• Korean Journal of Health Education and Promotion
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• v.18 no.2
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• pp.27-44
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• 2001

In this study, I investigate the drinking behavior and related factors among white collar workers in seoul. Examination was executed with questionnaire to 520 white collar workers. Drinking behavior involves frequency of drinking, amount of alcohol consumption in a drinking situation and alcohol-related problem. Related factors involves the general characteristics, the knowledge about alcohol, the allowable attitude about drinking, work stress and stress copying. This was analyzed with percentage, mean, standard deviation, t-test, ANOV A and pearson's correlation. The results are as follows: Data shows that about 96.3% of the respondents drink at least during the last year and 89.8% of the respondents drink at least during the last month. 59.4% male respondents drink 3-8 times a month, 44.8% female respondents drink 1-2 times a month. High prevalence rates were found in male, married person and those with low-religious spirit in a usual amount of drinking(p〈0.05), male in the latest amount of drinking(p〈0.05), male, forties, married person and those with the highest monthly family income and those with low-religious spirit in frequency of drinking during the latest month(p〈0.05). The score of alcohol-related problem(ARP) was as follows: male workers-2.61, female workers-1.61 out of 35. The score of ARP was statistically significantly different according to sex(p〈0.05). A positive correlation was observed between amount of drinking, frequency of drinking and ARP(p〈0.01). The score of knowledge about alcohol was 3.6 and any correlation and statistically significant difference were not observed between the knowledge about alcohol and drinking behavior. The score of allowable attitude about drinking was statistically significantly different according to sex(p〈0.05), age(p〈0.05). A positive correlation was observed between attitude about drinking and amount of drinking, frequency of drinking, ARP(p〈0.01). The work stress and stress copying had no significant relations with drinking behavior. Most respondents do not drink at stress situation.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.5
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• pp.74-84
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• 2017

Since a soldier manages a hand-held landmine detector by hands, it is necessary to develop a system that can detect the target quickly and accurately. However, the hand-held landmine detector used in Korea has a problem that it can only detect the metal mines. Therefore, it is important to solve the problem and to develop a hand-held landmine detection system suitable for the Korean environment. In this paper, we propose a hand-held landmine detection system suitable for the Korean environment using ground penetrating radar. The proposed system uses depth compensation, matched filtering, and frequency shifting filtering for preprocessing. Then, in the detection step, the system detects the target using the edge ratio. In order to evaluate the proposed system, we buried landmines in sandy loam which is most of the soil in Korea and obtained a set of ground penetrating radar data by using a hand-held landmine detector. By using the obtained data, we carried out some experiments on the size and position of the patch and the shifting frequency to find the optimal parameter values and measured the detection performance using the optimized values. Experimental results show that the proposed preprocessing algorithms are suitable for detecting all landmines at low false alarm rate and the performance of the proposed system is superior to that of previous works.

• Journal of Oriental Neuropsychiatry
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• v.17 no.1
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• pp.17-35
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• 2006

Objects : In the present study, we translated Mingyi-leian into modern Korean, and studied the medical records about the disease induced by emotional problem and the psychotherapy in Mingyi-leian for find the possibility of application that established researches did not studied. Methods : It was 197 cases that related to psychotherapy and emotional problem called Seven Passions(七情). We studied these records by statistical methods. Results : The anger(怒) was the most numerous cause into classified to Seven Passions in 197 cases. In the order of frequency of emotional causes, it was worry(憂), surprise(驚), lust(思), fear(恐), sorrow(悲), joy(喜) that classified into Seven Passions. The most disease induced by emotional problem was internal trauma(內傷), 11 cases. There was very numerous diseases induced by emotional problem except internal trauma. In ratio of the sexes, it was 104 cases in female and 93 cases in male from 197 cases. But the number of all case records about male were more than about female in Mingyi-leian, so female ratio was two times to male ratio. Specially, the percentage of cases about disease due to anger high in female. In ratio of the Seven Passions, the anger was most frequent cause of diseases due to emotional problem in 197 cases, and mostly caused bleeder's diseases. In oral medical treatments, various prescriptions were used. On the whole, the ratio of prescriptions about venting grudges(解鬱) records are mostly application of compatibility and incompatibility with the and warmly strengthening(溫補) were high. Psychotherapeutic medical Five Elements(五行) relation. But it also has psychotherapeutic medical record made by detailed and correct analysis can equal to modern psychotherapy, it is worth refer to clinic. Conclusions : Mingyi-leian and its medical records about the disease induced by emotional problem and the psychotherapeutic records have sufficient meaning to not only modern neuropsychiatric physicians but also physicians of all medical fields to treat disease of this kind.

