• Journal of Welding and Joining
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• 제11권2호
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• pp.27-41
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• 1993

The estimation of nugget sizes was attempted by utilizing the artificial neural networks method. Artificial neural networks is a highly simplified model of the biological nervous system. Artificial neural networks is composed of a large number of elemental processors connected like biological neurons. Although the elemental processors have only simple computation functions, because they are connected massively, they can describe any complex functional relationship between an input-output pair in an autonomous manner. The electrode head movement signal, which is a good indicator of corresponding nugget size was determined by measuring the each test specimen. The sampled electrode movement data and the corresponding nugget sizes were fed into the artificial neural networks as input-output pairs to train the networks. In the training phase for the networks, the artificial neural networks constructs a fuctional relationship between the input-output pairs autonomusly by adjusting the set of weights. In the production(estimation) phase when new inputs are sampled and presented, the artificial neural networks produces appropriate outputs(the estimates of the nugget size) based upon the transfer characteristics learned during the training mode. Experimental verification of the proposed estimation method using artificial neural networks was done by actual destructive testing of welds. The predicted result by the artifficial neural networks were found to be in a good agreement with the actual nugget size. The results are quite promising in that the real-time estimation of the invisible nugget size can be achieved by analyzing the process variable without any conventional destructive testing of welds.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2003년도 한국우주과학회보 제12권2호
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• pp.48-48
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• 2003

A precision orbit determination (POD) system of low Earth orbiter using the GPS dual frequency measurements has been developed. It is an option of KOMPSAT-2 POD process system. In this research, the orbit determination using the real dual frequency carrier phase measurements of the SAC-C satellite was conducted to verify KOMPSAT-2 POD system reliability. The SAC-C satellite is an international cooperative mission between NASA, the Argentine Commission on Space Activities (CONAE), Centre National d'Etudes Spatiales (CNES or the French Space Agency), Instituto Nacional De Pesquisas Espaciais (Brazilian Space Agency), Danish Space Research Institute, and Agenzia Spaziale Italiana (Italian Space Agency). The SAC-C was launched at November 21, 2000. The altitude of SAC-C is 702 km and it carries a TurboRogue III GPS and four high gain antennas developed by the JPL. The receiver is able to generate the dual frequency code and carrier phase data. Double-differenced carrier phase measurements were formed using 25 IGS stations. The data were sampled at 30 seconds interval. Fully dynamic approach was adopted for POD. The POD results were compared with those of JPL using GOA n software. The comparison verifies that deci-meter level 3D position accuracy of low Earth orbiting satellite could be achieved. The POD system has been developed successfully.

• 한국운동역학회지
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• 제16권4호
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• pp.105-113
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• 2006

The purpose of this study was to analyze the joint torque of triple segmental system in golf driver swing. For this purpose, joint torque were calculated. In order to determine the load on the lumbar region, a triple segmental system was set for wrist, left shoulder and lumbar, torque working on the lumbar region were estimated. For this study, a total of 7 professional golfers were sampled, and then, their driver swings were recorded with two high-speed digital video cameras (180 frames/sec.) to be synthesized into 3-dimensional images and coordinated. Then, Eular's equation was used to produce some kinematic data, which were used to calculate joint torque with Newton's function. All data were calculated using LabVIEW 6.1 graphic program. The results of this study can be summarized as follows; It was found that the joint torque was generated in the direction opposite the target on wrist and shoulder during down swing, while in the direction towards the target on the lumbar region. During impact and release, the torque on the wrist joint was converted from the direction opposite the target to the direction towards the target, while the torque on the lumbar region was generated vice versa. The joints on the club-arm-shoulder were generated in the opposite direction at the beginning of down swing when the torque on the thorax-pelvis began to be generated, and then, the torque on the thorax-pelvis began to lower, while that on the club-arm-shoulder began to increase. Thus, a rapid decrease of the torque on the lumbar region linked to the low trunk acted to increase moment and joint torque on the arm-club region.

