• Journal of the Korean Society for Precision Engineering
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• v.19 no.1
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• pp.119-126
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• 2002

In this paper, we present a new approach based on an elitist genetic algorithm for the task of aligning the position of a robot gripper using CCD cameras. The vision-based control scheme for the task of aligning the gripper with the desired position is implemented by image information. The relationship between the camera space location and the robot joint coordinates is estimated using a camera-space parameter modal that generalizes known manipulator kinematics to accommodate unknown relative camera position and orientation. To find the joint angles of a robot manipulator for reaching the target position in the image space, we apply an elitist genetic algorithm instead of a nonlinear least square error method. Since GA employs parallel search, it has good performance in solving optimization problems. In order to improve convergence speed, the real coding method and geometry constraint conditions are used. Experiments are carried out to exhibit the effectiveness of vision-based control using an elitist genetic algorithm with a real coding method.

• Korean Journal of Human Ecology
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• v.20 no.3
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• pp.637-649
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• 2011

The purpose of this study was to analyze employees' practice levels and knowledge of sanitation at school foodservice operations, to examine the sanitation conditions of current school foodservice, and to suggest an effective sanitary training program. A questionnaire survey was conducted on a total of 578 subjects and 501 reponses were made available for this study. The collected data was analyzed using SPSS of windows. The main results can be summarized as follows: Training through handouts was the most effective (53.2%) and lack of time caused by overwork (57.1%) made the practice of sanitation training difficult. The degree of employees' perceptions of the necessity of sanitary training programs was marked at 4.18 points. According to the foodservice employees' evaluation about the knowledge of sanitation concerning the sanitary training program contents, the area of environmental sanitation (96.3%) was the highest while food poisoning control (72.9%) was lowest. Foodservice employees' practice levels was ranked above 4 points (out of 5 points) in 9 areas. Practice levels of cleaning and disinfection management were highest while that of safety management was lowest. About the food service employees' practice levels of sanitation, the degree of practice and the application of knowledge was 4.39 points. There was a significantly positive correlation between the practice level of sanitation and sanitation knowledge(p<.01). Thus, educational material needs to be standardized in order to improve employees' sanitation practice level.

• Journal of Biosystems Engineering
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• v.36 no.5
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• pp.377-383
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• 2011

This study proposed the new method of discerning the assembled parts and presuming the position of central point in a Cowl Cross Bar (CCB) using a Charge-Couple Device (CCD) camera attached to a robot in the auto assembly line. Three control points of an ellipse were decided by three reference points, which were equally distanced. The radii of these reference points were determined by the size of the object, and the repeated presumption secured the precise determination. The comparison of the central point of ellipse presumed by Randomized Hough Transform (RHT) with the part information stored in a database was used for determining the faulty part in an assembly. The method proposed in this study was applied for the real-time inspection of elliptical parts, such as bolt, nut hole and so on, connected to a CCB using a CCD camera. The findings of this study showed that the precise decision on whether the parts are inferior or not can be made irrespective of the lighting condition of industrial site and the noises of the surface of the part. In addition, the defect decision on the individual elliptic parts assembled in a CCB showed more than 98% accuracy within a 500-millisecond period at most.

• Korean Chemical Engineering Research
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• v.58 no.3
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• pp.390-395
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• 2020

For some processes with saturations, economical operating points are on the saturation edges. Traditional feedback controllers cannot be used to regulate such processes on the saturation edges because there are abrupt dynamics changes and no feedback information at saturations. Optimization-based methods such as the model predictive control can treat this control problem without difficulty when the saturation levels and dynamics are known and not varying. Otherwise, an adaptation scheme to track the saturation levels and dynamics should be included. Here, for very simple methods to treat this control problem, two control methods based on the recent slope seeking method and the relay feedback method are proposed. Their performances are evaluated with simulations applying them to a second order liquid level system with saturation. Simulations show that these proposed control methods can find and maintain operating point of the saturation edge under 5% relative error.

• Korean Journal of Cleft Lip And Palate
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• v.2 no.1_2
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• pp.15-22
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• 1999

It is well known that the postoperative skeletal instability after Le Fort I osteotomy for advancement of maxilla in the cleft patients is one of the major surgical problems. So we had tried to compare the amount of relapse after Le Fort I advancement surgery in the horizontal and vertical positional change, angular change of reference points between cleft patients and non-cleft patients. Longitudinal records of 10 consecutive cleft patients (test group) and 20 non-cleft patients (control group) were analyzed. Lateral cephalograms were taken preoperatively, immediately postoperatively, and 2, 6, 12 months postoperatively. We measured horizontal and vertical changes (ANS, PNS, AI) and angular change (SNA) of the reference points and lines. In the test group, horizontal relapse of ANS, PNS, AI point are 36.4%, 37.5%, 32.0% respectively at 12 months postoperatively. The vertical relapse of ANS, PNS, AI are 25.3%, 32.3%, 39.1% respectively at 12 months postoperatively. The angular change of SNA is 33.6% at 12 months postoperatively. In the control group, horizontal relapse of ANS, PNS, AI point are 23.8%, 30.2%, 21.7% respectively at 12 months postoperatively. The vertical relapse of ANS, PNS, AI are 22.7%, 27.3%, 25.1% respectively at 12 months postoperatively. The angular change of SNA is 22.2% at 12 months postoperatively. The cleft patients have a larger tendency of skeletal and dental relapse compared with non-cleft patients after Le Fort I surgery. So the oral and maxillofacial surgeons must keep in mind these facts in order to minimize the relapse phenomenon from the beginning of surgical planning to postoperative care.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.5
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• pp.465-474
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• 2007

