• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.4
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• pp.60-74
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• 2007

For quantitative analysis of spatio-temporal distribution pattern on marine environment, spatial autocorrelation statistics on the both global and local aspects was applied to the observed data obtained from Gwangyang Bay in South Sea of Korea. Global indexes such as Moran's I and General G were used for understanding environmental distribution pattern in the whole study area. LISAs (local indicators of spatial association) such as Moran's I ($I_i$) and $G_i{^*}$ were considered to find similarity between a target feature and its neighborhood features and to detect hot spot and/or cold spot. Additionally, the significance test on clustered patterns by Z-scores was carried out. Statistical results showed variations of spatial patterns quantitatively in the whole year. Then all of general water quality, nutrients, chlorophyll-a and phytoplankton had strong clustered pattern in summer. When global indexes showed strong clustered pattern, the front region with a negative $I_i$ which means a strong spatial variation was observed. Also, when global indexes showed random pattern, hot spot and/or cold spot were/was found in the small local region with a local index $G_i{^*}$. Therefore, global indexes were useful for observing the strength and time series variations of clustered patterns in the whole study area, and local indexes were useful for tracing the location of hot spot and/or cold spot. Quantification of both spatial distribution pattern and clustering characteristics may play an important role to understand marine environment in depth and to find the reasons for spatial pattern.

• Journal of the Korean Society for Marine Environment & Energy
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• v.14 no.2
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• pp.93-106
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• 2011

This review has dealt with definition, size, history, and status of mesocosm, and also discussed several problems and trouble shootings related to the building of mesocosm, and finally will suggest the future directions of this scientific tool. Due to the restriction of the space, the discussion mainly focused on "the mesocosm building for the soft-bottom ecosystem". The mesocosm is defined as "medium-sized, self-sustaining, and man-controllable ecosystem". This type of studies has already initiated since 1960, but nowadays it expands to the diverse fields of science and technologies, such as toxicology, limnology, environmental sciences and engineering, and even geochemistry. As a scientific tool, the mesocosm requires following aspects; replicability, repeatability, and ecological realism or accuracy. Several technical problems have to be solved for the perfect building of mesocosm. They are known as scaling, composition of seawater/sediment, light intensity, turbulence, hydraulic residence time, and top predator. These trouble shootings are provided at the discussion in detail. In the context, I expect two promising directions in the future; 1. Objectivity based on the diverse statistical methodologies, 2. "Living ecosystem modelling" coordinated with the mathematical modelling. With these, the mesocosm will be more powerful tool for the scientists and engineers to investigate the chemical and the ecological responses to the toxic materials and global climate changes.

• Korean Journal of Poultry Science
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• v.9 no.1
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• pp.1-16
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• 1982

Excessive fat deposition, particularly in the abdominal region, has become a problem in broiler production. When the caloric intake exceeds the body demands for energy, excess food is stored as fat in broilers. Researchers have shown that fat deposition varies with breed, strain, sex age, nutrition, exercise, ambient temperature and rearing systems. These factors affect fat deposition through their effects on the size or the number of adipose cells or a combination of both. In some measurements on live birds to predict body fat, the wet weight and percentage fat of skin in pectoral feather tract are significantly correlated with percentage abdominal fat. But these correlation coefficients are not so high. Therefore, correlation coefficients indicate that these measurements on live birds ate not useful for estimating body fat weight and percentage. Most reports show that an increase in the proportion of carcass fat, when measured at a given age, is correlated with selection for increased body weight. On the other hand some research results show that selection for body$.$weight gain dose not lead to an alteration in the proportion carcass fat when measured at a given body weight. Besides, selection for improved food conversion efficiency alone resulted in a decrease in carcass fat and an increase in protein and water when measured at either a given age or body weight, Thus eventhough it is uncertain whether carcass fat is increasing as a result of body-weight selection in broilers: however it is clear that selection for improved food conversion efficiency, either alone or in combination with growth rate, should result in leaner carcasses than selection for growth rate alone.

