• Journal of Biosystems Engineering
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• 제43권3호
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• pp.237-246
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• 2018

Purpose: This study (a) investigated the effect of microwave power intensity and sample thickness on microwave drying characteristics of radish strips, and (b) determined the best-fit drying model for describing experimental drying data, effective moisture diffusivity ($D_{eff}$), and activation energy ($E_a$) for all drying conditions. Methods: A domestic microwave oven was modified for microwave drying and equipped with a small fan installed on the left upper side for removing water vapor during the drying process. Radishes were cut into two fixed-size strip shapes (6 and 9 mm in thickness). For drying experiments, the applied microwave power intensities ranged from 180 to 630 W at intervals of 90 W. Six drying models were evaluated to delineate the experimental drying curves of both radish strip samples. The effective moisture diffusivity ($D_{eff}$) was determined from Fick's diffusion method, and the Arrhenius equation was applied to calculate the activation energy ($E_a$). Results: The drying time was profoundly decreased as the microwave power intensity was increased regardless of the thickness of the radish strips; however, the drying rate of thicker strips was faster than that of the thinner strips up to a certain moisture content of the strip samples. The majority of the applied drying models were suitable to describe the drying characteristics of the radish strips for all drying conditions. Among the drying models, based on the model indices, the best model was the Page model. The range of estimated $D_{eff}$ for both strip samples was from $2.907{\times}10^{-9}$ to $1.215{\times}10^{-8}m^2/s$. $E_a$ for the 6- and 9-mm strips was 3.537 and 3.179 W/g, respectively. Conclusions: The microwave drying characteristics varied depending on the microwave power intensity and the thickness of the strips. In order to produce high-quality dried radish strips, the microwave power intensity should be lower than 180 W.

• 보건행정학회지
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• 제10권1호
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• pp.111-125
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• 2000

To compare the differences in the recognition on hospital utilization and satisfaction, 368 hospital employees and 485 patients were selected in four hospitals in Seoul and Kyung-gi do. The survey was done using a constructed form of checklist from Apr. 30 to May 10, 1999. And the results are as follows: l. Gaining knowledge of hospitals available among hospital employees differed from that of patients. When finding out about sources of information concerning hospitals, direct visit to the hospital was recognized to be the main factor for the hospital employees in contrast to the patients' recognition which were mass media, personal involvement of job related workplace and recommendations from other hospitals. There was no difference between university and general hospitals. 2. The factors that concern which hospital to choose there was a difference between hospital employees and patients. Hospital employees recommended their own hospital solely based on the reason that it was their work place. On the other hand, the patients made a choice based on the type of medical staff, transportation available and whether it was a university hospital or not. There was no difference between university and general hospitals. 3. The recognition of employees concerning hospital image of a hospital between hospital employees and patients was different. In university hospitals, the employees recognized the name value of university hospital and cooperation as most important, whereas the patients thought convenience, kindness were the main factors. Patients considered general hospitals to be more convenient. There was some difference between university and general hospitals. For university hospitals employees' recognition was higher and for the general hospital patients' recognition is higher on hospital image. 4. The recognition of employees was different from that of patients' on hospital satisfaction. The patients' satisfaction was higher than that of employees'. There was no difference between university and general hospitals. Based on the above findings, the employees' recognition on hospital utilization and satisfaction was different from that of the patients, but there was no difference between university and general hospitals. In both groups choice of hospital was associated with satisfaction. Results showing difference between employees' and patients' recognition can be applied to implement customer-oriented attitude and be used as a baseline data for internal-external marketing planning of hospital management. The study may be limited in that the results cannot be generalized due to its small sample size and not being able to reflect demographic variables and life style. Further studies to investigate the difference of hospital utilization and hospital satisfaction will be necessary to define demographic characteristics and recognition of employees which influences patients' hospital satisfaction.

