• The Journal of the Acoustical Society of Korea
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• v.43 no.1
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• pp.9-18
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• 2024

The importance of active sonar systems is emerging due to the quietness of underwater targets and the increase in ambient noise due to the increase in maritime traffic. However, the low signal-to-noise ratio of the echo signal due to multipath propagation of the signal, various clutter, ambient noise and reverberation makes it difficult to identify underwater targets using active sonar. Attempts have been made to apply data-based methods such as machine learning or deep learning to improve the performance of underwater target recognition systems, but it is difficult to collect enough data for training due to the nature of sonar datasets. Methods based on mathematical modeling have been mainly used to compensate for insufficient active sonar data. However, methodologies based on mathematical modeling have limitations in accurately simulating complex underwater phenomena. Therefore, in this paper, we propose a sonar signal synthesis method based on a deep neural network. In order to apply the neural network model to the field of sonar signal synthesis, the proposed method appropriately corrects the attention-based encoder and decoder to the sonar signal, which is the main module of the Tacotron model mainly used in the field of speech synthesis. It is possible to synthesize a signal more similar to the actual signal by training the proposed model using the dataset collected by arranging a simulated target in an actual marine environment. In order to verify the performance of the proposed method, Perceptual evaluation of audio quality test was conducted and within score difference -2.3 was shown compared to actual signal in a total of four different environments. These results prove that the active sonar signal generated by the proposed method approximates the actual signal.

• Journal of Animal Science and Technology
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• v.45 no.6
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• pp.1067-1078
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• 2003

This study was designed to determine the effect of gestation housing and parity on the farrowing performance and behaviour of sows during pregnancy, farrowing and lactation periods. Total 18 Duroc sows were randomly assigned after 4 weeks of gestation to either an individual gestation stall or a groups of three with pen gestation system for three parities(1st, 2nd${\sim}$3rd, and 4th${\sim}$5th). Approximately 7 days before predicted farrowing date, sows were transferred to farrowing crates where they remained until 21 days post-partum. Behaviour was recorded on day 60 and 90 of pregnancy for 24 hours, on day of farrowing for farrowing duration and on day 10 of lactation for 2.5 hours in the farrowing crate. The results obtained from this study were summarized as follows: On 60 and 90 day of pregnancy, all sows in both groups made attempts for ventral lying more than for other postures. Sows in the group gestation pen spent more time on walking than those in individual gestation stall(p<0.01); however, the group housed sows were spent less time on drinking than the individually housed sows(p<0.01). There was no significant difference between gestation housings in the occurrence of stereotypy of pregnant sows. On day 60 of pregnancy, sows in the individual gestation stall showed the highest frequency of vacuum chewing and head weaving. However, floor licking and bar licking behaviours were highest in day 90 pregnant sows individually housed. The sows individually housed during the gestation period spent more time on sitting and eating on the day of farrowing in the farrowing crate than the sows group housed. On day 10 of lactation in the farrowing crate, the group housed sows during the gestation period made significantly more attempts for ventral lying than sows individually housed. In conclusion, the occurrence of stereotypy of sows during the gestation and lactation did not differ between gestation housings and farrowing performance of sows during the gestation period was not affected by gestation housing. Thus, the group housing for pregnant sows is a feasible means to improve welfare of sows and to increase the normal behaviour of sows.

• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.3
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• pp.1-11
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• 2013

