 등과 같은 다양한 지질학적 인자들에 대한 고려가 필요하며, 특히 선형구조는 다양한 지질인자의 특성을 반영하기 때문에 원자력 발전소, 고준위방사성폐기물 처분장 등과 같은 국가 중요시설물의 후보부지 선정에 있어 매우 중요한 기초자료로 활용될 수 있다. 본 논문에서는 선형구조분석을 통해 고준위방사성폐기물 광역 처분부지 선정을 실시한 핀란드의 선형구조 분류 방법을 국내 선형구조 자료에 적용하여 살펴보았다. 이를 위하여 기존에 한국지질자원연구원에서 보유한 선형구조도와 신규로 구조지질학, 고지진학, 지형학 전문가들로부터 획득한 새로운 선형구조 자료를 분석에 이용하였다. 새로운 선형구조 분석 자료의 신뢰성 확보를 위해 한반도 지역을 최근에 촬영한 위성영상과 국토지리정보원에서 제공하는 수치표고모델로 제작한 고해상도의 음영기복도를 이용하였다. 취득한 자료들의 전체적인 방향성 분석 결과에서는 북북동-남남서 방향이 가장 우세하게 관찰되었지만, 분석자들의 판독기준의 차이에 따라서 동북동-서남서 및 북북서-남남동 방향의 선형구조들도 높게 판독 되었다. 핀란드의 분류 방법을 적용하여, 광역후보부지 선정에 사용되는 등급 1과 등급 2에 해당되는 선형구조들의 기하학적인 발달특성을 상호 비교해 보았다. 그 결과에서는 전체적으로 등급 1의 경우에는 공통적으로 북북동-남남서 방향이 가장 우세하였으며, 서북서-동남동 방향의 선형구조도 빈도가 높게 나타났다. 등급 2의 경우에도 북북동-남남서 방향의 선형구조가 가장 우세하게 발달하고 있으며, 분석자에 따라 서북서-동남동 또는 동북동-서남서 방향의 선형구조도 빈도가 높게 나타났다. 같은 자료를 바탕으로 실시한 선형구조분석에서도 상이한 판독 결과를 보이는 것은 판독자의 주관적인 경험 및 기준이 작용하였기 때문으로 여겨진다. 따라서 신뢰도 높은 한반도 광역선형구조도를 발간하기 위해서는 상이한 자료들을 통합하는 과정에서 명확한 통합 기준의 설정이 필요하며, 지구물리탐사자료와 같은 추가적인 데이터를 통한 분석이 요구된다.

• 방사성폐기물학회지
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• 제8권4호
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• pp.311-318
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• 2010

공학적 안전설비 공기정화계통의 규제지침인 Reg. Guide 1.52(Rev.3)의 변경사항중 성능시험과 관련한 운전가능성 시험시간 단축, HEPA 필터 현장누설시험용 시험물질 변경 및 활성탄 성능시험 Methyl Iodidie 투과허용율 상향 변경을 영광 5,6호기에 적용하고자, 모사실험장치와 현장 설비를 활용하여 기술적 타당성을 확인하는 실험을 수행하였다. 10시간 이상의 장시간 운전가능성 시험을 통해 계통내 습분을 제거하여도 시험후 1~4일만에 회복됨을 확인하여 운전가능성 시험은 기기적 운전가능성 점검에 적합한 매월 15분 이상의 시험을 수행하는 것이 타당함을 확인하였다. HEPA 필터 현장누설시험용 시험물질 변경을 위해 DOP와 PAO의 에어로졸 입자크기, 발생량, 누설인지도를 비교한 결과 PAO는 원전에서도 DOP 대체시험물질로 사용 가능함을 확인하였다. 베드깊이 4 인치 이상의 활성탄여과기에 대한 Methyl Iodide의 투과율 허용치가 0.175 %에서 0.5 %로 상향 변경된 것은, ASTM D3803(1989)으로의 활성탄 성능시험 방법 변경에 따른 것으로서, $30^{\circ}C$ 상대습도 95 %에서의 Methyl Iodide 투과허용율 0.5 %가 사용 중 활성탄의 성능을 시험하기에 충분히 보수적인 시험방법임을 확인하였다. 본 실험 결과를 바탕으로 영광 5,6호기는 인허가변경을 완료하였다.