• Journal of Welding and Joining
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• 제34권2호
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• pp.1-10
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• 2016

The use of materials for modern lightweight auto-bodies is becoming more complex than hitherto assemblies. The high strength materials nowadays frequently used for more specific fields such as the front and rear sub frames, seat belts and seats are mounted to the assembled body structure using bolt joints. It is desirable to use nuts attached to the assembled sheets by projection welding to decrease the number of loose parts which improves the quality. In this study, nut projection welding was carried out between a nut of both boron steel and carbon steel and ultra-high strength hot-stamped steel sheets. Then, the joints were characterized by optical and scanning electron microscope. The mechanical properties of the joints were evaluated by microhardness measurements and pullout tests. An indigenously designed sample fixture set-up was used for the pull-out tests to induce a tensile load in the weld. The fractography analysis revealed the dominant interfacial fracture between boron steel nut weld which is related to the shrinkage cavity and small size fusion zone. A non-interfacial fracture was observed in carbon steel nut weld, the lower hardness of HAZ caused the initiation of failure and allowed the pull-out failure which have higher in tensile strengths and superior weldability. Hence, the fracture load and failure mode characteristics can be considered as an indication of the weldability of materials in nut projection welding.

• 한국재료학회지
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• 제3권5호
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• pp.553-561
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• 1993

본 연구에서는 입계의 성질을 이용한 PTCR 재료에 입계 modifier로서 $Bi_2O_3$를 첨가하고 입계의 미세구조와 결함농도를 변화시켜 이에 따른 소결 및 전기적 특성변화를 TMA, XRD, 복합 임피던스방법 등을 이용하여 해석하였다. 실험 결과 Y이 도우핑된 $BaTiO_3$PTCR 재료에 $Bi_2O_3$를 첨가하였을때 약 0.1mol%까지 고용이 되는 것으로 밝혀졌다. $Bi_2O_3$를 고용한계 이하로 첨가시에는 생성되는 vacancy등의 결함으로 말미암아 $Y-BaTiO_3$의 치밀화가 촉진되었으나, 그 이상 첨가하면 치밀화 뿐만 아니라 결정립 성장도 억제되었다. $Bi_2O_3$의 첨가량에 따라 계내에 존재하는 각 이온의 반경, 결함 반응식 및 격자 탄성 변형 에너지 등을 고려하면 $Y-BaTiO_3$결정립 내부에 Ba와 Ti vacancy가 동시에 생길 수 있어 고온저항이 높아짐을 알 수 있었다. BN은 $BaTiO_3$에 고용이 되지 않는 것으로 밝혀졌으며 $B_2O_3$를 주성분으로한 액상형성으로 인하여 저온에서의 급격한 치밀화가 관찰되었다. 또 Ba-Y-Ti-B-O의 비정질 상이 tripie junction에 존재함으로써 상온저항이 크게 변화하였으며, PTCR jump도 높아졌다.

• Clinical and Experimental Pediatrics
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• 제54권3호
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• pp.117-122
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• 2011

Purpose: Natural history and consequences of the novel 2009 influenza A H1N1(2009 H1N1) infection in immunocompromised pediatric patients are not yet fully understood. In this study, we investigated the clinical features and outcomes of the 2009 H1N1 infection in pediatric patients with hematological and oncological diseases. Methods: We retrospectively reviewed the medical records of 528 patients who had hematological and oncological diseases and who were treated at 7 referral centers located in the Yeungnam region. Among the 528 patients, 27 with definite diagnosis of 2009 H1N1 infection were the subjects of this study. All patients were divided into the following 3 groups: patients who were receiving chemotherapy (group 1), patients who were immunosuppressed due to a nonmalignant hematological disease (group 2), and patients who were off chemotherapy and had undergone their last chemotherapy course within 2 years from the influenza A pandemic (group 3). Results: All 28 episodes of 2009 H1N1 infection were treated with the antiviral agent oseltamivir ($Tamiflu^{(R)}$), and 20 episodes were treated after hospitalization. Group 1 patients had higher frequencies of lower respiratory tract infection and longer durations of fever and hospitalization as compared to those in group 2. Ultimately, all episodes resolved completely with no complications. Conclusion: These results suggest that early antiviral therapy did not influence the morbidity or mortality of pediatric patients with hematological and oncological diseases in the Yeungnam region of Korea after the 2009 H1N1 infection. However, no definite conclusions can be drawn because of the small sample size.