• 한국보건간호학회지
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• 제6권1호
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• pp.15-24
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• 1992

This study was conducted to follow the patient referral system operated from the primary health care facilities to the hospital in a rural area of Korea. The subject for this study was sampled from a community health development project carried out by the Korea University in Yeoju Kun, Kyonggi Province. The data of referred patients from primary health care facilities were collected during the period from January 1989 to December 1989. The data was sorted out by a computer system using Database package. The results of this study were summarized as follows: 1. Characteristics of the referred patients were: males $32.0\%$. and females $68.0\%$. The more elderly of the patients visited to the hospital after having been referred there by CHPs or public physicians, $25.9\%$ has been to hospital on at least one previous occasion as against $74.1\%$ for whom it was there first visit. 2. The majority of patients who were referred to a hospital where: medicine $44.3\%$ and orthopedics$16.4\%$, major diseases were : diseases of digestive system $(21.3\%)$ ; symptoms and ill defined conditions $(17.3\%)$ ; diseases of the muscular skeletal system and connective tissue$(14.2\%)$. chronic illness was $82.0\%$ and acute illlness was $18.0\%$. 3. From Community health practitioners more patients referred than the public physicians. Categoris of diseases of the referred patients were different between community health practitioners and public physicians. Due to the. respective differences between the medical restrictions put on the nursing staffs at the community health practitioners and public physicians. From this study it was recommended to define the reason of differences between ~he two groups in futher study. Study as to 1) why one group should be referring more for hospital treatment than the other. And 2) why the two agencies should be referring different diseases.

• 환경영향평가
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• 제20권1호
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• pp.1-11
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• 2011

This study was carried out to suggest the baseline data necessary for vegetation restoration at riverine wetland within stream corridor. We used the prevalence index for wetland assessment by applying the method of weighted averages with index values based on five hydrophyte indicator status as defined by estimated probability occurred in wetland. We selected near nature and urbanized reach of Gap and Yanghwa streams as experimental site. Although two sites have some different disturbance and characteristics of watershed, they showed that similarity of vegetation community including three dominant species - Salix koreensis, Phragmites communis, Miscanthus sacchariflorus - was very high. But in case of Yanghwa stream, various kinds of emergent plants along wetted condition were distinctly occurred, resulted from difference of hydrological regime and substrate, etc. Degree of naturalness of vegetation at the sampled areas indicated that near nature area of Gap stream and all area of Yanghwa stream were fitted as riverine wetland, while urbanized area of Gap stream has changed into upland condition. In conclusion assessment system using prevalence index would be considered an effective method for evaluating of natural states of riverine wetland, but further integrated consideration of physical, hydrological, and biological factors of stream process, and also with considering the difference between those qualitative data of vegetation community.

• 한국농공학회지
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• 제39권2호
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• pp.113-123
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• 1997

This study was initiated to build runoff plots, install soil and water quality monitoring systems and collect background data from the plots and neighboring soils as the 1st year study of a 5 year project to assess soil quality and develop the management practices for environmentally sound agriculture in mountainous soils. Eleven $3{\times}15m$ runoff plots and monitoring systems were installed at a field of National Alpine Agricultural Experiment Station to monitor soil quality and discharge of nonpoint source pollutants. Corn and potato were cultivated under different fertilizer, tillage and residue cover treatments. The soil has a single-layered cluster structure that has a relatively good hydrologic properties and can adsorb a large amount of nutrient. Concentrations of T-N, $NH_4$-N, and $NO_3$-N of surface soil sampled in the winter were relatively high. Runoff quality in the winter and thawing season in the spring was largely dependent on surface freezing, snow accumulation, temperature, surface thawing depth and so on. Runoff during the thawing season caused serious soil erosion but runoff quality during the winter was relatively good. Serious wind erosion from unprotected fields after the fall harvest were obserbed and best management practices to reduce the erosion need to be developed.