• 한국지반공학회논문집
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• 제28권5호
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• pp.13-25
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• 2012

그라운드 앵커공법은 현재 우리나라에서 가장 일반적으로 사용되는 사면보강공법들 중 하나이다. 앵커로 보강된 사면의 안정성을 장기간 확인하기 위해서는 그라운드 앵커의 긴장력을 측정하는 것이 매우 중요하다. 그러나 현재 현장에서 주로 사용되는 스트레인게이지 및 V/W타입의 로드 셀은 전자기파에 의한 노이즈 발생이 크고 습기 또는 수분의 영향으로 인해 측정값에 오차가 발생할 수 있으며 자기열화 등으로 장기간의 모니터링에 한계가 있다. 또한 앵커의 개별 텐던에 발생하는 미세한 변화를 정확히 감지할 수 없는 단점이 있어 이를 개선할 수 있는 방안으로 광섬유 센서를 이용하여 강연선의 변형률을 측정할 수 있는 광섬유 센서 내장형 텐던이 개발되었다. 이 광섬유 센서 내장형 텐던은 단기간의 앵커 장력 측정에 성공적으로 적용된 사례가 보고되었으나 장기간에 걸친 장력 변화를 측정하기 위해서는 온도에 의한 광섬유 센서의 변형률을 보상하여야 한다. 이 논문에서는 광섬유 센서 내장형 텐던을 이용하여 그라운드 앵커의 장력모니터링 시 지중온도 변화에 의한 영향을 보상하는 실용적인 방안에 대하여 기술하였다. 먼저 실내실험을 통하여 광섬유 센서 내장형 텐던의 온도반응계수(${\beta}^{\prime}$)를 $2.0{\times}10^{-5}/^{\circ}C$로 결정하고 실제 현장에 설치된 광섬유 센서를 이용하여 깊이별 지중온도 변화값을 측정하였다. 연구 대상지역(여수)의 기상청 지중온도 측정 결과 자료와의 비교를 통하여 결정된 온도반응계수(${\beta}^{\prime}$)를 이용한 광섬유 센서 내장형 텐던의 온도반응 성능을 검증하였다. 최종적으로 광섬유 센서 내장형 텐던을 이용하여 실제 사면에 설치된 인장형 앵커와 압축형 앵커의 계절별 긴장력을 모니터링하고 기상청 지중온도 측정자료와 온도반응계수를 이용하여 온도보상을 실시하여 기존 V/W타입의 로드 셀 측정 결과와 비교하였다. 제안된 광섬유 센서 내장형 텐던의 온도반응계수와 기상청 지중온도 측정결과를 이용한 앵커의 온도보상 방법에 의해 측정된 긴장력 모니터링 결과가 계절에 따른 지중온도 변화에 상관없이 로드 셀 결과와 일관성 있게 비교되어 제안된 온도보상 방법이 매우 실용적이며 합리적인 것으로 나타났다.

• 대한핵의학회지
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• 제32권3호
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• pp.225-237
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• 1998