This study investigated Chinese Laws on the kind of urban green spaces and the legal requirements for the green spaces of urban habitat and analyzed the specificities of them intending to provide basic data to suggest bringing in or not the relevant Chinese Laws to Korea. This study can be summarized as follows: First, the concept of Chinese urban green spaces(g.s.) classified by 5 kinds(park g.s., production g.s., protection g.s., attachment g.s., the others g.s.) placed the park and green spaces in the same category unlike the Korean urban green spaces that only distinguishes between park and green spaces. The Chinese Urban Park is classified by 4 kinds(composite park, community park, special park, linear park) at the 'Standard for urban green spaces classification' which is below in rank of the legal system. Second, in case of calculation for green spaces ratio of urban green spaces in China, the green rooftop landscaping area should not be included as a green spaces area except the rooftop of a basement or semi basement building to which residents have easy access. The green spaces requirements and compulsory secure ratio by 3 habitat kinds(habitat, small habit, minimum habitat) of when to act as a residential plan is regulated. Third, the green spaces system is obligated to establish at habitat green spaces plan and is specified to conserve and improve existing trees and green spaces. The green spaces ratio on reconstruction for old habitat is relaxed to be lower than for new habitat and a gradient of green spaces is peculiarly clarified. The details and requirements for establishment and the minimum area intending for each classes of the central green spaces(habitat park, children park, minimum habitat's green spaces) are regulated. Especially at a garden style of minimum habitat's green spaces, intervals between the south and north houses and a compulsory security for green spaces area classifying into two groups(closing type green spaces and open type green spaces) by a middle-rise or high-rise building are clarified. System of calculation for green spaces area is presented at a special regulation. Fourth, a general index(area/person) of public green spaces within habitat to achieve by 3 habitat kinds is determined, in this case, the index on reconstruction for a deterioration zone can be relaxed to be lower to the extent of a specified quantity. A location and scale, minimum width and minimum area per place of public green spaces are regulated. A space plot principle including adjacent to a road, greening area ratio against total area, security of open space and the shadow line boundary of sunshine are also regulated to intend for public green spaces. Fifth, the minimum horizontal distance between the underground cables and the surrounding greening trees are regulated as the considerable items for green spaces when setting up the underground cables. The principle to establish green spaces within public service facilities is regulated according to the kind of service contents. It shall be examined in order to import or not the special regulations that only exist in Chinese Laws but not in Korean Laws. The result of this study will contribute to gain the domestic landscape architect's' sympathy of the research related to Chinese urban green spaces laws requiring immediate attention and will be a good chance to advance into the internationalization of Korean Landscape Architectural Laws.

• Journal of the Korean Society of School Health
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• v.2 no.1
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• pp.58-90
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• 1989

