• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.2
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• pp.353-368
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• 2023

The four wing unmanned aerial vehicle owns the characteristics of small size, light weight, convenient operation and well stability. But it is easily disturbed by external environmental factors during flight with these disadvantages of short endurance and poor attitude solving ability. For solving these problems, a microprocessor based on STM32 chip is designed and the overall development is completed by the resources such as built-in timer and multi-function mode general-purpose input/output provided by the master micro controller unit, together with radio receiver, attitude meter, barometer, electronic speed control and other devices. The unmanned aerial vehicle can be remotely controlled and send radio waves to its corresponding receiver, control the analog level change of its corresponding channel pins. The master control chip can analyze and process the data to send multiple sets pulse signals of pulse width modulation to each electronic speed control. Then the electronic speed control will transform different pulse signals into different sizes of current value to drive the motor located in each direction of the frame to generate different rotational speed and generate lift force. To control the body of the unmanned aerial vehicle, so as to achieve the operator's requirements for attitude control, the PID controller based on Kalman filter is used to achieve quick response time and control accuracy. Test results show that the design is feasible.

• The Korean Journal of Nuclear Medicine Technology
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• v.27 no.1
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• pp.23-28
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• 2023

Carbon materials are widely used in many areas of our lives. A fiber having a carbon content of 90% or more obtained by heating an organic fiber precursor is referred to as a "carbon fiber". Carbon fibers are currently used in the medical market to manufacture radiation transmission device parts, artificial joints, and medical aids, as many developments have been made to utilize carbon fibers' characteristics such as light weight, radiation permeability, biocompatibility, high strength, high heat resistance, thermal conductivity, and electrical conductivity. In order to maintain body temperature and increase immunity in long-lasting nuclear medical examination and treatment through the idea of convergence of carbon materials and radiation technology, the quality of medical services can be improved by utilizing carbon materials. We should be aware of the domestic carbon-based medical device industry and make efforts to contribute to the development of medical devices. As a radiation expert, we should try to use our skills and experience to find items that can be fused with medical devices to develop various nuclear medical examination fields and radiographic examination fields that can be widely applied. We should actively engage in future technology development and carbon material research to strengthen the global competitiveness of the domestic medical device industry and improve the quality of medical services.

• Korean Journal of Poultry Science
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• v.24 no.3
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• pp.117-126
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• 1997

This study was conducted to estimate the hatching and growing performance, and heterosis of Korean Native Chicken(KNC), Rhode Island Red(RIR) and KNC XRIR crossbred. A total of 1,274 female pullets were produced from KNC, RIR and KNC x RIR crossbred kept in National Live-stock Research Institute, Korea. The experiment was conducted for 20 weeks from Sep. 2, 1995 to Jan. 20,1996. Hatchabilities of KNC dark brown strain x RlR(DR), KNC light brown strain x RlR (LR) and KNC dark black strain x RlR(BR) were 77.3%, 73.6% and 72.5%, respectively. Viabilities up to 20 weeks of age were not significantly (P>0.05) different among purebreds and crossbred. Body weights of DR, LR and BR were 1,890 g, 1,849 g and 1,967 g, respectively, at 20 weeks of age. The feed conversion ratio(feed /gain) of DR, LR, and BR were 5.88, 6.07 and 5.87, respectively, up to 20 weeks of age. Average shank lengths of DR, LR and BR were 97.1 mm, 98.9 mm and 99.4 mm, respectively, at 20 weeks of age. The heterosis effects were estimated to be -0. 48%, and 12.58%, respectively, in fertility and hatchability. Up to 20 weeks of age, the heterosis effects were estimated to be 0.07%, 13.49%, -5.77%, and 3.52% in viability, body weight, feed conversion ratio, and shank length, respectively.

