• 한국멀티미디어학회논문지
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• 제4권6호
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• pp.518-523
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• 2001

미세한 차이를 고감도 식별하는 카오스 이론의 프랙탈 차원과 에농 시스템에서 발생하는 이상한 끌개(Strange Attractor)를 이용하여 문자 특징을 추출, 문자 인식에 적용하는 새로운 방법을 제안함으로써 일반문자 뿐만 아니라, 문자들의 유사성에 의해 오인식되는 혼동 문자를 프랙탈 차원 해석에 의해 해소하는 고정도 문자 인식 시스템을 구현한다. 먼저, 문자 영상으로부터 문자의 고유 성질을 나타내는 망 특징 및 투영 특징, 교차거리 특징 등을 1차 구한 후, 이들 특징을 시계열 데이터로 변환한 다음, 이를 본 논문에서 제안한 수정된 에농 시스템을 이용하여, KS C 5601 표준 한글 2,350자에 대 한 각각의 문자 어트랙터를 재구성한다. 다음 단계에서는 개별 문자 어트랙터의 혼돈도를 분석하기 위해 각각의 문자에 대하여, 프랙탈 차원을 나타내는 정보 차원값(Box-counting Dimension, Natural Measure, Information Bit, Information Dimension)을 계산하여 문자 영상의 최종 특징을 구한다. 실험결과 한글 2,350자에 대하여 99.49%은 분류율을 나타내어 제안된 방법의 유효성을 보였다.

• Imaging Science in Dentistry
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• 제53권2호
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• pp.153-159
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• 2023

Purpose: The objective of this study was to assess the fractal dimension, lacunarity, trabecular microarchitecture parameters, and cortical linear measurements in the mandibles of male and female individuals to identify differences between them. Materials and Methods: In total, 116 cone-beam computed tomography scans of healthy individuals of different ages (57 men and 59 women, aged between 20 and 60 years) were selected. The following bone parameters were measured: 1) buccal, lingual, and basal cortical bone thickness in 5 standard parasagittal sections (the midline, the left and right sides of the lower lateral incisors, and the left and right sides of the lower canines); 2) the bone volume fraction of 10 sequential axial sections from each patient by creating a volume of interest in the area between the lower canines; and 3) fractal dimension and lacunarity using grayscale images of the same region of the volume of interest in the anterior mandible. Spearman correlation coefficients and the Mann-Whitney test were used. Results: A significant and positive correlation was found between age and cortical thickness, especially in the region of the central incisors. Significant differences between sexes in terms of fractal dimension, lacunarity, and bone volume were found. Women revealed lower fractal dimension values and higher lacunarity and bone volume ratio values than men. Conclusion: Fractal dimension, lacunarity, trabecular bone volume, and cortical thickness were different between men and women of different ages.

• Journal of the Korean Wood Science and Technology
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• 제38권6호
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• pp.470-479
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• 2010

본 연구는 국산 백합나무의 육안 특성을 이용한 등급구분과 실대재 휨시험을 실시하여 이들의 강도 및 강성의 특성 구명을 통해 국산 백합나무의 구조용재로서의 이용가능성을 평가하였다. 활엽수의 육안등급구분규정이 국내에 존재하지 않아 몇몇 활엽수 제재목에 대한 규정을 포함하고 있는 NSLB (Northern Softwood Lumber Bureau) 규정에 따라 육안등급을 수행하였다. 수행 결과로부터 계산된 백합나무의 휨허용응력을 NDS (National Design Specification)에 제시된 설계치와의 비교를 통해 국산 백합나무가 충분한 강도성능을 가지고 있음을 확인 하였다. 또한 백합나무 제재목을 국내 등급규정에 따라 허용응력을 산정하여 이를 적용하는 데 있어 타당성을 평가하기 위해 국내 국립산림과학원 고시에 따라 육안등급을 수행하였다. 백합나무는 국립산림과학원 고시에 제시된 비중에 따른 수종군 중 소나무류에 포함되었다. 적합분포로 판단된 웨이블분포에 따른 휨허용응력은 1등급 10.0 MPa, 2등급 7.4 MPa, 3등급 4.1 MPa로 제시된 설계치보다 높은 값이 나타났다. 본 실험의 결과로부터 국내 규정에 준하여 국산 백합나무를 구조용재로 이용이 가능함을 확인하였다. 국산 백합나무의 휨탄성계수는 국내외 기준 설계치를 모두 충족시키지 못하였으나, 국산백합나무를 구조용재로 이용하기 위해 본 실험을 통해 얻어진 백합나무의 평균 휨탄성계수를 제안하되, 1등급과 2등급은 9,000 MPa, 3등급 이하는 8,000 MPa를 적용 하는 것이 타당한 것으로 보인다.