• Earthquakes and Structures
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• v.5 no.2
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• pp.161-205
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• 2013

We study seismically induced, anti-plane strain wave motion in a non-homogeneous geological region containing tunnels. Two different scenarios are considered: (a) The first models two tunnels in a finite geological region embedded within a laterally inhomogeneous, layered geological profile containing a seismic source. For this case, labelled as the first boundary-value problem (BVP 1), an efficient hybrid technique comprising the finite difference method (FDM) and the boundary element method (BEM) is developed and applied. Since the later method is based on the frequency-dependent fundamental solution of elastodynamics, the hybrid technique is defined in the frequency domain. Then, an inverse fast Fourier transformation (FFT) is used to recover time histories; (b) The second models a finite region with two tunnels, is embedded in a homogeneous half-plane, and is subjected to incident, time-harmonic SH-waves. This case, labelled as the second boundary-value problem (BVP 2), considers complex soil properties such as anisotropy, continuous inhomogeneity and poroelasticity. The computational approach is now the BEM alone, since solution of the surrounding half plane by the FDM is unnecessary. In sum, the hybrid FDM-BEM technique is able to quantify dependence of the signals that develop at the free surface to the following key parameters: seismic source properties and heterogeneous structure of the wave path (the FDM component) and near-surface geological deposits containing discontinuities in the form of tunnels (the BEM component). Finally, the hybrid technique is used for evaluating the seismic wave field that develops within a key geological cross-section of the Metro construction project in Thessaloniki, Greece, which includes the important Roman-era historical monument of Rotunda dating from the 3rd century A.D.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1648-1653
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• 2003

The paper studies effect of quasi-periodic or airplane flutter phenomenon on television broadcasting signal. Airplane flutter is a very important problem. It causes the receiving antenna to receive both direct signal by the Tx (Transmitter antenna) and reflected signal scattered by the airplane with phase delay. The sum of two signals results in fading, sometime collapse and distortion of picture on TV screen. We performed measurement and modeling this phenomenon on TV signal when the airplane flew across and range Tx and Rx (Receiver antenna). The frequency 60.75MHz (Aural frequency of CH3) is used under tests. A single scatter multipath model is introduced. It is used to duplicate some of the measured data and show the dependence of power variation on the airplane fluttering. The fluctuation of the airplane flutter phenomenon was calculated to be around 2-4dB. The Yaki antenna is used for improving airplane flutter problem because it can make high gain and high directivity.

• Journal of the Korean Chemical Society
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• v.64 no.1
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• pp.30-37
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• 2020

The purpose of this study was to identify the problems faced by students in sub-microscopic representation of acid-base reactions. Herein, we selected 30 students of 12^th grade science classes, who had studied various acid-base models. In order to investigate the sub-microscopic representation ability of the students, we developed nine items related to various contexts, such as one type of solute and solvent, two types of solutes and solvent, cases with water as solvent or with nonaqueous solvents. For all items, we consistently observed lack of concept of chemical change. In context of aqueous and nonaqueous solutions, the frequency of lack of concept of chemical bonding was high if ammonia was the solute or solvent. Moreover, the frequency of lack of concept related to the degree of electrolytic dissociation was high. Therefore, chemistry teachers should understand that students' ability to sub-microscopic representation of acid-base reactions can be enhanced by analyzing the difficulties faced by the students in solving diverse acid-base problems.