목적: $H_2^{15}O$ 양전자단층촬영으로 작업기억을 조사할 때 뇌기능을 국소화한 뇌기능지도를 만들기 위해 동원되는 통계적 가정과 추론의 여러 방법을 해석하고 뇌활성화와 관련된 뇌기능 국소화 방법에 영향을 미치는 요소를 조사하였다. 대상 및 방법: 정상인 6명에 대하여 각각 대조과제, 언어성 작업기억 활성화과제 2종류, 시각적 작업기억 활성화과제 1종류를 수행시키며 뇌혈류 $H_2^{15}O$ PET 촬영을 시행하였다. SPM96 소프트웨어를 이용하여 각 영상과 표준지도의 뇌피질 경계가 일치 되도록 부분 선형적으로 변형하였으며 선형화한 비선형적 변형 방법으로 사람에 따라 나타나는 뇌피질 및 내부 구조의 미세한 차이를 제거하였다. 공간정규회된 영상들을 16mm의 FWHM을 갖는 가우시안 커널로 중첩적분하여 편평화하였다. 각 화소의 방사능 계수는 뇌피질전체 뇌혈류, 활성화에 의한 특정 효과, 여러 교란변수의 영향과 오차의 선형 결합으로 이루어진다는 일반선형모델을 가정하고 공분산분석 방법으로 전체 뇌혈류 차이를 제거하였다. 각 화소의 방사능 계수가 자극과 뇌활성화 작업에 상관없을 경우 평탄한 무작위 가우스장의 행동을 따른다고 가정하고 특정화소의 계수차이가 이 무작위장의 정상적인 교란 이상인지 검정하였다. 화소별 t 값을 Z 값으로 바꾸어 표현하고 가설검정 결과에 따라 화소, 덩어리, 화소 또는 덩어리의 차이가 얼마나 유의한지 제시하였다. 결합분석을 하여 여러 과제를 수행할 때 동시에 화소의 계수가 증가하는 곳을 찾았다. 각 화소의 Z 값을 3차원으로 렌더링한 표준지도와 투명유리뇌에 투사하여 활성화된 부위를 알아볼 수 있게 하였다. 결과: 피검자 모두 성공적으로 검사를 마쳤으며 대조 과제와 기억 과제를 수행하는 동안 피험자는 평균 95%를 맞췄다. 활성화된 덩어리의 개수는 언어성 기억과제 I에서 4개, 언어성 기억과제 II에서 9개, 시각적 기억과제에서 9개, 결합분석에서 6개였다. 언어성 기억과제에서는 주로 왼쪽 뇌가, 시각적 기억과제에서는 오른쪽 뇌가 활성화되었다. 결론: $H_2^{15}O$ 양전자 단층촬영술과 통계적 파라메터 지도작성법이 언어성 및 시각적 작업기억과 관련되어 활성화된 지 영역을 찾는데 유용하였다.

• Toxicological Research
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• 제33권2호
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• pp.107-118
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• 2017

Although alternative test methods based on the 3Rs (Replacement, Reduction, Refinement) are being developed to replace animal testing in reproductive and developmental toxicology, they are still in an early stage. Consequently, we aimed to develop alternative test methods in male animals using mouse spermatogonial stem cells (mSSCs). Here, we modified the OECD TG 489 and optimized the in vitro comet assay in our previous study. This study aimed to verify the validity of in vitro tests involving mSSCs by comparing their results with those of in vivo tests using C57BL/6 mice by gavage. We selected hydroxyurea (HU), which is known to chemically induce male reproductive toxicity. The 50% inhibitory concentration ($IC_{50}$) value of HU was 0.9 mM, as determined by the MTT assay. In the in vitro comet assay, % tail DNA and Olive tail moment (OTM) after HU administration increased significantly, compared to the control. Annexin V, PI staining and TUNEL assays showed that HU caused apoptosis in mSSCs. In order to compare in vitro tests with in vivo tests, the same substances were administered to male C57BL/6 mice. Reproductive toxicity was observed at 25, 50, 100, and 200 mg/kg/day as measured by clinical measures of reduction in sperm motility and testicular weight. The comet assay, DCFH-DA assay, H&E staining, and TUNEL assay were also performed. The results of the test with C57BL/6 mice were similar to those with mSSCs for HU treatment. Finally, linear regression analysis showed a strong positive correlation between results of in vitro tests and those of in vivo. In conclusion, the present study is the first to demonstrate the effect of HU-induced DNA damage, ROS formation, and apoptosis in mSSCs. Further, the results of the current study suggest that mSSCs could be a useful model to predict male reproductive toxicity.