• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.27 no.1
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• pp.13-20
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• 1991

This paper describes the fish-density dependence of the mean backscattering strength with aggregations of encaged, free-swimming fish of known density in relation to the experimental verification of echo-integration technique for estimating the density of fish shoals. In this experiment, various numbers of gold crussian, Carassius burgeri burgeri, with a mean length of 18.5cm and a mean weight of 205.9g, were introduced into a net cage of approximately 0.76m super(3). During the backscattering measurements. the cage was suspended on the sound axis of the 50kHz transducer having a beam width of 33 degrees at -3dB downpoints. The volume backscattering strengths from fish aggregations were measured as a function of fish density. Data acquisition, processing and analysis were performed by means of the microcomputer-based sonar-echo processor including a FFT analyzer. The calibration of echo-sounder system was carried out at field with a steel ball bearing of 38mm in diameter having the target strength of -40.8dB. The dorsal-aspect target strengths on anesthetized specimens of gold crussian used in the cage experiment were measured and compared with the target strength predicted by the fish density-echo energy relationship for aggregations of free-swimming gold crussian in the cage. The results obtained can be summarized as follows: 1. The target strengths in the dorsal aspect on anesthetized specimens of gold crussian, with the mean length of 19.1cm and the mean weight of 210.5g, varied from -40.9dB to -44.8dB with a mean of -42.6dB. This mean target strength did not differ significantly from that predicted by the regression of echo energy on fish density of free-swimming gold crussian in the cage. It suggests that the target-strength measurements on anesthetized fish was valid and can be representative for live, free-swimming fish. 2. The relationship between mean backscattering strength(, dB) and distribution density of gold $crussian(\rho, $ fish/m super(3)) was expressed by the following equation; =-41.9+11 $Log(\rho)$ with a correlation coefficient of 0.97. This result support the existence of a linear relationship between fish density and echo energy, but suggest that this line has steeper slope than the regression by the theory of estimating the density of fish schools.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.4
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• pp.1690-1698
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• 2012

As alcohol use is one of the most important risk factors for injuries, this study was intended to clarify and evaluate any relationship between drinking patterns and the incidence rates/specific characteristics of injuries in adult populations, using a widely accepted tool, the Alcohol Use Disorders Identification Test (chronic alcohol drinking behaviors measurement, hereinafter the AUDIT) developed by the World Health Organization to help to assess the behaviors in a more accurate and reliable manner. This study used the data collected from the 2009 Korea National Health and Nutrition Examination Survey (KNHANES), in which 7,511 of 7,893 adult participants aged ${\geq}19$ years answered the questions about injuries, and excluding 104 non-respondents, 6,258 of participants in the questionnaire survey of drinking patterns were finally analyzed. The incidence rates and specific characteristics of injuries as classified by the AUDIT categories (i.e., body regions, types and mechanisms) were assessed and estimated in terms of their relative risk using t-test, ANOVA, and logistic regression. SPSS 19.0 statistical package software was employed for statistical analyses. These analyses indicate that the incidence rates of overall injuries were significantly higher in male respondents than in female respondents. The risks of alcohol use related injuries were 8.3 times higher in male respondents than in female ones. Regarding educational background, high school graduates showed the highest rates in the AUDIT with significant difference from the other groups. The married group and the group of respondents having monthly income estimated at KRW 2.01 to 3 million also showed the highest rates in the AUDIT compared to the other groups, indicating statistically significant difference. Significantly increased in problematic drinkers and those with alcohol dependence, the incidence rate of injuries body regions was 0.0371 in the head/neck, and with respect to the AUDIT and the mechanisms of external causes of injuries, transport accidents ranked first, followed by slippage, others, crash and fall. In regard to the classified types of injuries, it was statistically significant in others (e.g., laceration, contusion, addiction, or penetrating wound). In conclusion, the mechanisms of external causes of injuries as well as injuries attributed to alcohol use are very important, and a strategy is required to reduce such the injuries in the manner of decreasing the frequency of drinking after motivation by professional counsellors.

