• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.2
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• pp.239-247
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• 2018

Adaptive Beamforming (ABF) algorithm, which is a typical jammer suppression algorithm, guarantees the performance on the assumption that the jamming characteristics of the TDS (Training Data Sample) are stationary, which are obtained immediately before and after transmitting the pulse signal. Therefore, effective jammer suppression can not be expected when the jamming characteristics are non-stationary. In this paper, we propose a new jammer suppression algorithm, of which power spectrum fluctuates fast. In this case, we assume that the location of the jammer station is fixed during the processing time. By applying the MPM (Matrix Pencil Method) to the jamming signal in TDS, we can estimate jammer parameters such as power and incident angle, of which the power will vary fast in time or range bins after TDS. Though we assume that the jammer station is fixed, the estimated jammer's incident angle has an error due to the noise, which degrades the performance of the jammer suppression as the jammer power increases fast. Therefore, the jammer's incident angle should be re-estimated at each range bin after TDS. By using the re-estimated jammer's incident angle, we can construct new covariance matrix under the non-stationary jamming environment. Then, the optimum weight for the jammer suppression is obtained by inversing matrix estimation method based on the matrix projection with the estimated jammer parameters as variables. To verify the performance of the proposed algorithm, the SINR (signal-to-interference plus noise ratio) loss of the proposed algorithm is compared with that of the conventional ABF algorithm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.9
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• pp.1871-1880
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• 2011

In this paper, a controller for two wheeled inverted pendulum robot, i.e., Segway type robot that is a convenient and easily handled vehicle is designed to have more stable balancing and faster velocity control compared to the conventional method. First, a widely used PID control structure is applied to the two wheeled inverted pendulum robot and proper PID control gains for some specified weights of users are obtained to get accurate balancing and velocity control by use of experimental trial-and-error method. Next, neural network is employed to generate appropriate PID control gains for arbitrarily selected weight. Here the PID gains based on the trial-and-error method are used as training data. Simulation study has been carried out to find that the performance of the designed controller using the neural network is more excellent than the conventional PID controller in terms of faster balancing and velocity control.

• Korean Journal of Community Nutrition
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• v.5 no.1
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• pp.50-62
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• 2000

This study was conducted with 20 female gymnasts to examine the relationship between eating patterns, diet menstrual function and hematological status. According to the baseline data a nutrition counseling and education program was developed and evaluated improved the nutritional status and health of female gymnasts. Mean body weight at the onset of the study was 42.1$\pm$7.0kg and was reduced to 41.8$\pm$6.1kg after the nutrition counseling and education program. The percent of body fat was significantly reduced from 13.9$\pm$3.7% to 13.1$\pm$3.1%(p<0.01) skinfold thickness of subscapular and thighs was reduced significantly(p<0.01, p<0.05) Mean daily intake levels of energy, protein calcium iron thiamin riboflavin and niacin were significantly elevated after the nutrition counseling and education program but were lower than the Recommenced Dietary Allowances. For the nutrition knowledge and food habits, the posttest mean scores showed a significant increase. The hematological status(hematocrit, serum ferritin) and the early follicle level of estradiol were elevated to a mild degree although it was not significant,. The follicular stimulating hormone level was elevated significantly(p<0.01) Gymnastica has been one of the sports implicated by the medical profession as having probable detrimental effects. The implications of such training to childs growth and maturation have yet to be determined . Most female athletes, however, experience poor nutritional status and delayed puberty The priorities were to prepared a more effective nutrition program and education material status and delayed puberty. The priorities were prepared a more effective nutrition program and educational material for athletes coaches and adminstrators to prepare guidelines for the team physicians and coaches to follow for the physical and physiological examinations of female athletes.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.2
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• pp.113-121
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• 2011

In this paper, we proposed the method automatically to match areal feature based on similarity using spatial information. For this, we extracted candidate matching pairs intersected between two different spatial datasets, and then measured a shape similarity, which is calculated by an weight sum method of each matching criterion automatically derived from CRITIC method. In this time, matching pairs were selected when similarity is more than a threshold determined by outliers detection of adjusted boxplot from training data. After applying this method to two distinct spatial datasets: a digital topographic map and street-name address base map, we conformed that buildings were matched, that shape is similar and a large area is overlaid in visual evaluation, and F-Measure is highly 0.932 in statistical evaluation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.4
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• pp.326-333
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• 2015

A turbo fan engine performance analysis program combined with a particle swarm optimization(PSO) has been developed to optimize the major design parameters of the combat aircraft gas turbine engine. The optimized parameters includes bypass ratio, fan pressure ratio, high pressure compression ratio and burner exit temperature. The objective parameters have been determined using a multi-objective function consisting of the net thrust and specific fuel consumption along a weight function. The basic model for the combat aircraft gas turbine engine has been selected as the F404 turbofan engine which is widely used in the combat aircraft, F-18 and Korean high level training aircraft, T-50. The optimal conditions of four parameters have been obtained for various design conditions.