This study was attempted to contribute to the development of school health by providing the basic data about the distribution basis and distribution aspect of teachers holding additional school health that are in charge of school health business in parimary schools, middle schools and high schools without any nurse-teacher. This study analyzed literatures about the history, related laws, organization and professional manpower of school health. The emphasis was set on the distribution basis of theachers holding additional school health. The results of this study are as following: 1. The school health of the world dates to the late 18th century in Europe where was free supplying with food for poor children. The school health of Korea orginated from smallpox vaccination which was executed with appearance of modern schools in the late 19th century. 2. The related laws of school health began as a part of Education Law with was constituted in 1949. By the School Health Law constituted in 1967 and the enforcement ordinance of School Health made firm the legal basis of school health. 3. The administrative organs of school health are the Ministry of Education in center and each Board of Education in cities and provinces. For the first time in 1979, the department of school health was established in the organization of the Ministry of Education. And at about the same time of establishment of the department of school health, health section was established in the department of social physical-training in locality. 4. In the manpower of school health which was presented in the related statute of school health, there are the ward chief of education, the superintendent of educational affair, of cities and districts, the mayors, the governors of provinces, the school managers, the principals, the school doctors, the school pharmacists, and the nurse-teachers, including teachers holding additional school health as the practical manpower of school health. 5. In order to get some information on distribution aspect of teachers additional school health, this study made up a questionnaire from August 3 to August 11, 1988. The subjects of this study were 212 leachers who took part in the yearly training for teachers holding additional school health from Kyunggi province, Chungbuk province and Jeonbuk province. The results of the questionnaire are as following: 1. The distribution percentages of teachers holding additional school health according to each Board of Education wich schools are subject to, are as following:70.1% (Kyunggi), 76.5% (Chungbuk), and 81.4% (Jeonbuk). There was a significant difference. The distribution percentages of teachers holding additional school health according to the school levels of 3 provinces are as following: 74.1% (Primary schools), 77.8% (Middle schools), 76.7% (High schools). There were little significant differences. 2. The distribution according to the general characteristics of the subject schools: There were 64.2 percent of primary schools and 35.8 percent of middle schools among 212 schools. 91. 5 percent of schools were located in districts. Public schools formed 55.7% and then national schools were higher in percentage than private schools. 58.5 percent of schools had 1-9 classes, 64.6 percent of schools had 101-500 students, and 90 percents of schools had 1-20 teachers. In considering student sex, the coed school showed the high distribution percentage (Primary schools : 100%, Middle schools: 81.6%). 3. The distribution according to the characteristics of teachers holding additional school health: 93.3 percent of teachers were female, and more than 60 percent of teachers were 20-29 years old. As the age got higher, the percentage became lower. There were little significant differences by marital status. In considering their educational status, 86.8 percent of teachers in primary schools were from teacher's colleges, and 64.5 percent of teachers in middle schools were from education colleges. In considering teaching career, 46.7 percent of teachers had teaching career of less than 2 years. 73.6 percent of teachers had held additional school health for less than one year. More than 80 percent of teachers had participated in the training one time or twice. More than 70 percent of teachers had 1-2 additional jobs except for the school health business. The motivation to hold additional school health is most caused by mandatory order, which accounts for more than 80.0 percent. In considering interesting degree concerning school health, lukewarm answer is the highest of 62.7 percent, followed by affirmative answer of 23.6 percent. In considering their contentment degree respecting additional school health job, "discontent or very discontent"is the highest of 47.6 percent. As a descontent reason of additional school health job, overwork is the highest factor of 37.9 percent. Among addiitional school health job, the most difficult affair is nursing service to be 34.0 percent, followed by health education of 31.6 percent. It testify the need of professional. The source of knowledge about school health has been acquired from masscommunication or private health experience, which account for as much as 56.1 percent. It shows seriousness of lack of professionalism. With regard to neccessity of school health experts, 95.8 percent represents absolute need. With above consideration of study results, I propose as follows : 1. I propose that the authorities concerned unify and improve statute respecting current school health which has not been steadfastly supporting school health business by ambiguity of expression and dualization. 2. I propose that the authorities concerned give the school manager, school staffs and parents of students educational chance with which they can acknowledge the importance of school health and in which they can participate as well as set up alternative policy plan to be albe to vitalize school health committee. 3. I propose that administrative organization practicable to taking totally charge of school health business is established within the Ministry of Education. 4. I propose that the authorities concerned back up and cooperate in an attempt by make school health better and desirable toward development by way of appointing qualitied health teachers on the basis of legally regular teacher staffs.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.5 no.1
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• pp.69-86
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• 1969