• Korea journal of population studies
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• v.25 no.2
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• pp.5-40
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• 2002

Using detailed data of women's work history, this study analyses the transition process between employment and non-employment over the life history in order to identity individual and structural determinants in the processes. Korean women comprise very heterogeneous groups in terms of work continuity: one group having a continuous work history and another having an interrupted work experience. While 4.0% of total women have stayed in the labor market since leaving school, 17.3% have not worked outside at all and remaining 87.9% have experienced into and out of the labor market at least once. On the average, the cumulated time of employment per woman is 8.2 years and the cumulated time of unemployment is 13.1 years. Thus Korean women work a total of only 38.5% of their whole lifetime after leaving school. We can conclude that the increase of the employment rate of married women in Korea since the 1970s has been due to the increase of the new entrants with short or little working careers into the labor market, not to the increase of women's work continuity on the whole. A women's educational achievement does not seem to be positively related to employment duration, contrary to the suggestion of the human capital theory, Rather, family variables, especially the existence of the child under 6 yens old, is a more significant determining factor for an individual's exit from employment. And there is little difference among different age cohorts which implies little improvement in the employment continuity of younger women. This study also documents the importance of structural variables, such as the type of occupation, as significant determining factors for the hazard rate. Specially women with professional jobs tend to stay longer in the labor market. Therefore, women's entry into more professional occupations is expected to contribute to the continuity of employment. Our results also show that duration-dependence is not spurious. When unobserved heterogeneity is controlled, the negative relation between the rate from employment and the duration of employment does not disappear.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.3
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• pp.189-198
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• 2000

The stochiometric mixture of evaporating materials for the $CuGaSe_2$single crystal thin films were prepared from horizontal furnace. Using extrapolation method of X-ray diffraction patterns for the polycrystal $CuGaSe_2$, it was found tetragonal structure whose lattice constant $a_0}$ and $c_0$ were 5.615 $\AA$ and 11.025 $\AA$, respectively. To obtains the single crystal thin films, $CuGaSe_2$mixed crystal was deposited on throughly etched GaAs(100) by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were $610^{\circ}C$ and $450^{\circ}C$ respectively, and the growth rate of the single crystal thin films was about 0.5$\mu\textrm{m}$/h. The crystalline structure of single crystal thin films was investigated by the double crystal X-ray diffraction (DCXD). Hall effect on this sample was measured by the method of van der Pauw and studied on carrier density and mobility depending on temperature. From Hall data, the mobility was likely to be decreased by pizoelectric scattering in the temperature range 30 K to 150 K and by polar optical scattering in the temperature range 150 K to 293 K. The optical energy gaps were found to be 1.68 eV for CuGaSe$_2$sing1e crystal thin films at room temperature. The temperature dependence of the photocurrent peak energy is well explained by the Varshni equation then the constants in the Varshni equation are given by $\alpha$ = $9.615{\times}10^{-4}$eV/K, and $\beta$ = 335 K. From the photocurrent spectra by illumination of polarized light of the $CuGaSe_2$single crystal thin films. We have found that values of spin orbit coupling $\Delta$So and crystal field splitting $\Delta$Cr was 0.0900 eV and 0.2498 eV, respectively. From the PL spectra at 20 K, the peaks corresponding to free bound excitons and D-A pair and a broad emission band due to SA is identified. The binding energy of the free excitons are determined to be 0.0626 eV and the dissipation energy of the acceptor-bound exciton and donor-bound exciton to be 0.0352 eV, 0.0932 eV, respectively.

• The Journal of Small Business Innovation
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• v.19 no.4
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• pp.1-17
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• 2016

The purpose of this study is to suggest an efficient way for ventures to achieve innovation performance through R&D cooperative arrangements. Achieving innovation is one of the critical factors for the survival of ventures. Unlike established firms, ventures often do not have the specialized assets necessary to take technological developments to the product and market stages. Young and resource-constrained firms can achieve innovation by finding and accessing to the complementary resources from R&D cooperation. In the current business environment, many firms are likely to engage in multiple simultaneous R&D cooperations with different partners. Recent research stream addresses the importance of efficient cooperation management from the holistic portfolio perspective. Since maintaining the multiple cooperative relations require substantial amount of time and effort, managing cooperative relationships play a more important role to resource-constrained firms. In order to find an efficient composition of R&D cooperative partners, we mainly focus on the diversity of partner type and dependence level in partnership. We analyze the data on Korean manufacturing ventures collected in the Korean Innovation Survey (KIS) which was conducted by the Science and Technology Policy Institute (STEPI). The KIS questionnaire assesses the existence of cooperative relationships with different types of partners respectively. The types of cooperating partners are affiliated companies, suppliers, clients & customers, competitors or other firms in the same industry, consulting firms, universities, and research institutes. We confirm that ventures obtain relatively higher benefits from R&D cooperation compared with established firms in terms of innovation performance. The results show that a moderate level of diversity in cooperative partner type composition increases innovation. Moreover, diversity of cooperation dependency among the partners enhances innovation performance. Likewise, concentrating on the quality aspects of cooperative composition, such as diversity of partners and degree of dependencies, this study offers some implications for ventures in managing partners from an integrative perspective.

