• Korean Journal of Community Nutrition
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• v.4 no.2
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• pp.175-185
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• 1999

This study was conducted among the university students to investigate the effects of working in an daytime and studying in an evening class on dietary behaviors and nutrient intakes. A 24-hour recall method was used along with food frequency questionnaires. The subjects were composed of three groups : 172 were in the daytime calss regular student group(RS), 178 were evening class students without a job(ESWOJ), and 140 were evening class students with a job(ESWJ). An average age of the ESWJ was 31 years old, which was 9 years older than the RS and 7 years older than the ESWOJ. The types of the residence were significantly different among the groups ; were seif-boarding 74% of the ESWJ stayed at home while 47% of the RS were self-boarding and 61% of the ESWOJ. The survey shows that while a great majority of the RS and ESWOJ has breakfast and supper at home, about 10% and 17% of the ESWJ ate breakfast and supper, respectively, at the cafeteria in their work place. The most frequently skipped meal was the breakfast in all groups. Approximately 9% of the ESWJ tended to skip the breakfast, while 27% of the RS and 33% of the ESWOJ did. It turns out that the mose common reason why ESWJ skipped meals was due to a lack of time. About 71% of the ESWJ ate out more than once a week compared to 57% and 62% of the RS and ESWOJ, respectively. Approximately 30% of the ESWJ ate out more than once a week compared to 57% and 62% of the RS and ESWOJ, respectively. Approximately 30% of the ESWJ spent less than 10 minutes at meal time, showing a hurried eating habit. The results show that the ESWJ tended to eat a variety of food s and eat less instant foods, but drink coffee more often compared to the other two groups. The results also show that in all groups, the intakes of energy, Ca, and vitamin A were lower than the Korean Recommended Daily Allowances(RDA). In addition to these nutrients, protein, vitamin B1, vitamin $B_2$, and niacin were also lower than the RDA in all make students, and Fe was lower than the RDA in all female students. Among the deficient nutrients, vitamin A showed the lowest % RDA : 48% in the male and 64% in the female students. Among the deficient nutrients, vitamin A showed the lowest % RDA ; 48% in the male and 64% in the female students. The intakes of Ca, Fe, and niacin in the ESWJ were significantly greater than those in the RS and ESWOJ groups, and the vitamin C intake in the ESWJ was greater than that in the ESWOJ(p<0.01). In conclusion, university students in all three groups have a serious imbalance in the nutrient intakes, and the evening class students with a daytime job have unhealthy dietary behaviors in the light of high frequency of eating out and heavy coffee drinking, a rushed eating pattern, and therefore showing a strong need of proper nutritional education for them.

• Journal of KIISE:Software and Applications
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• v.30 no.9
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• pp.862-866
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• 2003

Traveling Salesman Problem(TSP) is a combinational optimization problem, Genetic Algorithm(GA) and Lin-Kernighan(LK) Heuristic［1］that is Local Search Heuristic are one of the most commonly used methods to resolve TSP. In this paper, we introduce ACS(Ant Colony System) Algorithm as another approach to solve TSP and propose a new pheromone updating method. ACS uses pheromone information between cities in the Process where many ants make a tour, and is a method to find a optimal solution through recursive tour creation process. At the stage of Global Updating of ACS method, it updates pheromone of edges belonging to global best tour of created all edge. But we perform once more pheromone update about created all edges before global updating rule of original ACS is applied. At this process, we use the frequency of occurrence of each edges to update pheromone. We could offer stochastic value by pheromone about each edges, giving all edges' occurrence frequency as weight about Pheromone. This finds an optimal solution faster than existing ACS algorithm and prevent a local optima using more edges in next time search.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.3
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• pp.306-315
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• 2012

In this study, storage stability of reduced sulfur compounds ($H_2S$, $CH_3SH$, DMS, $CS_2$, and DMDS) and $SO_2$ in sampling bags was investigated in terms of two contrasting storage approaches between forward (F) and reverse (R) direction. The samples for the F method were prepared at the same time and analyzed sequentially through time. In contrast, those of reverse (R) method were prepared sequentially in advance and analyzed all at once upon the preparation of the last sample. In addition, relative performance between two different bag materials (PVF and PEA) was also assessed by using 100 ppb standard. The response factors (RF) of gaseous RSC samples were determined by gas chromatography/pulsed flame photometric detector (GC/PFPD) combined with air server (AS)/thermal desorber (TD) system at storage intervals of 0, 1, and 3 days. There is no statistical difference in all RSCs between two storage methods. However, the results of relative recovery indicated 2.58~12.8% differences in compound type between the two storage methods. Moreover, loss rates and storage stability of $H_2S$ and $SO_2$ were considerably affected by bag materials than any other variables. Therefore, some considerations about storage methods (or bag material types) for sulfur compounds are needed if stored by sampling bag method.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.5
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• pp.429-434
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• 2005