• KIEAE Journal
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• 제12권5호
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• pp.53-61
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• 2012

As aging society progresses, it is necessary to establish a housing standard that provides a healthy, safe, and convenient environment for the elderly. The objective of the study is to propose a housing space standard that is geared towards elderly living in the urban area. Three steps were taken to attain the objective. First, characteristics of housing preference, spatial usage and furniture preference of the elderly were attained through a survey. The survey was conducted targeting the respondents of the ages 60 to 79 living in three different administrative districts in Seoul. Second, the required floor space to perform individual specific behavior using anthropometric dimension of the elderly was investigated by literature review. Lastly, floor space of each space is suggested combining each area for individual specific behavior which reflects characteristics of housing preference and spatial usage. The results of the research as follows. A bedroom was planned, which includes the function of receiving guests by giving the area for the placement of a sofa. The space for the use of dinning table for two person was planned in the kitchen and The space for the behavior of showering on a chair was planned in a bathroom. Lastly, the space for the behavior of taking off shoes on a chair was considered in the entrance area. Consequently, $35.4m^2$ is suggested as the necessary floor space for the elderly housing considering the characteristics of the elderly in urban area. However, because of space composition and space for accessibility, the additional space should be considered to plan the elderly housing.

• 대한인간공학회지
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• 제33권2호
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• pp.125-134
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• 2014

Objective: The purpose of this study is to evaluate integral seat desk used in universities through comparison of real dimension values of the desk with KS/ISO standard and questionnaire survey. Background: School furniture that helps students sit comfortably for longer periods of time and allows for better concentration on learning is important. However, seat and desk have been generally designed based on the industry practice rather than user's anthropometry, and seats and desks used in universities of Korea have not been ergonomically evaluated. Method: Real 13 dimensions of the desk used in K University were measured using tape measure and inclinometer, and the dimension values were compared to the KS standard of desk and chair for lecture room (KS G 4210) and ergonomic design principles found in relevant references. Subjective appropriacies and preference for the desk were investigated based on questionnaire survey, in which 121 (male: 91, female: 30) college students participated. Results: Several dimensions for the desk and chair investigated except desk depth and width, leg room width, seat width have not met the KS standard, but all dimensions satisfied ergonomic design principles available in references. The questionnaire survey revealed that appropriacies for desk surface size, seat pan depth, seat pan cushion and backrest curvature were under middle point of 3.0, and that those for the other dimensions showed higher scores exceeding 3.0. Conclusion: The integral seat desk widely used in universities showed some design problems in terms of standards of KS G 2010 and KS G 4210, and ergonomic design principles. Compared to the general desk with separated desk and seat, subjective preference on the integral seat desk was low. Application: This would be used as a valuable guideline when designing or choosing new integral seat desk with high satisfaction of students.

• 한국도로학회논문집
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• 제17권1호
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• pp.99-104
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• 2015

PURPOSES : It is well known that experts determined the current standard dimensions of freeway lane markings. However, rigorous engineering rationale could be insufficient regarding whether or not the standard dimensions account for how visible the markings are to the driver. In this study, we seek to optimize the dimensions of freeway lane markings to improve their visibility to drivers. METHODS : The study was conducted as follows. First, alternative lane marking dimensions were selected which could be installed in a test construction site. Second, a video recording was made while driving on the test construction site. Third, subjects were shown the recorded video and then instructed to indicate their preference from among the various lane markings. Lastly, t-tests were applied to assess the statistical significance of differences in the preferences expressed. RESULTS : According to the t-test results, there was no significant difference in the preferences expressed regarding the lane marking widths. However, with regard to the dimensions of freeway lane marking, which represents line marking lengths, gap lengths, and widths of marking, the subjects expressed a preference for specific dimensions such as 6 m:12 m,13 cm, 8 m:12 m,10 cm and 6 m:12 m,10 cm. CONCLUSIONS : In considering the dimensions of freeway lane markings and their relation to visibility by the driver, it was found that dimensions such as 6 m:12 m,13 cm, 8 m:12 m,10 cm and 6 m:12 m,10 cm.

