• Journal of the Korean Institute of Landscape Architecture
• /
• v.42 no.6
• /
• pp.1-9
• /
• 2014

Within the urban area, over the past decades unused land and public land such as streams and road sides have given urban residents a space for farming (urban farms). However, because this use is illegal, farming in unused and public lands could cause conflicts between urban farm users and land owners, degrade the quality of the urban landscape and contaminate the environment. Therefore, the purpose of this study is to provide a way of legalizing these farming practices that have been cultivated in unused urban areas and public lands. This study analyzed the status of distribution and use of the urban farms that have been scattered around urban areas in many different forms. The survey was conducted through on-the-spot investigation and in-person interviews with farm users and those who were operating weekend farms in the Siji region of Daegu Metropolitan City. According to the results of this study, urban farms were mainly found in green areas that were easily accessible from residential districts and prohibited from development. It was also revealed that the nearer to the border of the residential districts the sites of urban farms were, the larger the number of urban farms was. When it comes to the type of land use, although the proportion of urban farms located in farmlands was very high, the proportion of those located on state-owned lands such as roads, railroads and streams was also high, over 1/3 of that of the former sites. Among the users of urban farms, the percentage of users who were farming private-owned land for free was highest and that of state-owned land without permission ranked second. Most people who were farming unused lands or state-owned lands without permission, such as streams, roads, railroads, were the elderly. This shows the potential of farms in urban area as leisure activities spaces for the elderly. Even though this study has limitations in that the survey target area was selected in a certain area and the sizes of all urban farms were not measured by surveying apparatus and instruments, it helps to determine the characteristics of use and distribution associated with the spaces of urban farming, and to raise the importance and necessity of legalizing urban farms cultivated illegally in public land.

• Journal of Navigation and Port Research
• /
• v.39 no.6
• /
• pp.439-450
• /
• 2015

This study objects to find characteristics in chemical tanker markets and to determine optimal chemical tanker size using a total shipping cost in main trading route of asia chemical tankers .Precedent studies of determination of the optimal ship size and case studies about chemical tankers was carried out and tried to introduce a cost model which is applicable to chemical tanker. This study is dependant on numerical analysis and involves scenario analysis to minimize sensitivity of results. This analysis shows as follows. First, 12,000DWT tanker is an optimal size on the 'Far East-Middle East' services, 9,000DWT tanker is a most competitive on the 'Far East-South East Asia' services and 3,000DWT tanker is a most economic size on the 'Inner Far East' services at average market situation. Second, the bigger size of chemical tanker, the more competitive advantage the tanker will obtain when bunker fuel prices rise. Small size ship gets more competitive during bunker prices down. Third, market fluctuation of time charter rate for chemical tanker is less than 20% against its average time charter hire which means less volatile. And tanker's competitiveness per each size is remained mostly same when time charterer rates rise at same proportion. Fourth, bigger size chemical tankers have cost advantages when tanker's quantity of each part cargo increase. And small-sized tanks are more competitive when part cargo scales decrease. For the last, ship's port stay strongly influences on the determination of the optical tanker size. When vessel has shorter port stay, bigger-sized tanker will be more competitive and even can be competitive if applies in short voyage as well.

• Journal of KIISE:Computer Systems and Theory
• /
• v.30 no.5_6
• /
• pp.324-329
• /
• 2003

The public-key cryptosystems such as Diffie-Hellman Key Distribution and Elliptical Curve Cryptosystems are built on the basis of the operations defined in GF(2$^{m}$ ):addition, subtraction, multiplication and multiplicative inversion. It is important that these operations should be computed at high speed in order to implement these cryptosystems efficiently. Among those operations, as being the most time-consuming, multiplicative inversion has become the object of lots of investigation Formant's theorem says $\beta$$^{-1}$ =$\beta$$^{2}$sup m/-2/, where $\beta$$^{-1}$ is the multiplicative inverse of $\beta$$\in$GF(2$^{m}$ ). Therefore, to compute the multiplicative inverse of arbitrary elements of GF(2$^{m}$ ), it is most important to reduce the number of times of multiplication by decomposing 2$^{m}$ -2 efficiently. Among many algorithms relevant to the subject, the algorithm proposed by Itoh and Tsujii[2] has reduced the required number of times of multiplication to O(log m) by using normal basis. Furthermore, a few papers have presented algorithms improving the Itoh and Tsujii's. However they have some demerits such as complicated decomposition processes[3,5]. In this paper, in the case of 2$^{m}$ -2, which is mainly used in practical applications, an efficient algorithm is proposed for computing the multiplicative inverse at high speed by using both the factorization formula x$^3$-y$^3$=(x-y)(x$^2$＋xy＋y$^2$) and normal basis. The number of times of multiplication of the algorithm is smaller than that of the algorithm proposed by Itoh and Tsujii. Also the algorithm decomposes 2$^{m}$ -2 more simply than other proposed algorithms.