• Restorative Dentistry and Endodontics
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• 제24권4호
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• pp.578-584
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• 1999

The purpose of this experiment was to determine: (1) the safe automatic apical reverse setting that prevents overinstrumentation of the root canal, using Tri Auto ZX$^{(R)}$ and (2) the effect of various irrigant on such instrumentation. The instrumentation was carried out with the automatic apical reverse setting of 0.5, 1.0, 1.5, and 2.0. The root canal irrigants used in usual manner were normal saline(0.9%), NaOCl(2.5%), and RC Prep$^{(R)}$. For each reverse setting and each irrigant, ten teeth were used with the total of 120 teeth. The distance between the file tip and the apical constriction was determined by stereomicroscope using the point that the file began to rotate in reverse direction. When the reverse setting mode was set to 0.5, 18 of 30 were overinstrumented. If these were discriminated by irrigant, 10 of 6 with 0.9% saline, 10 of 6 with NaOCl, and 10 of 6 with RC Prep$^{(R)}$ has the file tip located 0.57${\pm}$0.30mm, 0.73${\pm}$0.39mm, and 0.26${\pm}$0.25mm beyond the apical constriction respectively. In 1.0 setting 15 of 29 were over the apical constriction, and the distribution was 6 in saline, 5 in NaOCl, and 4 in RC Prep$^{(R)}$. The mean distance over the apical constriction was 0.28${\pm}$0.13mm with saline, 0.75${\pm}$0.61mm with NaOCl, and 0.25${\pm}$0.17mm with RC Prep$^{(R)}$. When the autoatic reverse mode was set to 1.5, and 2.0, 5, and 1 teeth were found to be overinstrumented in respective settings. But there were large variations in overinstrumented distances when an attempt was made to compare the effect of irrigants on this overinstrumentations and they were meaningless for the small sample size. When all of the autoreverse setting were combined to compare the number of overinstrumented teeth with each irrigant, there were no significant differences (14 for normal saline, 12 for NaOCl, 13 for RC Prep$^{(R)}$). When 0.5 or 1.0 automatic apical reverse setting mode was used the Tri Auto ZX$^{(R)}$ in clinical application, the possibility of overinstrumentation beyond the apical constriction exists in 55.9% of cases. Therefore 1.5 or 2.0 setting is safer for the preparation inside the canal but this type setting needs additional apical hand preparation of the root canal because the accuracy is lower than 0.5 or 1.0 setting.

• 중소기업융합학회논문지
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• 제1권1호
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• pp.1-8
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• 2011

정보화경영이 성공하려면 정보화혁신에 대한 적극적인 마인드가 형성되어야 하고, 정보화경영체제가 지향하는 바에 대한 변화와 관리가 효과적으로 이루어져야 한다. 그리고 그러한 노력은 지속적으로 이루어질 필요도 있는데, 이를 위해서는 그에 적합한 문화적 특성이 필요할 것이다. 이러한 이유로 정보화경영지향성과 기업문화의 적합도는 중요하다 할 수 있고, 그 적합도가 높을 때 정보화경영활동의 성공확률은 높다고 할 수 있다. 이러한 이유로 이 연구에서는 정보화경영지향성, 기업문화, 정보화경영지향성과 기업문화의 적합도가 전반적인 정보화경영활동의 이행수준에 미치는 영향을 규명하고자 하였다. 또한 정보화경영지향성과 경영성과간의 관계에 정보화경영활동의 이행수준이 매개효과를 가지는지도 검정하고자 하였다. 이 연구의 결과를 요약하면 다음과 같다. 첫째, 기업이 적극적으로 정보화경영을 지향하면, 정보화경영활동의 이행수준, 경영성과 등이 개선되는지를 검정하였다. 둘째, 기업문화가 정보화경영활동의 이행수준에 미치는 영향을 검정하였다. 셋째, 정보화경영지향성과 기업문화의 적합도가 정보화경영활동의 이행수준에 미치는 영향을 검정하였다. 넷째, 정보화경영지향성과 경영성과간의 관계에서 정보화경영활동이 이행수준의 매개효과를 가지는지를 검정하였다.

• 한국비블리아학회지
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• 제25권4호
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• pp.291-312
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• 2014