On the growing of the interspecific hybrid ginseng plant, the phenomena of hybrid vigoures are observed in the root, stem, and leaf, but it can not produce seeds favorably since the ovary is abortive in most cases in interspecific hybrid plants. The present investigation was undertaken in an attempt to elucidate the embryological dses of the seed failure in the interspecific hybrid of ginseng (Panax Ginseng ${\times}$ P. Quinque folium). And the results obtained may be summarized as follows. 1). The vegetative growth of the interspecific hybrid ginseng plant is normal or rather vigorous, but the generative growth is extremely obstructed. 2). Even though the generative growth is interrupted the normal development of ovary tissue of flower can be shown until the stage prior to meiosis. 3). The division of the male gameto-genetic cell and the female gameto-genetic cell are exceedingly irregular and some of them are constricted prior to meiosis. 4). At meiosis in the microspore mother cell of the interspecific hybrid, abnormal division is observed in that the univalent chromosome and chromosome bridge occure. And in most cases, metaphasic configuration is principally presented as 23 II+2I, though rarely 22II+4I is also found. 5). Through the process of microspore and pollen formation of F1, the various developmental phases occur even in an anther loclus. 6). Macro, micro and empty pollen grains occur and the functional pollen is very rare. 7). After the megaspore mother cell stage, the rate of ovule development is, on the whole, delayed but the ovary wall enlargement is nearly normal. 8). Degenerating phenomena of ovules occur from the megaspore mother cell stage to 8-nucleate embryo sac stage, and their beginning time of constricting shape is variously different. 9). The megaspore arrangement in the parent is principally of the linear type, though rarely the intermediate type is also observed, whereas various types, viz, linear, intermediate, Tshape, and I shape can be observed in hybrid. 10). After meiosis, three or five megaspore are some times counted. 11). Charazal end megaspore is generally functional in the parents, whereas, in F1, very rarely one of the center megaspores (the second of the third megaspore) grows as an embryo sac mother cell. 12). In accordance with the extent of irregularity or abnormality in meiosis, division of embryo sac nuclei and embryo sac formation cause more nucellus tissue to remain within th, embryo sac. 13). Even if one reached the stage of embryo sac formation, the embryo sac nuclei are always precarious and they can not be disposed to theil proper, respective position. 14). Within the embryo sac, which is lacking the endospermcell, the 4-celled proembryo, linear arrangement, is observed. 15). Through the above respects, the cause of sterile or seed failure of interspecific hybrid would be presumably as follows, By interspecific crossing gene reassortments takes place and the gene system influences the metabolism by the interference of certain enzyme as media. In the F1 plant, the quantity and quality of chemicals produced by the enzyme system and reaction system are entirely different from the case of the parents. Generally, in order to grow, form, and develop naw parts it is necessary to change the materials and energy with reasonable balance, whereas in the F1 plant the metabolic process becomes abnormal or irregular because of the breakdown of the balancing. Thus the changing of the gene-reaction system causes the alteration of the environmental condition of the gameto-genetic cells in the anther and ovule; the produced chemicals cause changes of oxidatio-reduction potential, PH value, protein denaturation and the polarity, etc. Then, the abnormal tissue growing in the ovule and emdryo sac, inhibition of normal development and storage of some chemicals, especially inhibitor, finally lead to sterility or seed failure. Inconclusion, we may presume that the first cause of sterile or seed abortion in interspecific hybrids is the gene reassortment, and the second is the irregularity of the metabolic system, storage of chemicals, especially inhibitor, the growth of abnormal tissue and the change of the polarity etc, and they finally lead to sexual defect, sterility and seed failure.

• Journal of The Korean Society of Grassland and Forage Science
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• v.5 no.1
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• pp.22-32
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• 1985

Optimum pasture management during the summer season is an important factor to maintain good regrowth and persistence of pasture in Korea. This experiment was carried out to investigate the effects of the cutting management on the dead plant, weed appearance, regrowth and carbohydrate reserves in stubble, and dry matter yield of tall fescue dominated pasture during the mid summer season. For the test, a split plot design with 4 replications was treated with 2 different the third cutting times (July 12 and Aug. 4) as the mainplots, and 3 different cutting heights (3, 6 and 9 cm) at the third cut as the subplots, and the experiment was done at the experimental field of the Livestock Experiment Station, in Suweon, 1984. The results obtained are summarized as follows: 1. Considering the meteorological conditions during the experimental period, the temperature was a little higher by $2^{\circ}C$ than that of average year, especially the first and second decade of August were high. And the precipitation of 1984 tended to be low when compared with the average year. 2. Temperature of soil surface and underground tended to increase by $1-3^{\circ}C$ as the stubble height was low during the summer season. 3. Regrowth leaf length and leaf area after the third cut increased significantly with the high cutting height at the third cut. 4. A significant higher total nonstructural carbohydrate (TNC) content in stubble after the third cut was observed in the high stubble cut on July 12. The results indicate that the high stubble height reserves more carbohydrates for early regrowth stage after the third cut when compared with the low stubble. On Aug. 4, however, the recovery of TNC contents after the third cut was not effective due to high temperature and rainfall. 5. The percentage of dead plant after the third cut was found to be high with the low cutting height during the mid summer season (p<0.05). 6. With the low stubble height on July 12 cut, it was appeared that the percentage of weed was significantly increased (p<0.05), and main weeds appeared after the third cut were Echinochloa crusgalli>Digitaria sanguinalis>Cyperus iria>Rumex crispus, and so on. In case of cut on Aug. 4, weed appearance was no difference at three cutting heights. 7. Dry matter yield at the third cut was increased in the plot of cutting on Aug. 4 and stubble height (p<0.05). However, yields at the fourth and fifth cut were increased with high stubble height (p<0.05), regardless of harvest time. 8. In total dry matter yield after the third cut, there was no significant difference between the cutting time and forage yield. However, total yield on July 12 was increased with the high stubble height (p<0.05). 9. From the above results, it is suggested that the 9 cm cutting height during the mid summer season is the most effective for good regrowth, weed control and forage yield of tall fescue dominated pasture.

