• Environmental and Resource Economics Review
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• 제28권2호
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• pp.277-306
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• 2019

Mackerel is one of the most widely consumed aquatic products in Korea. Concerns about the depletion of stocks have also arisen as the catch has decreased. The primary purpose of this study is to estimate the mackerel stock and derive the optimal level of catch in Korea. We apply a generalized maximum entropy econometric method to estimate the mackerel growth function, which does not require the steady state assumption. We incorporate a bootstrapping approach to derive the significance levels of parameter estimates. We found that the average ratio of catch to the estimated total stock was less than 30% before the 1990s but exceeded 40% in the 1990s. After 2000, it dropped back to about 36%. This finding indicates that mackerel may have been over-fished in the 1990s, but the government regulations introduced in the 2000s alleviated over-fishing problems. Nevertheless, our dynamic optimization analysis suggests that the total allowable catch may need to be carefully controlled to achieve socially optimal management of resources.

• The Journal of the Convergence on Culture Technology
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• 제4권4호
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• pp.123-133
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• 2018

This study aimed to suggest basic data required to improve the awareness of physical therapy and examine physical therapists' awareness of the independent establishment of physical therapy clinics. To do so, 175 physical therapists in Gyeongnam areas were surveyed. Their general characteristics were statistically analyzed using SPSS 10.0, and their current workplace, working conditions and job satisfaction were analyzed using chi square distributions. The awareness of independent establishment was analyzed using the Excel program. The statistical significance (a) in this study was set at 0.05. Their interest in physical therapy was surveyed by gender, and 52.2% of males showed interest, higher than that of females. The satisfaction level of those who work in general hospitals with self-development was 32.8%, higher than that of those who work in clinics. To the question about independent establishment, 83.4% agreed to independent establishment, and 57.5% answered that the first thing to do before independent establishment is acquiring professional theoretical knowledge and clinical treatment skills. In terms of the areas of establishment, 45.2% answered physical therapy for the musculoskeletal system, and 39.7% answered that the awareness of doctors is the biggest obstacle to independent establishment. It will be necessary to ensure physical therapists acquire professional theoretical knowledge and clinical treatment skills and to improve awareness between physical therapists and doctors. In addition, it is considered that departments related to physical therapy need to be unified as a four-year course, and the independent establishment of physical therapy clinics is required to be legalized.

• Korean Journal of Food Science and Technology
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• 제51권3호
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• pp.214-220
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• 2019

Four rice varieties (Boseogchal for waxy, Baegjinju for medium-waxy, and Seolgaeng and Haiami for non-waxy) were milled to 2% degree of milling (DOM), and physicochemical and sensory properties of 2% milled rice (2% MR) were compared to those of brown rice (BR). No significant differences in the approximate compositions of BR and 2% MR were observed, whereas the grain color of 2% MR was slightly brighter than that of BR. For all varieties, water absorption ratio of BR was significantly increased by milling. The pasting properties of rice varied significantly depending on the variety, but there was no significant difference in peak and through viscosities between BR and 2% MR. Analysis of the texture of cooked rice showed that milling to 2% DOM caused a significant decrease in hardness, but an increase in adhesiveness and stickiness. Cooked Seolgaeng 2% MR scored significantly higher in the sensory evaluation than the corresponding BR. These results suggest that 2% DOM would be useful for improving the sensory properties of cooked non-waxy rice.

• Journal of the Korean GEO-environmental Society
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• 제12권9호
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• pp.55-61
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• 2011

This study investigate the use of ultraviolet(UV) light with hydrogen peroxide($H_2O_2$) for Methyl Tert Butyl Ether(MTBE) degradation in photolysis reactor. The process in general demands the generation of OH radicals in solution at the presence of UV light. These radicals can then attack the MTBE molecule and it is finally destroyed or converted into a simple harmless compound. The MTBE removal by photolysis were mathematically described as the independent variables such as irradiation intensity, initial concentration of MTBE and $H_2O_2$/MTBE ratio, and these were modeled by the use of response surface methodology(RSM). These experiments were carried out as a Box-Behnken Design(BBD) consisting of 15 experiments. Regression analysis term of Analysis of Variance(ANOVA) shows significantly p-value(p<0.05) and high coefficients for determination values($R^2$=94.60%) that allow satisfactory prediction of second-order regression model. And Canonical analysis yields the stationery point for response, with the estimate ridge of maximum responses and optimal conditions for Y(MTBE removal efficiency, %) are $x_1$=25.75 W of irradiation intensity, $x_2$=7.69 mg/L of MTBE concentration and $x_3$=11.04 of $H_2O_2$/MTBE molecular ratio, respectively. This study clearly shows that RSM is available tool for optimizing the operating conditions to maximize MTBE removal.