• Journal of Korean Society of Rural Planning
• /
• v.20 no.4
• /
• pp.253-262
• /
• 2014

This, an association research for design-improvement and model-development of exhibition shops at rural tourism communities, is to secure objective data by analyzing customers' awareness-tendency of and demand for agricultural-specialty exhibition shops. Survey-questions for finding out consumers' awareness-tendency and demand were determined through brainstorming of a professional council, 30 rural communities of which visit-rate by consumers is considerably high were selected for the recruit of 200 consumers. For investigation and analysis, survey and in-depth interview were carried out at the scene with the application of frequency analysis and summarization of their opinions, which revealed that they have a strong will to visit the rural tourism communities for the purchase of agricultural specialties along with the experience of learning-program and on-the-scene direct dealing and that their viewpoint on the direct dealing at the scene was very positive. Also it was confirmed hat their satisfaction with the purchase of agricultural specialties by on-the-scene direct dealing, their pleasure at the purchase, their satisfaction with services and their intention for re-purchase of them were very high while their satisfaction with the exhibition shops was very low. With on-the-scene survey, the consumers' opinions could be listened to in depth. Almost all of them said their satisfaction with the trip to those rural tourism communities was considerably high since they could go to those communities themselves to relieve the stress from their modern life, to experience healing and to see the goods on the scene. Their satisfaction also was attributed to the fact that they have enough trust in purchase along with feeling the warm-heartedness of rural residents. As to their awareness of exhibition shops, they showed a positive response to the on-the-scene direct dealing at rural communities while they, thinking that the space in those exhibition shops was not sufficiently wide, demanded for more systematic counters in more accessible and affordable exhibition shops so that they might be more satisfied with the exhibition shops. Their demand for the necessity of exhibition shops selling agricultural specialties was found to be over 80%, which indicates that the necessity is very high. As to the suitability of function, they have the opinion that the business at those shops had better be focused on sales since they have the understanding of information when they take a trip to the rural communities, while there was another opinion: since agricultural products are seasonal items they should be exhibited and sold at the same time. More than 90% of the respondents had a positive viewpoint on direct dealing of agricultural specialties on the scene, which showed that their response to it was very high. They preferred the permanent shops equipped with roll-around table-booths. In addition, it was revealed that they want systematic exhibition shops in rural communities because they frequent those communities for on-the-scene direct purchase. The preferred type and opinion resulting from estimation of consumers' demands have been reflected for development of practical designs. The structure of variable principles has been designed so that the types of display-case and table-booth might be created. The result of this study is a positive data as a design model which can be utilized at rural communities and will be commercialized for the verification of its validity.

• Journal of Chest Surgery
• /
• v.39 no.3 s.260
• /
• pp.220-225
• /
• 2006

Background: Spontaneous pneumomediastinum is an uncommon, benign, self-limited disorders that usually occurs in young adults without any apparent precipitating factors or disease. The purpose of this study was to review our experience in dealing with this entity and describe a reasonable course of assessment and management. Material and Method: A retrospective case series was conducted to identify adults patients with SPM who were diagnosed and treated in a single institution between 2001 and 2005. Result: Fifteen patients were identified who included 14 men and 1 women with a mean age of 26 years. Presenting symptoms were chest pain in 12 patients ($80\%$), dyspnea in 5 patients ($33\%$), and throat discomfort in 4 patients ($26\%$). Two cases were associated with use of inhalational drugs and 3 cases were associated with exercise. The predisposing factors were asthma, excessive exercise, and vomiting in spontaneous pneumomediastinum. The physical findings were subcutaneous emphysema in 10 patients ($77\%$). Chest radiography and computerized tomography were the diagnostic methods in all cases with CT scan revealing six cases with associated pulmonary abnormalities. Esophagogram and flexible bronchoscopy were selectively used. Fifteen patients ($100\%$) were admitted to the hospital. Their mean hospital stay was 3 days. All patients were conservatively treated. In a follow-up of 3 years no complications or recurrences were observed. Conclusion: Most simple spontaneous pneumomediastinum cases were benign diseases and most of them ($77\%$) had shown typical chest pain, dyspnea and subcutaneous emphysema. Inhalational drug use was not a major cause of SPM; however, increased use of bronchoinhalers was a suspicious cause of SPM.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.28 no.1
• /
• pp.35-42
• /
• 2018