• Journal of Preventive Medicine and Public Health
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• v.36 no.2
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• pp.137-146
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• 2003

Objectives : Impaired hearing is a prevalent occupational hazard, not only in industry, but also in the armed forces. In military life, noise has unusual characteristics, and constitutes a serious hazard to hearing. The aim of this study was to analyze the hearing threshold data in order to compare the hearing loss among shipyard workers, representing different workers, and a military service background. Methods : A cross-sectional audiological survey, combined with a questionnaire study, was conducted on a stratified random sample of 440 shipyard workers, with long-term exposure to noise. The employees were divided into four groups, according to their working and military service backgrounds, in relation to their exposure to noise. Results : As expected, the working and military noise exposure group (Group I) had significantly poorer hearing than the other groups. The high frequencies (2-8 kHz) showed the greatest difference in terms of poorer fearing in both ears. The prevalence of noise-induced hearing loss (NIHL) was highest in Group I. A logistic regression analysis was applied to determine the dependence of the NIHL in relation to age, smoking, drinking, working duration, ear protection, past history of ear diseases, and working and military sonics backgrounds, on the noise exposure The important factors found to be related to the NIHL, in relation to noise exposure were: age, work duration, and working and military service backgrounds. The adjusted odds ratio estimates for NIML in the right ear were 4.5 times greater (95% CI 1.7-11.6) for the military noise exposed group, and 7.9 times greater (95% CI 2.0-31.3) for the working noise exposed group than in the controls. The hearing thresholds at the pure-tone average and 4 kHz were significantly increased with age and work duration with both the working and military service backgrounds. Conclusions : From these results, specific preventive programs were planned, which should be assessed by epidemiological surveillance of the military noise exposed population.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.4
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• pp.280-290
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• 2007

Purpose: Gender differences in personality are considered to have biological bases. In an attempt to understand the gender differences of personality on neurobiological bases, we conducted correlation analyses between regional brain glucose metabolism and temperament factors of personality in males and females. Materials and Methods: Thirty-six healthy right-handed volunteers (18 males, 33.8$\pm$17.6 y; 18 females, 36.2$\pm$20.4 y) underwent FDG PET at resting state. Three temperament factors of personality (novelty seeking (NS), harm avoidance (HA), reward dependence (RD)) were assessed using Cloninger's 240-item Temperament and Character Inventory (TCD within 10 days of FOG PET scan. Correlation between regional glucose metabolism and each temperament factor was tested using SPM2. Results: In males, a significant negative correlation between NS score and glucose metabolism was observed in the bilateral superior temporal gyri, the hippocampus and the insula, while it was found in the bilateral middle frontal gyri, the right superior temporal gyrus and the left cingulate cortex and the putamen in females. A positive HA correlation was found in the right midbrain and the left cingulate gyrus in males, but in the bilateral basal ganglia in females. A negative RD correlation was observed in the right middle frontal and the left middle temporal gyri in males, while the correlation was found in the bilateral middle frontal gyri and the right basal ganglia and the superior temporal gyrus in females. Conclusion: These data demonstrate different cortical and subcortical metabolic correlates of temperament factors of personality between males and females. These results may help understand biological substrate of gender differences in personality and susceptibility to neuropsychiatric illnesses.

• Economic and Environmental Geology
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• v.46 no.6
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• pp.521-533
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• 2013

This study was initiated to evaluate the applicability of Si slag as an adsorbent via investigation of the main properties of Si slag as an adsorbent aw well as characterization of adsorption features between aqueous arsenic and Si slag. The specific surface area of Si slag was measured to be 6.71 $m^2/g$ which seems to be slightly higher than those of other slags, but relatively lower than those of iron (oxyhydr)oxides extensively used for arsenic controlling processes. The point of zero salt effect (PZSE) of Si slag determined by potentiometric titration appeared to be comparatively high (7.3), indicating the Si slag may be favorably used for adsorption of arsenic which predominantly exists as an oxy-anions. The results of adsorption isotherm indicate that regardless of arsenic species, Langmuir-type isotherm is the most suitable to simulate the adsorption of arsenic onto Si slag. With regard to pH-dependence of arsenic adsorption, the adsorption maxima of arsenite was centered at pH 7, and the adsorption was remarkably decreased in the other pH conditions. In the case of arsenate, on the other hand, the adsorption was highest at the lowest pH (4.0) and then gradually decreased with the increase of pH. Based on the results of kinetic experiments, it is likely that the adsorption of arsenite approached equilibrium within 2 hr, but it took about 8 hr for arsenate adsorption to be equilibrated. In addition, the Pseudo second order was evaluated to be most consistent with the empirical data of arsenic adsorption onto Si slag in this study. Under identical conditions, the affinity of arsenate onto Si slag was estimated to be nearly 6 times higher than that of arsenite.