• Journal of The Korean Society of Grassland and Forage Science
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• v.6 no.2
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• pp.103-110
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• 1986

The experiments were carried out to study the influence of meteorological factors and cutting management on dry matter accumulation and net energy value in orchardgrass (Dactlylis glomerata L.) cv. Potomac and Baraula, perennial ryegrass (Lolium perenne L.) cv. Reveille and Semperweide and meadow fescue (Festuca pratensis Huds.) cv. Cosmos 11 and N.F.G.. The field trials were designed as a split plot design with three cutting regimes of 6-7 cuts at grazing stage, 4-5 cuts at silage stage and 3 cuts at hat stage in Korea and West Germany from 1975 to 1979. The results obtained are summarized as follows: 1. Productivity of orchardgrass, perennial ryegrass and meadow fescue were mainly affected by cutting systems and meteorological factors, especially air temperature, rainfalls, solar radiation and their interactions. In West Germany, cutting frequency was to be found asan most important factor influenced to dry matter yield and net energy value. 2. Orchardgrass, taken as average of all experimental sites in Korea, produced high yield of 875 kg/10 a in dry matter, which was as much as 32% and 27% higher than those of perennial ryegrass and meadow fescue, respectively. The annual dry matter yields of orchardgrass from 1976 to 1977 were shown a little variation. Dry matter yields in Freising and Braunschweig in West Germany were increased in all grass species continuously. 3. Orchardgrass, perennial ryegrass and meadow fescue showed different response to cutting frequency. The highest dry matter yields were found under 3 cuts at hay stage for orchardgrass and 4-5 cuts at silage stage for perennial ryegrass and meadow fescue. In West Germany, dry matter yields, as average of all grass species under different cutting systems, were 1326 kg, 1175 kg and 1098 kg/10a for 3 cuts, 4-5 cuts and 6-7 cuts, respectively. 4. Chemical composition and net energy concentration of temperate grasses were influenced by cutting managements. The highest yields of digestible crude protein were obtained under 6-7 cuts at grazing stage both in Korea and West Germany. In net energy yields, 3 cutting system produced the highest yield with 694 (orchardgrass), 665 (perennial ryegrass) an 623 kStE/10 a (meadow fescue). However, frequent cutting at grazing and silage stage produced higher yields than 3 cuts at hay stage in Cheju, Suweon and Taekwalyong.

• Journal of Korean Society of Forest Science
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• v.84 no.4
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• pp.465-478
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• 1995

The objective of this study was to investigate the impacts of large-scale timber harvesting on the environment of a mature hardwood forest. To achieve the objective, the effects of harvesting on forest environmental factors were analyzed quantitatively using the field data measured in the study sites of Seoul National University Research Forests [(Mt.) Paekunsan] for two years(1993-1994) following timber harvesting. The field data include information on vegetation, soil mesofauna, physicochemical characteristics of soil, surface water runoff, water quality in the stream, and hillslope erosion. For comparison, field data for each environmental factor were collected in forest areas disturbed by logging and undisturbed, separately. The results of this study were as follows : The diversity of vegetational species increased in the harvested sites. However, the similarity index value of species between harvested and non-harvested sites was close to each other. Soil bulk density and soil hardness were increased after timber harvesting, respectively. The level of organic matter, total-N, avail $P_2O_5$, CEC($K^+$, $Na^+$, $Ca^{{+}{+}}$, $Mg^{{+}{+}}$) in the harvested area were found decreased. While the population of Colembola spp., and Acari spp. among soil mesofauna in harvested sites increased by two to seven times compared to those of non-harvested sites during the first year, the rates of increment decreased in the second year. However, those members of soil mesofauna in harvested sites were still higher than those of non-harvested sites in the second year. The results of statistical analysis using the stepwise regression method indicated that the diversity of soil mesofauna were significantly affected by soil moisture, soil bulk density, $Mg^{{+}{+}}$, CEC, and soil temperature at soil depth of 5(0~10)cm in the order of importance. The amount of surface water runoff on harvested sites was larger than that of non-harvested sites by 28% in the first year and 24.5% in the second year after timber harvesting. The level of BOD, COD, and pH in the stream water on the harvested sites reached at the level of the domestic use for drinking in the first and second year after timber harvesting. Such heavy metals as Cd, Pb, Cu, and organic P were not found. Moreover, the level of eight factors of domestic use for drinking water designated by the Ministry of Health and Welfare of Korea were within the level of the first class in the quality of drinking water standard. The study also showed that the amount of hillslope erosion in harvested sites was 4.77 ton/ha/yr in the first year after timber harvesting. In the second year, the amount decreased rapidly to 1.0 ton/ha/yr. The impact of logging on hillslope erosion in the harvested sites was larger than that in non-harvested sites by seven times in the first year and two times in the second year. The above results indicate that the large-scale timber harvesting cause significant changes in the environmental factors. However, the results are based on only two-year field observation. We should take more field observation and analyses to increase understandings on the impacts of timber harvesting on environmental changes. With the understandings, we might be able to improve the technology of timber harvesting operations to reduce the environmental impacts of large-scale timber harvesting.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.12
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• pp.2049-2067
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• 2013