This paper focuses on examining and evaluating results of the Korean Geodetic Datum 2002 (KGD2002) of the national horizontal network adjustment. To this end, 137 geodetic control points were independently observed by GPS technology. After processing all the observations, their results were compared with ones derived by the national network adjustment which was recently performed to determine new KGD 2002 coordinate sets over the national geodetic control points. The comparisons results showed that RMSE was ${\pm}2.7cm$ and ${pm}6.5cm$ in horizontal and vertical component in the case of GPS network, whereas RMSE was ${\pm}3.0cm$, in horizontal component in the case of EDM network.

• Korean Journal of Veterinary Research
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• v.38 no.1
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• pp.201-208
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• 1998

Piglets' diarrhea is one of the major causes of economic loss in Korean swine industry. To prevent this serious and persistant problem, we have developed systemic farm evaluation and analysis program. The program consists of the checklist and the computerized program. The items of the checklist are selected on the basis of various causative factors related with the piglets' diarrhea including sanitational status, nutritional management, or farm environment. The checklist is composed of 30 items including 6 factors on facility, 8 factors on environment, 6 factors on nutrition and 10 factors on sanitation, respectively. Minimum 1 to maximum 10 points was assigned to each item depending on level or status of farm. The scores calculated by sum of points obtained from each item could find out the problems which the farm was confronted with. To investigate the applicability of a program 150 swine farms raising over 500 heads were selected from 7 provinces throughout the country and surveyed. There were significant correlations between the piglets' diarrhea and the scores of the checklist. Based on above results we revised the checklist which consisted of 22 items including 5 factors on facility, 7 factors on environment, 3 factors on nutrition and 7 factors on sanitation. After that we composed a computerized diagram out of each point of an item which showed and indicated weak factors to be improved promptly. Our present study suggested that this newly established swine farm evaluation program would be a very efficient way to find out the problems and support the systemic control program of the piglets' diarrhea for swine farms.

• Korean Journal of Community Nutrition
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• v.29 no.4
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• pp.278-287
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• 2024

Objectives: This study investigates the relationship between smartphone usage and eating behavior among elementary school students. Methods: This survey was conducted on 4th- to 6th-grade students at elementary schools in Gangneung from September 6th to September 15th, 2023. Of the 129 copies of the questionnaire that were distributed to 5 schools, 66 copies (51.2%) were returned. Results: Compared to the nationwide statistics, the smartphone ownership rate of elementary school students in Gangneung was lower, but the rate of smartphone overdependence was higher. Smartphone dependence was 21.12 points for study subjects and 26.00 points for the overdependence risk group (Org). Compared to national statistics, the self-control failure factor was higher, so study participants in Gangneung City are thought to have great difficulty with self-control. The Org's weekend smartphone use time of 7.54 hours was significantly more than the general user group (Gug)'s 4.06 hours. The number of days in which the Org consumed late-night snacks per week was 2.92 days, and the Gug had 2.15 days, but the difference was not significant. Eating fast food showed a positive correlation with eating sweet food, eating fatty food, and eating heavily seasoned food. It was found that frequent consumption of fast food is closely correlated with unhealthy eating behavior. Weekend smartphone use time showed a significant positive correlation with smartphone dependence and the number of days late-night snacks consumed per week. Conclusions: Study participants in Gangneung are more dependent on smartphones than national statistics. Smartphone dependence had a negative correlation with healthy eating behavior and a correlation with average unhealthy eating behavior.

• Korean Chemical Engineering Research
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• v.50 no.5
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• pp.815-824
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• 2012

Extractive distillation system can be used when the components to be separated have close boiling points or form azeotropes. Extractive distillation is one of the most important and widely used separation methods in chemical process industry. The main disadvantage of the distillation is its high-energy requirements. Thermally coupled distillation system (TCDS) can provide significant savings in energy consumption and capital cost over the operation of sequences based on conventional distillation column. Despite such advantages of the thermally coupled distillation system, the process is not widely used in industry because control and operation of the column are difficult. In this study, we propose several control schemes for thermally coupled distillation system to overcome the difficulties and make the column stable when the process is confronted with feed disturbances. Profile position control scheme shows best control performance among the proposed control schemes.

• Journal of Fisheries and Marine Sciences Education
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• v.24 no.2
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• pp.224-233
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• 2012

Hazard Analysis and Critical Control Points (HACCP) is a systematic preventative approach for food safety and is generally used in food industry to identify potential food safety hazards. Recently, the Korean Ministry for Food, Agriculture, Forestry and Fisheries planed to applicate HACCP programs as an effective approach to food safety and protecting public health at the aquaculture farm of rainbow trout, Oncorhynchus mykiss. For the purpose, it need to identify what kinds of hazards are in the aquaculture farm. In the present study, we established Sanitation Standard Operating Procedures (SSOP), which addresses sanitation conditions and practices in the aquaculture farm. SSOP is essential prerequisite programs of HACCP to reduce or eliminate the risk of the hazards being realized. We anticipate that the HACCP programs of aquaculture farm will contribute to supply foods in safety to consumers.