• Radiation Oncology Journal
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• v.18 no.4
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• pp.277-282
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• 2000

Purpose : Though It has been known that the to tolerance of the liver to external beam irradiation depends on the irradiated volume and dose, few data exist which Quantify this dependence. However, recently, with the development of three dimensional (3-D) treatment planning, have the tools to Quantify the relationships between dose, volume, and normal tissue complications become available. The objective of this study is to investigate the relationships between normal tissue complication probabili쇼 (WCP) and the risk of radiation hepatitis for patients who received variant dose partial liver irradiation. Materials and Methods : From March 1992 to December 1994, 10 patients with hepatoma and 10 patients with bile duct cancer were included in this study. Eighteen patients had normal hepatic function, but 2 patients (prothrombin time 73$\%$, 68$\%$) had mild liver cirrhosis before irradiation. Radiation therapy was delivered with 10MV linear accelerator, 180$\~$200 cGy fraction per day. The total dose ranged from 3,960 cGy to 6,000 cGy (median dose 5,040 cGy). The normal tissue complication probability was calculated by using Lyman's model. Radiation hepatitis was defined as the development of anicteric elevation of alkaline phosphatase of at least two fold and non-malignant ascites in the absence of documented progressive. Results: The calculated NTCP ranged from 0.001 to 0.840 (median 0.05). Three of the 20 patients developed radiation hepatitis. The NTCP of the patients with radiation hepatitis were 0.390, 0.528, 0.844(median : 0.58$\pm$0.23), but that of the patients without radiation hepatitis ranged fro 0.001 to 0.308 (median .0.09$\pm$0.09). When the NTCP was calculated by using the volume factor of 0.32, a radiation hepatitis was observed only in patients with the NTCP value more than 0.39. By contrast, clinical results of evolving radiation hepatitis were not well correlated with NTCP value calculated when the volume factor of 0.69 was applied. On the basis of these observations, the volume factor of 0.32 was more correlated to predict a radiation hepatitis. Conclusion : The risk of radiation hepatitis was increased above the cut-off value. Therefore the NTCP seems to be used for predicting the radiation hepatitis.

• Journal of dental hygiene science
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• v.11 no.6
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• pp.535-542
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• 2011

The purpose of this study was to examine the state of smoking among adolescents and their smoking-related oral health knowledge. The subjects in this study were the teens who were selected by convenience sampling from among the students who were in their first, second and third years in four different middle schools in the city of Iksan, North Jeolla Province. A self-administered survey was conducted from June 14 to July 12, 2011, and the answer sheets from 1,219 respondents were selected for analysis. The collected data were analyzed by the statistical package 12.0, and the findings of the study were as follows: 1. The smoker students accounted for 10.6 percent. The boys and girls who smoked respectively represented 16.0 and 5.4 percent. 2. As for the period of smoking, the largest group that accounted for 51.6 percent smoked for less than a year. Concerning the amount of daily smoking, the greatest group that accounted for 91.9 percent smoked less than 10 cigarettes. As to the motivation of smoking, the biggest group that represented 52.8 percent started to smoke out of curiosity. 3. Regarding smoking-related oral health knowledge, they got a mean of 0.85. Their scores in knowledge of oral malodor(0.95), oral cavity cancer(0.94) and periodontal diseases(0.93) were above the average, and their scores in knowledge of dental caries(0.70) and blunting of taste(0.77) were below the average. 4. The seventh graders got the best score of 5.28 in smoking-related oral health knowledge(p<0.01), and the students who were more satisfied with their life had a better oral health knowledge(p<0.05). 5. The senior students were more dependent on nicotine(p<0.01), and the number of smoking days(${\beta}=0.407$, p<0.001) and the period of smoking(${\beta}=0.235$, p<0.01) affected their nicotine dependence.