The purpose of this study is to present a more effective nutrition education activation plan. As a result of investigating the dietary education operating situation, 58.9% underwent direct education, and 89.5% underwent food life education through traditional food culture succeeding business operation. The results from investigating the recognition regarding dietary education are as follows. The activation level by education types was as low as 2.24 points, the necessity was as high as 4.54 points, the difficult point in performing food life education was 'overwork' with 4.43 points, and the teaching activity ability level was 'can effectively prepare a teaching guidance plan' at 2.96 points. As a result of investigating the nutrition consultation operating situations, 62.8% underwent it and all of the students as well as some parents and teachers performed it. The consumed time per consultation for effective nutrition consultation was 10~20 minutes, the required education equipment and data were 'consultation program' with 40.3%, and the important content during consultation was 'contents related to eating habits' with 70.5%, which was recognized as the most important.

• Korean Journal of Poultry Science
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• v.35 no.4
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• pp.375-380
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• 2009

This study was conducted to investigate the effect of feeding induced molting on the visceral organs and blood component profile in laying hens and designed to test 400 flocks of 60 week old Leghorn laying hens for 34 weeks. A total of four molting treatment methods by including the molted with customary molting by fasting method (c), feeding single diet of corn (T1), feeding single diet of wheat bran (T2) and feeding single diet of alfalfa meal (T3) were tested, and each treatment was repeated for 5 times, and 20 laying hens were randomly assigned in an cage for each repeat. As the result of the experiment, ovary was $2.03{\sim}6%$ and oviduct was $2.51{\sim}3.47%$ in visceral organs for body weight at pre-molting term, but there was no significant difference. At post-molting, no significant difference was found, ovary was $0.25{\sim}0.41%$, uterus of control, T1, T2 and T3 was 1.12%, 0.82%, 0.48% and 0.90%, respectively. T2 was significantly lower than control, T3 (p<0.05) at the 50% of egg production. Ovary was $2.20{\sim}2.60%$ and oviduct was $2.98{\sim}3.45%$. In addition, ovary was $2.65{\sim}3.01%$, oviduct was $3.23{\sim}3.64%$ at the peak egg production, but there was no significant difference by non-feeding and feeding molting treatments. In blood component profile, cholesterol was $179.8{\sim}245.7\;mg/dL$ at pre-molting, but there was no significant difference and at post-molting, concentration of cholestrol in control, T1, T2 and T3 was 353.6, 229.1, 261.8 and 300.6 mg/dL, respectively. T1 was significantly lower than control and T3 (p<0.05). In addition, first laying day was $228.1{\sim}271.8\;mg/dL$, 50% of egg production was $236.5{\sim}284.8\;mg/dL$, there was no significant difference. Concentration of cholestrol in control, T1, T2 and T3 was 324.1, 591.6, 363.0 and 315.6 mg/dL, respectively, at the peak egg production period. T1 was significantly higher than other treatment (p<0.05).