Objectives: The objectives of this study are to research the usage characteristics of asbestos-containing building materials and to conduct exposure risk assessment by applying no. 2016-230 "Methods of Risk Assessment of Asbestos-Containing Buildings" from the Ministry of Environment. Methods: One hundred buildings located in the Seoul and Gyeonggi-Incheon area were chosen, with 29 in Seoul, 20 in Incheon, and 51 in Gyeonggi-do Province. The year of construction was divided between three buildings in the 1970s, 11 buildings in the 1980s, 42 buildings in the 1990s, and 44 buildings in the 2000s. The bulk samples were analyzed by using a polarizing microscope after a pre-process using a stereomicroscope in a hood with an HEPA filter. This study defined ACMs(asbestos-containing materials) as asbestos when the content percentage was over 1% in the analysis result. Methods and standards of risk assessment of asbestos-containing building materials were conducted by refering to no. 2016-230 "Method of Risk Assessment of Asbestos-Containing Buildings" from the Ministry of Environment. The risk of exposure to ACMs was rated by a score based on three categories(high, middle, low risk of asbestos exposure). Results: In this study, 30 of the 100 buildings and 36 of the 416 bulk samples(8.6%) were found to have had asbestos. Asbestos was detected at a high rate, in 18 out of 42, in buildings constructed in the 1990s and at the lowest rate(7 out of 44) for buildings constructed in the 2000s. As a result of the evaluation according to no. 2016-230 "Method of Risk Assessment of Asbestos-Containing Buildings" of the Ministry of Environment, the risk assessment level of two asbestos-containing building materials was found to be "Medium", and 28 buildings materials were found to be at the "Low" level. Conclusion: As asbestos is regulated by the government, it is required to conduct active management and implemention by introducing methods of risk assessment of asbestos exposure that are supported by data from various situations. In the case of buildings owned by individuals, building owners should be aware of the risk of exposure to asbestos.

• Korean Journal of Soil Science and Fertilizer
• /
• v.21 no.3
• /
• pp.289-295
• /
• 1988

An ordinary paddy variety Hwaseong and a high-yielding variety Samgang were taken under investigation to test the effect of top dressing of newly formulated three compound fertilizers on rice plants for at sprouting heads. The fertilizer formulate used were C. F. I (14-0-14; $NO_3-N$ and $NH_4-N$) and C. F. II (14-0-14; $NH_4-N$ only) and C. F. III (14-0-14 + OM 10%; $NO_3-N$ and $NH_4-N$). A field experiment was conducted on a plot of Gyuam series. The following results were obtained: 1. Effects of compound fertilizers at sprouting heads a. Hwaseong variety exhibited 5-10% yielding increases on the plots with application of 2nd compound fertilizer (I) and (II) compared to straight fertilizer of (I) and (III). Fertilization with 2nd and 3rd compound fertilizers gave the best result when they are done 15 days before heading. A yield increase of 3-5% was achieved when the fertilization was done 20 days before heading in the case of Samgang variety, but no beneficial effect was observed with an application 10 days before heading. b. Rate of barren grains was at the minimum in the compound fertilizer (II) plots of both Hwaseong and Samgang varieties. c. Content of $NO_3-N$ in soils and grain yield appeared to be positively correlated($r=0.618^*$) 2. Effects of heading fertilizers on artificially reduced conditions of soil a. No significant difference in Eh values were measured among reduced paddy soils. The compound fertilizer of (II) presented the best result in yield increases regardless of rice variety. b. Rate of barren grains in both varieties was observed at the minimum on the application of compound fertilizer of (II). c. No great difference of mineral contents was detected among plants from different treatments.