• Journal of Life Science
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• v.23 no.8
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• pp.1064-1072
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• 2013

Circadian rhythm is controlled by hormonal oscillations governing the physiology of all living organisms. In mammals, the main function of the pineal gland is to transform the circadian rhythm generated in the hypothalamic suprachiasmatic nucleus into rhythmic signals of circulating melatonin characterized by a largely nocturnal increase that closely reflects the duration of night time. The pineal gland has lost direct photosensitivity, but responds to light via multi-synaptic pathways that include a subset of retinal ganglion cells. Rhythmic control is achieved through a tight coupling between environmental lighting and arylalkylamine-N-acetyltransferase (AANAT) expression, which is the rhythm-controlling enzyme in melatonin synthesis. Previous studies on the nocturnal expression of AANAT protein have described transcriptional, post-transcriptional, and post-translational regulatory mechanisms. Molecular mechanisms for dependent AANAT expression provide novel aspects for melatonin's circadian rhythmicity. Extensive animal research has linked pineal melatonin for the expression of seasonal rhythmicity in many mammalian species to the modulation of circadian rhythms and to sleep regulation. It has value in treating various circadian rhythm disorders, such as jet lag or shift-work sleep disorders. Melatonin, also, in a broad range of effects with a significant regulation influences many of the body's physiological functions. In addition, this hormone is known to influence reproductive, cardiovascular, and immunological regulation as well as psychiatric disorders.

• Journal of the Korean Society for Library and Information Science
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• v.33 no.1
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• pp.67-86
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• 1999

It needs to be considered that citing is net a static process but a dynamic process which is to produce to reproduce and to distribute knowledge by the interaction between societies surrounding the citer. This study begins by briefly acknowledging that citation is a universal practice in terms of establishing citer's own basis of research on the basis of the relation to previous studies and persuadeing potential citer to cite his/her research product. This study, however, is a preliminary attempt to examine the premise that although citing is a unversal practice. but citer motivations can be influenced by various citation environmental contexts surrounding the citer. This study presented general citation motivations derived from previous studies: (1) substantial motivations - conceptional and methodological citations 2) persuasive motivations - positive, applied, and negative citations, (3) perfunctory motivations - perfunctory and bibliographic citations, and (4) social relation motivations - personal connections and knowledge familiarity citations. In addition, this study identified citation environment factors affecting these citation motivations: (1) citer and documentation factor, (2) social and cultural environment, (3) information environment, and (4) international knowledge system environment. Each citation environment factor presented should be interpreted not as a separate factor, but rather as a close interrelation among these environment factors, Finally, the model of the citation environment factors developed in this study was discussed in the aspects of the relationship between citation motivations and their citation environment factors. This study suggested that further research should be conducted in order to examine these relationships more empirically and citation should be considered as a social product reflecting the interaction between citer and various citation environments.

• Journal of radiological science and technology
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• v.27 no.4
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• pp.75-83
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• 2004

The objective of this study is to find out the factors affecting the satisfaction of the students at the department of radiotechnology of health college for their clinical practice and provide the basic data necessary for the better planning of the curriculum for the clinical practice. The questions were distributed to and collected from 227 junior college students in Seoul and Kyeonggido from January to february, 2004. All statistical analyses were carried out using SPSS/PC+. The general characteristics of students and the current clinical practice conditions were presented in real numbers and percentages. The responding scores for the degree of satisfaction vary from 1 to 5, where is the worst score and 5 the best. The degree of satisfaction for clinical practice was presented as the average score and the standard deviation for each item shown. 1.The degree of satisfaction for the clinical practice was assessed in total eight aspects. and the overall average score was $3.64^{\circ}$. The degree of satisfaction for practice period was scored 3.69, which was higher than the average. Environmental aspect was scored 3.57, suggesting relatively low satisfaction. The degree of satisfaction for parts, evaluation method of clinical practice, education, practice contents, achievement after clinical practice, and personal relationship in practice were presented 3.64, 3.21, 3.37, 4.00, 3.88, and 3.72 respectively. The degree of evaluation method of clinical practice was the lowest among them. 2. The students favored the clinical practice course offered in the second semester of their third year and a total of 8 weeks for the period. 3. The major complaints of the students during the clinical practice were simple works, insufficient rest place and conflict with practice teachers. As mentioned above, the degree of satisfaction for the achievement after clinical practice and item necessary for clinical practice showed relatively high scores. It turns out that the students think of their clinical practice as very positive in answering the questionnaire.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.2
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• pp.184-193
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• 2015