• Korean Journal of Poultry Science
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• v.24 no.3
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• pp.127-137
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• 1997

This study was conducted to estimate the laying performance and heterosis of Korean Native Chicken(KNC), Rhode Island Red(RIR), and KNC x RIR crossbreds A total of 1,274 female pullets were produced from KNC, RIR and RIR crossbreds in National Livestock Research Institute, Korea. The experiment was conducted for 2O~64 weeks from Jan 20. to Nov.25, 1996. The age at first egg of crossbreds were 144.1~148.7 days. The first egg weight of crossbreds was 39. 4~40.3 g, and body weights at first egg of KNC dark brown strain x RlR(DR), KNC light brown strain x RlR(LR) and KNC dark black strain x RlR(BR) were 1,943 g, 1,925 g and 2,044 g, respectively. During the laying period the average viability of crossbreds was 96.6~98.3%. The hen-day egg production of crossbreds were 111.1~113.O eggs at 40 weeks of age, and 223.5~227.5 eggs at 64 weeks of age, respectively. The hen-day egg production peaks were 78.2~80.1% in KNC, and 85.8~87.5% in crossbreds. The heterosis were estimated to be 3.61%, 9.21%, 4.78%, 2.97% and -1.63% for the first egg days, body weights at first egg, layer viability, hen-day egg production, and feed conversion ratio, respectively.

• Korean Journal of Community Nutrition
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• v.17 no.5
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• pp.652-663
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• 2012

The purpose of this study was to assess the physical activity level of Korean farmers to establish estimated energy requirements during the off-season. Subjects were 90 healthy males (n = 25) and females (n = 65). Body weight, height and body fat and muscles of subjects were measured. The prevalence of obesity among farmers was 56.7% according to the BMI. The farmers spent about 18 hours 7 minutes (75.5%) in sleeping and resting. The farmers spent about 19 hours 56 minutes (83.1%) out of 24 hours (one day) in "sedentary activities" and spent about 3 hours 56 minutes (16.4%) in "light activities". Physical activity level (PAL, activity coefficient) of female farmers was 1.42 which was not significantly higher than that (1.37) of male farmers. Estimated energy requirements (EER) for farmers who were different in age groups and gender were calculated. For example, the EERs for male and female farmers were 2190 kcal/day and 1712 kcal/day, respectively. The daily energy intakes of male and female farmers were 1803 kcal/day and 1610 kcal/day, respectively. The EER of male farmers was 2190 kcal/day which was significantly higher than that (1803 kcal/day) of the recommended daily energy intake of male farmers. The results of this study suggest that estimated EER of farmers should be modified according to seasonal workload and energy balance of farmers should be evaluated to prevent obesity.

• Journal of Advanced Marine Engineering and Technology
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• v.18 no.5
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• pp.56-67
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• 1994

The installation methods of diesel engines in ships would be largely classified into two groups : one is the direct mounting system fixing engine directly into double bottom of the hull, and the other is the resilient mounting system having vibration absorbers between engine and ship body such as rubber plate to prevent shocks or vibration transmission. The direct mounting system is generally used for large-sized low speed diesel engines, because the resilient mounting system has difficulties in reducing the natural frequency of engine itself under normal speed. On the contrary, the resilient mounting system is often used for medium or high speed engines for marine propulsion and generator that have light weight and high revolution speed. Recently, it is even applied to engines having relatively low speed(300-400rpm) for fishing boats. Although many researches for the resilient mounting system have been carried out, many problems in applying these results directly to marine vessels because most of these have been used for automobiles. Up to now we have had to depend on the professional foreign company in design and the supply of parts for the resilient mounting system of marinediesel engines utterly. In preseut study, the exciting forces of engines effecting to resilient mounting were examined, and patterns of vibration and evaluation procedure for force transmission from resilient mounting to the body of hull were established. Also, these results were applied to the analysis of free and forced vibration for the rubber-type resilient mounting systems of marine diesel engines. Besides, after changing the various design parameters, such as locations, angles, dynamic characteristics and the number of resilient mountings, the influences on resilient mounting system were also examined.

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.4
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• pp.5-11
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• 2007

The future combat system is likely to be studied and developed in terms of enhancing both firepower and mobility simultaneously. Increased firepower often necessitates a heavier firing system. In return, the body of the vehicle needs to be light-weight in order to improve the mobility of the whole system. For this reason, in the areas of weapons systems such as the tank and self-propelled artillery, a number of studies attempting to develop designs that reduce recoil force against the body of the vehicle are being conducted. The current study proposes a tank construction that has a mass-spring-damper system with two degrees of freedom. A tank structure mounted with a specific soft recoil system that was implemented using a soft recoil technique and another tank structure based on a general recoil technique were compared to each other in order to analyze the recoil forces, the displacements of recoil, and the firing intervals when they were firing. MATLAB-Simulink was used as a simulating tool. In addition, the relationship between the movement of the recoil parts and the positions of the recoil latches in each of the two structures were analyzed. The recoil impact power, recoil displacement, firing interval, and so on were derived as functional formulas based on the position of the recoil latch.