• Korean Journal of Food Science and Technology
• /
• v.7 no.3
• /
• pp.128-134
• /
• 1975

For development of long-term storage method of sweet-persimmons using polyethylene film bags, basic experiment was conducted with 30 boxes of sweet-persimmons in 1973 and the same experiment was extended for industrial application with 2,500 boxes of the persimmons in the cold storage of Jinyoung Sweet-persimmon Association in 1974. Investigation was made on change of the quality by storage period. At the same time, persimmons put in the cold storage test were shipped to market at different time in order to monitor consumer response and commercial feasibility. The followings are conclusion obtained from the result of this experiment. 1. Storage of sweet-persimmon, Buyu, produced in Jinyoung, Kimhae was possible for 1 month at $2^{\circ}C{\pm}1^{\circ}C$ cold storage. This storage period was extended to 4 months until the end of February in case that the fruits were hermetically sealed in P.E. film bags of 0.08 to 0.1 mm thickness. 2. During the storage period of sweet-persimmons packed in the film bags, the loss of weight due to evaporation was effectively prevented with use of the film of bag thicker than 0.04 mm. 3. The storage ability of 3-5 persimmons per small bag was somewhat superior to that of many persimmons packed in the large box of 15kg capacity. 4. The thicker the film of bags, the more $CO_2$ gas was accumulated inside, however, from 1 month after beginning of the storage the rate of $CO_2$ accumulation became very low maintaining the stabilized level of 5-6% at the plot of 0.06-0.08mm thick bags. 5. While the persimmons were in storage, decreased was the content of total sugars, total acids, and vitamin C, of which the phenomenon was remarkable especially with the fruits of non-packed plot. 6. The sweet-persimmons in the film bags subjected to cold storage when shipped to market in their intact condition were more beneficial than when they were shipped out in unpacked condition. The intact fruits packed in the P.E. film bags were able to keep their commercial value for 10days in the outdoor situation. 7. The sweet-persimmons that were packed in the film bags and put in the cold storage had maintained promissing marketability and the economic feasibility was acknowledged when the experimental practice was applied to industrial scale.

• Journal of Food Hygiene and Safety
• /
• v.29 no.4
• /
• pp.268-277
• /
• 2014

This study assessed microbiological hazards at postharvest stage of dropwort farms (A, B, C, D, E, F, G, H, I) located in 4 different areas in Korea. The samples were assessed for sanitary indication bacteria (total aerobic bacteria, coliform, and Escherichia coli) and pathogenic bacteria (Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus and Bacillus cereus). Total aerobic bacteria and coliform in 9 dropwort farms were detected at the levels of 0~7.00 and 0~4.25 log CFU/g, mL, of $100cm^2$. In particular, microbial contamination in worker's hand showed higher than cultivation environment factors. Escherichia coli was detected in several farms of soil, irrigation water, washing water and worker's hand and also, dropwort in these farms was contaminated with E. coli (positive reaction). In case of pathogenic bacteria, B. cereus was detected at the highest levels in soil. S. aureus was detected qualitatively from only one sample of dropwort washed by water. E. coli O157:H7 and L. monocytogenes were not detected. Although dropwort pass through 2 process (trimming and washing), the microbial contamination was not differ significantly before and after which indicates that current washing system was not effect on reduction of microorganism. From these results, the postharvest environment and workers have been considered as cross-contamination factors. Thus, processing equipments and personal hygiene should be managed to reduce the microbial contamination of dropwort. Accordingly management system such as good agricultural practices (GAP) criteria is needed for the safety of dropwort

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.28 no.2
• /
• pp.109-117
• /
• 2010

This study conducts a case analysis based on the Olympic Forest Park in Beijing, which is specially designed for the 2008 Beijing Olympic Games. The construction of the Olympic Forest Park not only comprises the design philosophy of city parks and forest parks, but also applies Chinese traditional design elements. This study, first, researches on the design concepts of city parks in the context of traditional landscape architecture elements from both physical and cultural perspectives. The author studies the related materials including the"General Introduction of the Beijing Olympic Forest Park Landscape Plan", and employs the approaches of site investigation and user survey and interview, to analyze the cognition and preference degree of the various traditional design elements displayed in the Olympic Forest Park. To quantize the survey data on the Olympic Forest Park, this study uses the spss(v17.0) software to run a frequency analysis and presents detailed demographic, frequencies and means analyses. The author then reaches the conclusion on the preference degree of the various Chinese traditional design elements in the Olympic Forest Park. According to the analysis result, the elements that appear with the highest frequencies are mountains and waters, traditional garden plants and artistic conception. The most favorable elements are in sequence traditional garden architecture, traditional garden philosophical thinking and artistic conception. The Olympic Forest Park in Beijing is constructed on the basis of multiple design elements, comprising Chinese traditional design elements and the historical axis. As an exemplification of contemporary city park that reflects the variation of age and development of society, the Olympic Forest Park offers the reference for the selection of traditional design elements in the future schemes of city parks. However, due to the difficulty in gathering materials about the Forest Park and the limitations on the location and time constrain of the survey, there exists lack of sufficiency that could be improved in the future.