Objectives: This study focused on three aspects: characterizing concentrations of airborne particles by size distributions and asbestos fibers generated by various building materials; analyzing the characteristics of fibers produced by each simulation and asbestos fibers released from ACBMs; and investigating correlations of airborne asbestos fibers and particles generated and association of particle and asbestos concentrations. Methods: We selected three ACBMs including an insulation board, cement asbestos slate and wallboard. We constructed 4 scenarios; a) crushing with a hammer; b) cutting with a industrial knife; c) brushing with a metal brush; and d) tightening & loosening with a hand drill. We implemented one simulation for 30 seconds followed by 30 seconds resting period. We repeated a total of 5 cycles for 5 minutes. Results: The highest concentration of particulate & fibrous matters was from crushing with a hammer in each scenario followed by brushing with a metal brush, cutting with a industrial knife, and tightening & loosening with a hand drill. For ACBMs studied, asbestos concentrations were highest from an insulation board followed by cement asbestos slate, and wallboard. No difference in terms of concentration was found between an insulation board and asbestos slate. Fibers with $5{\sim}20{\mu}m$ in length were included in 76~90% of total fibrous matters. The distribution of the straight form fibers was greater than that of the curl form. About 90% of $PM_{Total}$ released from ACBMs was consisted of $PM_{10}$ while only 10% of $PM_{Total}$ was $PM_{2.5}$. Particulate matters like $PM_{2.5}$ was significantly correlated with fibrous matters($R^2=0.81$). Conclusions: We found ACBMs can significantly release asbestos fibers as well as $PM_{2.5}$. Concentrations of asbestos generated by ACBMs were well correlated with $PM_{2.5}$.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.517-524
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• 2004

The objective of this study was to investigate the environmental effects on duration time of milk flow, peak milk flow, and average milk flow in teats, and to estimate their relationships with milk yields in morning and evening milking, and to provide fimdamental information for the further study on their relationships with clinical mastitis and somatic cell in milk. A total of 6,768 milking records were studied in 72 Holstein cows. The influences of season, parity, lactation month, and milking interval on characteristics of milk flow considering in linear model were significant(p<.05). Duration of milk flow was longest at milking in fall, past first parity and second month of lactation, and with milking interval over than 13.5hrs. Average milk flow rate and peak milk flow rate were highest at milking in summer, past first parity and 8${\sim}$10 months of lactation, and with milking interval over than 13.5hrs. Milk flow rate was positively correlated to milk yield, and negatively correlated to the duration of milk flow. However duration milk flow was positively correlated to the milk yield with high level of correlation coefficient(+.60). For the establishment of optimum selection criteria on these traits, other aspects such as the udder health, disease and respective economic weights of milk flow characteristics in this study must be considered to develop the indices.

• Environmental and Resource Economics Review
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• v.19 no.4
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• pp.853-874
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• 2010

This study examines the acceptability of nuclear facilities using the latent class analysis. Even though, nuclear power is useful in terms of economic and energy security aspects, it is very difficult to expand the existing nuclear power plants or build a new one. Many studies analysed the cause of unacceptability of nuclear facilities but it has not been focused how large portion of people are divided pro and con. It is very important to know the distribution of people by the attitude toward nuclear facilities in order to meet the long term National Energy Plan. Through the latent class analysis with 1,025 respondents, people are classified into three groups(favor-class, support-class, opposition-class). The favor-class is the largest group which has moderate good attitudes toward the nuclear facilities in terms of economy, cleanness. and necessity but concerns a little about safety. The second largest group is the support-class which comprises 1/4 portion of people. The people in the class show the aggressive support for the nuclear facilities. 15% of the respondents belong to the opposition-class which show the negative attitudes to expansion of neclear facilities. In order to increase the acceptability of nuclear faculties, the most urgent work for the government to do is to less people's concern about nuclear safety.

• Journal of Energy Engineering
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• v.24 no.4
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• pp.89-96
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• 2015

Recently, much research has been put into finding the causes and solutions of slagging/fouling problems that occur at the end of the boiler. This slagging/fouling, caused by low-rank coal's ash, disturbs the thermal power and greatly reduces efficiency. In environmental aspects, such as NOx pollution, governments have been implementing restrictions on the quantity of emission gases that can be released into the atmosphere. To solve these problems, research on Ash Free Coal (AFC), which eliminates ash from low-rank coal, is in progress. AFC has advantages over similar high-rank coals because it increases the heating value of the low grade coal, reduces the contaminants that are emitted, and decreases slagging/fouling problems. In this study, using a DTF, the changes of NOx emissions, unburned carbon, and the characteristics of ash deposition were identified. KCH raw coal, AFC extracted from KCH, residue coal, Glencore, and Mixed Coal (Glencore 85wt% and residue coal 15wt%) were studied. Results showed that AFC had a significantly lower emission of NOx compared to that of the raw coal and residue coal. Also, the residue coal showed a higher reactivity compared to raw coal. And finally, In the case of the residue coal and mixed coal, they showed a lower ash deposition than that of low-rank coal.