• Korean Journal of Health Education and Promotion
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• v.12 no.1
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• pp.111-127
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• 1995

This study was designed to investigate the relationships between children's physical growth and health and their raising conditions and to find out the important conditions to improve their physical growth and health. The rasing conditions were classified into three major parts; i. e., family conditions, conditions of nutrition up-taking, and conditions of rest or sleep and exercise or play. Then, the questionnaire including the items to survey these three areas of raising condition and the items to evaluate the health status were given to children' mothers or fathers and filled up by them. The data of their 4 anthropometric measures; body weight, stature, sitting height and chest girth, were also collected from their latest records of health examination. The data of health status were converted to health scores representing 6 domains of health; digestive organs, respiratory organs, auto-nerve systems, fatigue, others and health as a whole. Then, correlations of raising conditions were determined with four antropometric measures and 6 health scores as criterion variables. Then, number of families to live together, and child's birth order in the domain of family conditions, habits of unbalanced diet, eating frequency of eggs, fruits, green and yellow vegetables, light colored vegetables, milk products in the domain of nutrition up-take, and the time for study at home, the place for play, the number of friends to play with together, the hours for playing out of door, the hours for playing sports, and the hours to move their body for assisting house keeping were picked out to investigate their relationships with physical growth and health status. Then, their habits of unbalanced diet and eating frequency of eggs, green or yellow colored vegetables, and milk products were found more influential conditions and more over, birth order, the time for study at home, the time to play out of door showed moderate degree of connection with physical growth and health status in early childhood.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.7
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• pp.760-766
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• 2014

This paper represents a portable robot for use in the welding process of the double hulls in shipbuilding yards. It has 5 degrees of freedom and 3kg of payload. Its body weight is 17.3 [kg] so that human workers can carry it by hand to the work place. Its body is mainly made of magnesium and aluminum alloys. Since the robot is placed about 25m apart from its controller, EtherCAT is adopted for reliable connection between the robot and controller through a single light cable. RTX real-time kernel and KPA EtherCAT master are used to control the robot on a Windows XP environment. The performance of the developed robot is satisfactory to the requirement in welding tasks of U-type cells in shipbuilding yards.

• The Journal of Pediatrics of Korean Medicine
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• v.30 no.3
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• pp.108-120
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• 2016

Objectives The purpose of this study is to investigate Korean clinical studies on treatment of childhood obesity and to propose for better treatment options for childhood obesity. Methods Based on RISS, KISS, OASIS, KMbase with the keyword 'childhood obesity', 'child obesity', 'obese child', 'overweight child', total of 21 randomized controlled trials (RCTs), 11 single clinical studies, 3 chart reviews and 3 case reports have been found, and were analyzed. Results and Conclusion 1. Some study subjects were classified based on their sex - only men or women in a group or sometimes both. Another way of classify the study subjects were based on their age - preschooler, primary school students, middle school students, and high school students. The diagnostic criteria of the subjects were BMI (body mass index), Body fat percentage, Obesity index, Weight and unknown criteria. 2. The treatments used in 38 studies were exercise alone, education alone, both exercise and education or herbal therapy. The 7 studies that used herbal therapy as part of their study intervention had a study group with herbal intervention only and the other 2 study group with herbal treatment in addition to exercise and education. 3. 9 studies included herb medicines, electroacupuncture, auricular acupuncture, cupping, aroma massage, infrared light, and abdomen pad. Herb medications used in 5 studies included Chegameuiin-tang 2 kinds, Sobieum, Biman-tnag, and I-razin. 4. The methods of assessment used in 38 studies were classified by 7 categories and anthropometry parameters which is the basic methods are used in all studies 5. Almost studies (29 studies in all 38 studies) were using anthropometric parameters results on significantly effectiveness of childhood obesity. 6. More studies are needed to prove true effectives from various treatments, especially herbal therapy for childhood obesity.