• Journal of Korean Academy of Nursing
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• v.32 no.1
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• pp.28-39
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• 2002

The purpose of this study was to measure the prevalence of urinary incontinence (UI), urologic symptoms, chronic health problems they have, and to explore whether the differences in incidence of UI ware by age, sex, voiding pattern, and chronic health problems. Method: 298 subject were selected, age range from 60 to 94 years residing in one city, in republic of Korea. Data was collected presence of UI, urologic symptoms, chronic health problems, knowledge, and the discomfort with incontinent. Collected data was analyzed with frequency, percentage, t-test, and $\chi$2-test. Result: The results of this study are as follows: 1. Mean age was 71.4 years. Prevalent rate of UI was 17.0%, woman showed more than man. 2. UI incidence was significant in age (t=7.84, p=.000), sex ($\chi$2 =9.47, p=.002), and voiding frequency ($\chi$2=18.34, p=.000). Also, UI incidence was significant relationship with chronic health problem of heart disease ($\chi$2 =10.65, p=0.001), hypertension ($\chi$2=4.04, p= 0.046) and respiratory problem ($\chi$2=9.67, p=0.002). 3. The UI was grouped into urgent incontinence (45%), stress incontinence (33%), and combined (22%). UI occurred during the daytime 48% and 17% at night. 4. Only 9.8 % of the UI seek advice and/or treatment for their symptoms, almost 90 % remained untreated due to lack of knowledge or improper information. 5. The discomforts due to their UI was no significant difference in their condition, the urgent use of the rest room, leaking urine, and nocturia. Conclusion: This study suggests that 1 year and 3 year follow-up study is needed to compare health status of UI. Also suggests intervention study for urologic discomfort of incontinent and behavioral education for the elderly are needed.

• Journal of Korean Society of Transportation
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• v.27 no.3
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• pp.91-102
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• 2009

A traffic accident prediction model developed using various design variables(road design variables, geometric variables, and traffic environmental variables) is one of the most important factors to safety design evaluation system for roads. However, statistical accident models have a crucial problem not applicable for all intersections. To make up this problem, this study developed AMFs(Accident Modification Factors) through statistical modeling methods, historical accident databases, judgment from traffic experts, and literature review by considering design variable's characteristics, traffic accident rates, and traffic accident frequency. AMFs developed in this study include exclusive left-turn lane, exclusive right-turn lane, sight distance, and intersection angle. Predictabilities of the developed AMFs and the existing accident prediction models are compared with real accident historical data. The results showed that performances of the developed AMFs are superior to the existing statistical accident prediction models. These findings show that AMFs should be considered as a important process to develop safety design evaluation algorithms. Additionally, AMFs could be used as an index that can judge the impact of corresponding design variables on accidents in rural intersections.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.6
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• pp.1333-1340
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• 2015

IEEE 802.11 MAC(Media Access Control) defines DCF(Distributed Coordination Function) for data transmission control. BEB(Binary Exponential Backoff) algorithm of DCF has a problem that if the number of stations connected are over a certain threshold, it degrades network performance because of packet collisions caused from the minimum contention window size. To cope with this problem, we proposed a novel algorithm, named as VBS(Variable Backoff Stage) algorithm, which adjusts the rate of backoff stage increment depending on the number of stations associated with an AP(Access Point). Analytic model of proposed algorithm was derived and simulations on the BEB and the VBS algorithms have been conducted on the OFDM (Orthogonal Frequency Division Multiplexing) method. Simulation results showed that when the rate of backoff state increment was 5 and 10, the number of retransmission were reduced to 1/5 and 1/10 comparing to that of BEB, respectively. Our algorithm showed improvement of 19% and 18% in network utilization, respectively. Packet delay was reduced into 1/12.

• Journal of Electrical Engineering and Technology
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• v.12 no.4
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• pp.1442-1448
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• 2017

Recently, electric power systems have been operating with tight margins and have reached their operational limits. Many researchers consider a microgrid as one of the best solutions to relieve that problem. The microgrid is generally powered by renewable energies that are connected through power converters. In contrast to the rotational machines in the conventional power plants, the converters do not have physical rotors, and therefore they do not have rotational inertia. Consequently, a stand-alone microgrid has no inertia when it is powered by the only converter-based-generators (CBGs). As a result, the relationship between power and frequency is not valid, and the grid frequency cannot represent the power balance between the generator and load. In this paper, a superconducting flywheel energy storage system (SFESS) is applied to an inertia-free stand-alone (IFSA) microgrid. The SFESS accelerates or decelerates its rotational speed by storing or releasing power, respectively, based on its rotational inertia. Then, power in the IFSA microgrid can be balanced by measuring the rotor speed in the SFESS. This method does not have an error accumulation problem, which must be considered for the state of charge (SOC) estimation in the battery energy storage system (BESS). The performance of the proposed method is verified by an electromagnetic transient (EMT) simulation.