• Informatization Policy
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• 제27권4호
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• pp.85-100
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• 2020

The purpose of this study is to investigate how level of digital information usage of the middle-aged or elderly people affects life satisfaction and whether social capital mediates the relationship between level of digital information usage and life satisfaction. In this study, we analyzed data of 1,661 people aged 55 or older from the 「2018 Survey on Digital divide」 by the National Information Society Agency. The SPSS 25.0 statistical package was used for the mutiple regression analysis and Baron and Kenny(1986)'s steps for mediation. The statistical significance of the mediated effects of social capital was verified by the Sobel Test. As a result of the analysis, the aged people have a higher life satisfaction when they are women and older, do not live alone, have higher levels of digital informatization usage and social capital. In addition, social capital also revealed to have a mediating role between level of digital information usage and life satisfaction. This shows that social capital needs to be considered along with the level of digital information usage as a way to improve life satisfaction of the middle-aged or the elderly people.

• The Mathematical Education
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• 제62권2호
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• pp.289-302
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• 2023

In today's digital information society, student knowledge and skills to analyze big data and make informed decisions have become an important goal of school mathematics. Integrating big data statistical projects with digital technologies in high school <Artificial Intelligence> mathematics courses has the potential to provide students with a learning experience of high impact that can develop these essential skills. This paper proposes a set of guidelines for designing effective big data statistical project-based tasks and evaluates the tasks in the artificial intelligence mathematics textbook against these criteria. The proposed guidelines recommend that projects should: (1) align knowledge and skills with the national school mathematics curriculum; (2) use preprocessed massive datasets; (3) employ data scientists' problem-solving methods; (4) encourage decision-making; (5) leverage technological tools; and (6) promote collaborative learning. The findings indicate that few textbooks fully align with these guidelines, with most failing to incorporate elements corresponding to Guideline 2 in their project tasks. In addition, most tasks in the textbooks overlook or omit data preprocessing, either by using smaller datasets or by using big data without any form of preprocessing. This can potentially result in misconceptions among students regarding the nature of big data. Furthermore, this paper discusses the relevant mathematical knowledge and skills necessary for artificial intelligence, as well as the potential benefits and pedagogical considerations associated with integrating technology into big data tasks. This research sheds light on teaching mathematical concepts with machine learning algorithms and the effective use of technology tools in big data education.

• Journal of the Korean earth science society
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• 제36권2호
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• pp.171-180
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• 2015

Regarding the tropical cyclone (TC) genesis frequency, TCs between 1999 and 2013 were generated more frequently in the northwest waters of the tropical- and subtropical western North Pacific than TCs between 1977 and 1998. TCs over the period from 1977-1998 showed a northward track trend generated mostly from the distant sea in east of the Philippines via the mainland of the Philippines and the South China Sea to the west toward Indochina or from the distant sea in east of the Philippines to the distance sea in east of Japan. TCS over the period from 1999-2013 showed a northward shift pattern to the mid-latitude region mostly in East Asia. Therefore, TCs over the period from 1999-2013 tended to move to much higher latitudes than TCs over the period from 1977-1998, which also resulted in the high possibility of maximum TC intensity occurred in higher latitudes during the former period than the latter period. In the difference of 500 hPa streamline between two periods, the anomalous anticyclonic circulations were strengthened in $30-50^{\circ}N$ whereas the anomalous monsoon trough was placed in north of the South China Sea, which was extended to the east up to $145^{\circ}E$. The mid-latitude in East Asia is affected by the anomalous southeasterlies due to the above anomalous anticyclonic circulations and anomalous monsoon trough. The anomalous southeasterlies play a role in anomalous steering flows that directed TCs to the mid-latitude regions in East Asia, which made the latitudes of the maximum intensities in TCs over the period from 1999 - 2013 further to the north than those in TCs over the period from 1977-1998.

• Journal of Nutrition and Health
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• 제9권1호
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• pp.92-98
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• 1976

The present studies were carried out to observe the nutritional effects of three kinds of locally produced dried infantile formula milk (DFM) and one fermented milk (FM). A feeding trial with 60 male growing albino rats weighing $60{\sim}70$ grams was conducted during 6 weeks to compare the nutritive values and protein qualities of three DFM and a FM. The diet treatments consisted of 100% control diet, 70% control diet plus 30% DFM-A, 70% control diet plus 30% DFM-B, 70% control diet plus 30% DFM-C, 100% control diet with FM and 70% control diet plus 30% DFM-B with FM. The items investigated were body weight gain, feed intake, feed efficiency ratio (FER), various organ weights, protein efficiency ratio (PER), digestibility of nutrients, biological value, utilizability of protein and intestinal microbial changes of albino rats. The results obtained are summarized as follows; 1. Although there was no statistical significance, rats fed diets containing DFMs and FM gained faster than the rats fed control diet. The best growth rate was obtained with the DFM-A and DFM-C groups. In spite of the lower protein contents of the three DFM diets than the control diet, the growth rate of albino rats fed the DFM diets was somewhat improved than rats fed control diet. 2. No statistical significance was found in feed consumption but the trend was that the feed intake of control group was higher than those of the DFM diet group. 3. Feed efficiency was inproved significantly (p<0.01) by feeding DFMs as compared with control diet. DFM-A group showed the best FER, although no statistical significance was found. 4. Rats fed the DFM diets showed significantly (p<0.01) higher PER as compared with those of the control group. But no difference was found anions DFM groups. The significant improvement (p<0.01) of PER due also to the feeding of FM was seemed to be brought about by the beneficial effect of FM. 5. The present data revealed that feeding DFM and FM didn't affect the weights of various organs of rats. 6. The protein digestibility of experimental diets was similar to each other. Although no statistical significance was found among treatments, the DFMs and FM surely tended to improve the biological value and utilizability of protein. 7. Microbial study indicated that among intestinal flora FM fed group, there were more Lactic acid bacteria than E. coli. From the experimental results described above, it may be concluded that the nutritive effects of three kinds of locally produced DFMs are much alike and the growth rate of growing albino rats can be improved by feeding either DFM or FM due to their beneficial effects on the feed efficiency and protein utilization.