• Korean Journal of Acupuncture
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• 제20권3호
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• pp.49-60
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• 2003

The aim of this study was to examine the effects of electroacupuncture(EA) at the PC6 (Naegwan) on normal humans using KarhunenLoeve decomposition method. Electroencephalogram(EEG) is a multi-scaled signal consisting of several components of time series with different dominant frequency ranges and different origins. EEG KarhunenLoeve decomposition method exibit site-specific and state-related differences in specific frequency bands. In this study, KarhunenLoeve decomposition method was used as a measure(D2) of complexity. 30 channel EEG study was carried out in 10 subjects (10 males; $age=21.4{\pm}0.5$ years). Results : We found that the average values and standard deviations of D2 at FP1, FP2, FTC1, FTC2, TT1, TT2, T4, TCP1, P3, P4, T6, OZ channel (p<0.05) were higher than during the acupuncture treatment, and the average values and standard deviations of D2 at F3, F8 channels(p<0.05) were lowered than during the acupuncture treatment. However, the comparison with that before and after the treatment shows no significant differences in all channels.

• 간호행정학회지
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• 제4권1호
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• pp.107-127
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• 1998

The purpose of this study was to develop an evaluation tool for the quality of nursing care in abdominal surgery patient. The target subjects of the tool were adult patients having abdominal surgery under general anesthesia. Process-outcome framework was selected for the development of the tool in this study. The results were as follows. 1. Nine standards. 40 criteria and 88 indicators were developed. A standard was summary statement of the ideal level of excellencein a dimension of quality of nursing care. which could be evaluated by criteria. Several criteria indicated a specific standard and each criterion could be measured by observable and measurable indicators. 2. The standards were divided into two dimensions. One was process dimension which contained four standards(23 criteria), the other was outcome dimension which contatined five standards(17 criteria). 3. Average CVI was .985 at 9 standards. .947 at 40 criteria. and .987 at 88 indicators. 4. The evaluation tool for the quality of nursing care in abdminal surgery patients was a criterion-referenced tool. And data collection methods of the tool were investigation of patient's record and interview( or questionnaire) with the patients. 5. Interrater reliabilities of the tool were ; r= .7572 (agreement between two raters), and pI=.8487 (intraclass correlation between five raters who rated the 84 patients). 6. Internal consistency reliability ${\alpha}$ was .6194, which was obtained from 32 criteria. Eight criteria were missed in the analyzing process because of data omission. 7. Scores of the process and the outcome dimensions showed significant. but low correlation(r= .3759, p < .001). 8. There were significant differences in total scores between the hospitals and the departments of surgery(F = 15.233. p .0001). There was also significant interaction effect between hospitals and departments to total score(F = 8.396. p = .0001). Construct validity of the toool was verified by the known-group method. these kinds of difference were expected by the nursing experts participated in the study. From these results, more specific patient classification is suggested for the development of evaluation tool of the quallity of nursing care. And indicators to be used for objective measurement for the quality of nursing care must be developed.

• 비파괴검사학회지
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• 제19권2호
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• pp.79-84
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• 1999

영상처리 방법에 의한 핵연료봉의 제원을 측정하기 위하여 영상처리 소프트웨어를 개발하고 핵연료봉의 직경을 측정하였다. 카메라와 시험체간의 거리, 카메라 위치, 조명세기 및 조명종류와 같은 요소가 핵연료봉 제원 측정에 영향을 미침을 확인하였다. 영상처리 방법에 의한 핵연료봉 직경의 백분율 측정 상대오차는 4.88%이고 백분율 측정 표준편차는 ${\pm}3.34%$였다. 한편 영상처리 방법이 아닌 기존 방법에 의한 백분율 측정 상대오차는 12.77%이고 백분율 측정 표준편차는 ${\pm}9.72%$였으며, 영상처리 방법에 의한 직경 측정 정확도가기존 방법에 의한 결과보다 약 3배정도 향상되었다.

• 한국정보통신학회논문지
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• 제18권1호
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• pp.123-128
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• 2014

본 연구에서는 이중게이트 MOSFET의 채널크기 변화에 따른 문턱전압이하 전류의 변화를 분석하였다. 이를 위하여 단채널 효과를 감소시킬 수 있는 나노소자인 이중게이트 MOSFET에 대한 정확한 해석학적 분석이 요구되고 있다. 채널 내 전위분포를 구하기 위하여 포아송방정식을 이용하였으며 이때 전하분포함수에 대하여 가우시안 함수를 사용하였다. 가우시안 함수의 변수인 이온주입범위 및 분포편차 그리고 채널크기 등에 대하여 문턱전압이하 전류 특성의 변화를 관찰하였다. 본 연구의 모델에 대한 타당성은 이미 기존에 발표된 논문에서 입증하였으며 본 연구에서는 이 모델을 이용하여 문턱전압이하 전류 특성을 분석하였다. 분석결과, 문턱전압이하 전류는 채널크기 및 가우시안 분포함수의 변수 등에 크게 영향을 받는 것을 관찰할 수 있었다.