본 연구는 우리나라 성인들의 공공도서관 이용을 예측할 수 있는 요인을 규명하기 위한 목적으로, 공공도서관 방문빈도가 그 개인의 인구사회학적 특성, 그가 이용하는 개별 공공도서관의 서비스 자원 투입 및 산출 특성, 그리고 거주지의 기초 및 광역 지방자치단체의 공공도서관 투자 수준과 어떤 관계를 갖고 있는지 살펴보았다. 자료수집을 위하여 우리나라 인구의 성별, 연령, 지역적 분포 등을 고려한 유층표집을 적용하여 대한민국 전역에 거주하는 18세 이상 일반성인 1,000명을 대상으로 전문사회조사기관의 온라인패널을 통해 2014년 3-4월 33일간 웹설문조사를 실시하였고, 2013년 국가도서관통계를 분석하였다. 연구결과 우리나라 성인들의 공공도서관 방문은, 인구가 많은 대도시 지역에 거주하는 독서량이 많은 개인이 일상적으로 쉽게 접근할 수 있는 중소규모의 새로 건립된 공공도서관이 있고, 이용자 개개인의 요구에 부응할 수 있는 인적 자원이 충분하게 확보되어 있을 때 더 빈번히 이루어지고 있는 것으로 나타났다. 본 연구결과를 토대로 향후 공공도서관 건립 및 서비스 개선을 위한 정책적 제안을 제시하였다.

• 한국가정과교육학회지
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• 제31권4호
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• pp.129-147
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• 2019

본 연구는 고등학생을 대상으로 한 '건강한 커플관계'교육이 관계형성능력과 결혼 가치관에 미치는 영향을 알아보는데 목적이 있다. 연구 목적 달성을 위해 연구자가 개발한 '건강한 커플관계'교육을 2018년 9월 1일부터 11월 3일까지 8주간 두 개의 고등학교 수업에 각각 실행한 후 그 효과를 분석하였고 그 결과는 다음과 같다. 첫째, 고등학생을 위한 '건강한 커플관계'교육은 가정과의 교과역량인 관계형성능력을 향상시키는데 효과가 있었다. A그룹(S고등학교)은 '의사소통', '갈등해결' 영역과 '관계형성능력' 전체의 점수에서 통계적으로 유의미한 차이를 나타냈다. 인원수가 적어 Wilcoxon 부호-서열 검증을 실시한 B그룹(세종시 캠퍼스형 공동 교육과정)은 '관계형성능력'의 전체 및 하위 영역(의사소통, 자기이해, 갈등해결, 공감)의 점수가 통계적으로 유의하지는 않았지만 모두 향상되었다. 둘째, 고등학생을 위한 '건강한 커플관계' 교육은 고등학생의 결혼 가치관에 일부 긍정적인 영향을 미쳤다. A그룹(S고등학교)에서는 '결혼 가치관'이 유의미하게 긍정적으로 변화하였지만, B그룹(세종시 캠퍼스형 공동 교육과정)에서는 유의미한 차이가 나타나지 않았다. 결론적으로 '건강한 커플관계'교육은 고등학생들이 건강한 커플관계 형성을 위한 지식과 기술을 습득하고 자신의 삶과 연결하여 깊이 있게 탐구해 봄으로써 가정과 교과역량인 '관계형성능력'을 함양하고 결혼에 대한 이해의 폭을 넓혀 긍정적인 가치관을 형성하는데 도움을 줄 수 있다.

• 생물정신의학
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• 제27권1호
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• pp.18-26
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• 2020

Objectives The aim was to find effective vectorization and classification models to predict a psychiatric diagnosis from text-based medical records. Methods Electronic medical records (n = 494) of present illness were collected retrospectively in inpatient admission notes with three diagnoses of major depressive disorder, type 1 bipolar disorder, and schizophrenia. Data were split into 400 training data and 94 independent validation data. Data were vectorized by two different models such as term frequency-inverse document frequency (TF-IDF) and Doc2vec. Machine learning models for classification including stochastic gradient descent, logistic regression, support vector classification, and deep learning (DL) were applied to predict three psychiatric diagnoses. Five-fold cross-validation was used to find an effective model. Metrics such as accuracy, precision, recall, and F1-score were measured for comparison between the models. Results Five-fold cross-validation in training data showed DL model with Doc2vec was the most effective model to predict the diagnosis (accuracy = 0.87, F1-score = 0.87). However, these metrics have been reduced in independent test data set with final working DL models (accuracy = 0.79, F1-score = 0.79), while the model of logistic regression and support vector machine with Doc2vec showed slightly better performance (accuracy = 0.80, F1-score = 0.80) than the DL models with Doc2vec and others with TF-IDF. Conclusions The current results suggest that the vectorization may have more impact on the performance of classification than the machine learning model. However, data set had a number of limitations including small sample size, imbalance among the category, and its generalizability. With this regard, the need for research with multi-sites and large samples is suggested to improve the machine learning models.