• 한국멀티미디어학회논문지
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• 제19권1호
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• pp.68-79
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• 2016

Electromyographic (EMG) signals have been widely used as motion commands of prosthetic arms. Although EMG signals contain meaningful information including the movement intentions of human body, it is difficult to predict the subject's motion by analyzing EMG signals in real-time due to the difficulties in extracting motion information from the signals including a lot of noises inherently. In this paper, four Ag/AgCl electrodes are placed on the surface of the subject's major muscles which are in charge of four upper arm movements (wrist flexion, wrist extension, ulnar deviation, finger flexion) to measure EMG signals corresponding to the movements. The measured signals are sampled using DAQ module and clustered sequentially. The Fuzzy C-Means (FCMs) method calculates the center values of the clustered data group. The fuzzy system designed to detect the upper arm movement intention utilizing the center values as input signals shows about 90% success in classifying the movement intentions.

• 전력전자학회논문지
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• 제8권5호
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• pp.375-380
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• 2003

기존의 속도센서가 없는 유도전동기의 고정자자속 기준제어에서 추정된 속도가 이산화 될 때, 이산화에 의한 모델링오차 때문에 회전자속도 추정에 오차가 발생한다. 이 오차는 저역통과필터에 의해 제거되지만 추정된 속도는 과도상태에서 지연이 발생해서 약계자영역으로의 천이가 지연되는 문제가 발생하게 된다. 본 논문에서는 기존의 고정자자속 기준제어 속도 센서리스 시스템의 약계자영역에서 추정된 속도의 지연으로 발생하는 문제점을 고찰하고 또한 루엔버거관측기를 사용하여 정확한 속도 추정을 학 수 있는 방법을 제안한다.

• 한국보건간호학회지
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• 제16권1호
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• pp.1-12
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• 2002

This study, aimed to categorize pattern of impatient's families in the ICU and to provide useful data for development of family-supportive program was conducted from June, 12 to Aug., 28, using Q-method. After reviewing the literature the researcher proceeded to interview 4 impatient's families in the ICU, developed the statement from consisting of 38 items, and then 30 impatient's families in the ICU were sampled. The collected data were coded after having been scaled from 1 to 9 points, and analyzed using the PC QUANL program. Three types were identified; The first type focused on self-regret about the impatient, the second type of families had some concerns for their health, and the third type was thinking of preparing for their future-lives, such as insurance and savings. It was common to feel powerlessness, regret, compassion, grief and anxiety in all types. They wanted to be given some information, the prognosis of patient and the way to overcome. The study will offer better understanding for family-centered approach and be useful for the system of orientation about impatients and their families.

• Journal of Community Nutrition
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• 제1권2호
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• pp.133-139
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• 1999

The purpose of this survey was to investigate eating habits, life styles and nutritional care of diabetic outpatients and to provide basic data for developing individualized nutritional care and diabetic education programs. This survey was carried out by nutritional counseling with a questionnaire and checking medical record. Information about the general characteristics of the subjects, eating habits, health-related life styles and attitude and perception of subjects to diet therapy was gathered from 200 randomly-sampled diabetic outpatients at a University Hospital located in Inchon. All data were analyzed by Statistical Analysis System(SAS) software. The results are summarized as follows : Female subjects were 63.5% of total subjects and 65.5% of total subjects were 50 years or more. The average Body Mas Index(BMI) of male and female subjects were 23.06kg/㎡ and 25.02kg/㎡ respectively and 44% of all subjects wee obese. Among subjects, type II diabetic patients were 81.0% and 82.5% of subjects had suffered from diabetes for more than one year. Also 41% subjects had diabetic history in their family. More than half of the subjects had nutrition education concerning diabetes. Also 75.5% of them thought that nutrition education was effective. The most important guideline in diet therapy was to eat cooked rice with dietary fiber-rich grains. Therefore, it might be necessary to develop nutrition education program adjusted according to diabetic patient's needs and life styles, which may increase feasibility of self-care and implementation of management guidelines.