• The Journal of Industrial Distribution & Business
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• v.5 no.2
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• pp.29-35
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• 2014

Purpose - The study aimed to evaluate the market opportunities and constraints confronting resource-poor pig farmers in South Africa. Research design, data, and methodology - Information was collected from 292 households in three municipalities through interviews with key informants. The data collected included socio-economic characteristics, major market channels, prices for different pig classes, average weight of the pigs on sale, number of pigs sold annually, and preferred meat quality attributes. Results - In Ngqushwa, 96% of respondents sold pigs as compared to Elundini (81%) and Ntabankulu (65%). Less resource-poor households and those with market-oriented production had large herdsizes (P < 0.05) when compared to more resource-poor farmers. The probability of selling pigs was high for the backyard production system and educated farmers. For all farmers, opportunities included high pork demand, good prices, employment creation, and a niche market for organically produced indigenous pork. Constraints include disease, feed shortages for large herds, distances to formal markets, lack of training, and drugs. Conclusions - Constraints outnumbered opportunities for the resource-poor pig farmers.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.321-324
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• 2001

The robot soccer simulation game is a dynamic multi-agent environment. In this paper we suggest a new reinforcement learning approach to each agent's dynamic positioning in such dynamic environment. Reinforcement Beaming is the machine learning in which an agent learns from indirect, delayed reward an optimal policy to choose sequences of actions that produce the greatest cumulative reward. Therefore the reinforcement loaming is different from supervised teaming in the sense that there is no presentation of input-output pairs as training examples. Furthermore, model-free reinforcement loaming algorithms like Q-learning do not require defining or loaming any models of the surrounding environment. Nevertheless it can learn the optimal policy if the agent can visit every state-action pair infinitely. However, the biggest problem of monolithic reinforcement learning is that its straightforward applications do not successfully scale up to more complex environments due to the intractable large space of states. In order to address this problem, we suggest Adaptive Mediation-based Modular Q-Learning(AMMQL) as an improvement of the existing Modular Q-Learning(MQL). While simple modular Q-learning combines the results from each learning module in a fixed way, AMMQL combines them in a more flexible way by assigning different weight to each module according to its contribution to rewards. Therefore in addition to resolving the problem of large state space effectively, AMMQL can show higher adaptability to environmental changes than pure MQL. This paper introduces the concept of AMMQL and presents details of its application into dynamic positioning of robot soccer agents.

• Korean Journal of Veterinary Research
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• v.43 no.4
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• pp.683-688
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• 2003

Caffeine (1,3,7-trimethylxanthine), a central nervous system stimulant, is contained in various foods, beverages and over-the-counter medications. Sulfadimethoxine (SDM) is one of the anti-thyroid agents and induces proliferation of thyroid capsule in two stage thyroid carcinogenesis model using N-bis(2-hydroxypropyl)nitrosamine (DHPN). In this study, we examined the effect of caffeine on fibrous proliferation of thyroid capsule in DHPN and SDM-treated rats. Five-week-old male F344 rats were given a single subcutaneous injection of DHPN (2,800 mg/kg, body weight). Starting one week thereafter, SDM (1,000 ppm in drinking water) with or without caffeine (1,500 ppm in diet) was administered for 12 weeks. All animals were autopsied and histopathological examination of the thyroid glands was performed. Thyroid follicular proliferative changes were induced in all rats treated with DHPN+SDM. In addition, the proliferation of perithyroidal fibrous tissue and pleomorphic thyroid follicular cells within the capsule were observed in DHPN+SDM treated group. Caffeine would not be related to these lesions in this experimental condition. although pentoxifylline, a methyl xanthine derivative, has an anti fibrotic effects.

• Journal of Digital Convergence
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• v.12 no.7
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• pp.297-304
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• 2014

The present study was designed to investigate the effect of home based exercise program on balance recovery of stroke patients. In total, 20 participants were assigned to a control group(n=10) or exercise group(n=10) between September 2013 and December 2013. In addition to existing physiotherapy, the exercise group received home based exercise program consisting of weight transfer, training endurance, mobility, sensory retraining, lower limb exercise for 30 minutes, 2 times a week, for 8 weeks, every time for 30 minutes. Balance ability was assessed by measuring foot pressure(FP), limit of stability(LOS) and velocity sway(VS) by using Biorescue and by using the functional reaching test(FRT). To compare the improvement level of each group's balance ability, examination of independent sample T was done. Significant differences between control group and exercise group in LOS, VS of affect side and FRT were observed. This study showed that home based exercise program application was effective strategy on balance recovery in a post stroke population.

• Journal of Korean Biological Nursing Science
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• v.4 no.2
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• pp.59-68
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• 2002

The purpose of this study was to determine the effect of exercise program on natural killer cell cytotoxic activity(NKCA) in breast cancer patients who had been radiation therapy after surgery. The subjects in the experimental group consisted of 11 breast cancer patients, while the subjects in the control group consisted of 15. Subjects in the experimental group participated in exercise program for 8 weeks. Exercise program consisted of shoulder stretching, arm weight training and treadmill walking exercise. They started to exercise on treadmill for 20 minutes per day, 3 times a week at 40% of maximum heart rate, and increased intensity and duration of exercise so that they were running 30 minutes/day at 60% of maximum heart rate from the 3rd week to the 8th week. Natural killer cell cytotoxic activity were determined before and after the exercise program. For measuring the natural killer cell cytotoxic activity, 8ml to 10ml blood was collected from the subjects. Mononuclear cell was isolated by centrifuge of the blood and cultured by putting $Cr^{51}$, and reacted with target cell, K562 cell. Baseline demographic and medical data were compared between groups with the Fisher's exact test and Mann-Whitney U test. For effects of the exercise program, repeated measures ANOVA was used. The result was as follows; Natural killer cell cytotoxic activity(NKCA) in experimental group comparing with control group significantly increased after the exercise program in case of effector cell : target cell ratio is 100 : 1(p<0.05). The above result suggest that the exercise program for breast cancer patients undergoing radiation therapy after breast surgery may increase the natural killer cell cytotoxic activity.