In this paper, the maze navigation system using image recognition for autonomous mobile robot is proposed. The proposed maze navigation system searches the target by image recognition method based on ADALINE neural network. The infrared sensor system must travel all blocks to find target because it can recognize only one block information each time. But the proposed maze navigation system can reduce the number of traveling blocks because of the ability of sensing several blocks at once. Especially, due to the simplicity of the algorithm, the proposed method could be easily implemented to the system which has low capacity processor.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.1
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• pp.17-24
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• 2018

Polar fomat algorithm (PFA) was derived from medical imaging theory, known as back projection, to process synthetic aperture radar(SAR) data. The difference between the operating condition of SAR and back projection assumption makes two distortions. First, the focusing performance of PFA is degraded in proportion to distances from the scene center. Second, the geometric accuracy in SAR images is distorted. Several methods were introduced to mitigate the distortions, but some disadvantages, such as the geometric discontinuity, are arisen when sub-images are combined. This paper proposes the novel method to compensate the geometric distortion with chirp Z-transform (CZT). This method corrects precisely the geometric errors without any problems, because a whole image can be processed all at once.

• The KSFM Journal of Fluid Machinery
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• v.19 no.2
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• pp.27-35
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• 2016

The purpose of this study is to develop a method to predict the performance and economics of a micro gas turbine cogeneration system using performance correction curves. The variables of correction curves are ambient temperature, ambient pressure, relative humidity and load fraction. All of the values of correction factors were expressed as relative values with respect to design values at the ISO conditions. Once the correction curves are obtained, system performance can be predicted relatively easily compared to a detailed performance analysis method through a simple multiplication of the correction factors of various variables at any operating conditions. The predicted results using the correction curve method were compared with those by the detailed and more complex performance analysis in a wide operating range, and its feasibility was confirmed. To illustrate the usability of the correction curve method, the results of an economic analysis of a cogeneration system considering varying operating ambient condition and load was presented.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1280-1285
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• 2004

ADC railway system has low feeder voltage, The fault current can be smaller than the current of load starting. So it is important to discriminate between the small fault current and the load starting current. The load starting current increases step by step but the fault current increases all at once. As for the load starting current, the time constant of load current at each step is much smaller than that of the fault current. First, to detect faults in DC railway systems, an algorithm using the time constant calculated by the method of least squares is presented in this paper.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.91-94
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• 2003

A DC railway system has low feeder voltage, The fault current can be smaller than the current of load starting. So it is important to discriminate between the small fault current and the load starting current. The load starting current increases step by step but the fault current increases all at once. So the type of ${\Delta}I$ relay(50F) was developed using the different characteristics between the load starting current and the fault current. As for the load starting current, the time constant of load current at each step is much smaller than that of the fault current. First, to detect faults in DC railway systems, an algorithm using the time constant calculated by the method of least squares is presented in this paper. Secondly, to compose a protection scheme for DC railway systems is presented in this paper.

• Proceedings of the KIEE Conference
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• 2004.11b
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• pp.14-16
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• 2004

A DC railway system has low feeder voltage, The remote fault current can be smaller than the current of load starting. So it is important to discriminate between the small fault current and the load starting current. The load starting current increases step by step but the fault current increases all at once. As for the load starting current, the time constant of load current at each step is much smaller than that of the fault current. To detect faults in DC railway systems, an algorithm using the time constant calculated by the method of least squares was presented. But, It have a weakness about harmonic to calculate time constant. So in this paper, new protection algorithm for DC railway systems using estimation of time constant based on fourier transform was presented.

• Proceedings of the KIEE Conference
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• summer
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• pp.307-309
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• 2004

A DC railway system has low feeder voltage, The remote fault current can be smaller than the current of load starting. So it is important to discriminate between the small fault current and the train starting current. The train starting current increases step by step but the fault current increases all at once. So the type of $\bigtriangleup I\;relay(50F)$ was developed using the different characteristics between the load starting current and the fault current. As for the train starting current, the time constant of train current at each step is much smaller than that of the fault current. To detect faults in U railway systems, an algorithm that is independent of train starting current. This algorithm use the time constant calculated by the method of least squares is presented in this paper.