• Journal of Korean Society of Forest Science
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• 제38권1호
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• pp.33-45
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• 1978

The purpose of present study is to analyze the genetic variation of natural stand of Pinus densiflora. In 1975 following after the selection of 1974, twenty trees from each of three natural populations of the species were selected and their open-pollinated seeds were collected, and the locations and conditions of the populations ate presented in table 1, 2 and figure 1. Some morphological traits of the populations were already detailed in our second report of this series, in which Myong-Ju and Ul-Jin populations were regarded to be superior phenotypically to suweon population. The morphological traits of cone, seed and seed-wing, and also the growth performances and needle characters of the seedling were observed in the present study according to the previous methods. The results obtained are summarized as follows; 1. The meteorological data obtained by averaging the records of 30 year period (1931~1960) measured from the nearest meteorological stations to each population are shown in fig.2, 3, 4. The distributional patterns of investigated climate factors are generally considered to be similar among the locations. However, the precipitation density during growing season and the air temperature during dormant season on Suweon area, population 6, were quite different from those of the other areas. 2. The measurements of fresh cone weight, length, diameter and cone index, i.e., length to diameter ratio are presented in table 7. As shown in table 7, all these traits except for cone diameter seem to be highly significant in population differences and family differences within population. 3. The morphological traits of seed and seed-wing are detailed in table 8, 9, and highly significant differences are recognized among the populations and the families within population in seed-wing length, seed-wing index, seed weight, seed-length and seed index but not among the populations in the other observed traits. The values of correlation coefficient between the characters of cone and seed are given in table 10 and the positive significant correlations can be observed in the most parts of the compared traits. 4. Significant statistical differences among populations and families within population are observed in the growth performances of 1-0 and 1-1 seedling height of these progenies. But the differences in root collar diameter are shown only among families within population. As shown in table 13, the most parts of correlations are not significant statistically between the growth performances of seedling and the seed characters. 5. The number of stomata row on both sides of needle and the serration density were measured in the seedlings from each of the families of the three populations. As shown in table 15, statistical differences are considered to be significant among the populations and among the families within population in serration density but not among the populations in stomata row on both sides of the needle. The results differ from those of the third report of this series. Even if one of the reason seems to be the diversity of selected populations, it could not be confirmed definitely. The correlations between progenies and parents are not generally observed in the investigated traits of needle as shown in table 16.

• Tuberculosis and Respiratory Diseases
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• 제40권2호
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• pp.135-146
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• 1993

Background: In acute pulmonary embolism it has been postulated that the constriction of bronchi and pulmonary artery secondary to neurohumoral response plays an important role in cardiopulmonary dysfunction in addition to the mechanical obstruction of pulmonary artery. Serotonin is considered as the most important mediator. Positive end expiratory pressure (PEEP) stimulates $PGI_2$ secretion from the vascular endothelium, but its role in acute pulmonary embolism is still in controversy. Methods: To study the cardiopulmonary effect and therapeutic role of Ketanserin, selective antagonist of 5-HT2 receptor, and PEEP in acute pulmonary embolism experimental acute pulmonary embolism was induced in dogs with autologous blood clot. The experimental animals were divided into 3 groups, that is control group, Ketanserin injection group and PEEP application group. Results: Thirty minutes after embolization, mean pulmonary arterial pressure and pulmonary vascular resistance increased and cardiac output decreased. $PaO_2,\;P\bar{v}O_2$ and oxygen transport decreased and physiological shunt and $PaCO_2$ increased. After injection of Ketanserin, comparing with control group, mean pulmonary arterial pressure, pulmonary vascular resistance and physiological shunt decreased, while cardiac output, $PaO_2$ and oxygen transport increased. All these changes sustained till 4 hours after embolization. After PEEP application pulmonary vascular resistance, $PaO_2$ and $PaCO_2$ increased, while physiological shunt, cardiac output and oxygen transport decreased. After discontinuation of PEEP, mean pulmonary arterial pressure and pulmonary vascular resistance decreased and were lower than control group, while $PaO_2$ and cardiac output increased and higher than control group. $PaCO_2$ decreased but showed no significant difference comparing with control group. Conclusion: It can be concluded that Ketanserin is effective for the treatment of acute pulmonary embolism. With PEEP hemodynamic status deteriorated, but improved better than control group after discontinuation of PEEP. Thus PEEP may be applied carefully for short period in acute pulmonary embolism if the hemodynamic status is tolerable.