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Topoclimatological interpretation of the daily air temperature minima at 17 locations crossing over Yangpyeong basin in 1986 spring (봄철 양평지역(楊平地域)의 지형(地形) 및 고도(高度)에 따른 일최저기온(日最低氣溫)의 분포(分布))

  • Kang, An-Seok;Yun, Jin-Il;Jung, Yeong-Sang;Tani, No Bureru
    • Korean Journal of Soil Science and Fertilizer
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    • v.19 no.4
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    • pp.339-344
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    • 1986
  • Frost damage which can reduce yields, impair fruit quality and cause loss of trees is closely related to the occurrence of daily minimum temperature. Horizontal distribution of air temperature minima can be characterized by conditions of radiational cooling and gravitational movement of cold air, which are influenced by the regional topographic features. Observations were made on the air temperature minima over Yangpyeong area, to delineate potential effects of topography on the temperature pattern during spring season. Two routes were selected for the observation. Liquid glass minimum thermometers were installed at 17 sites through the old peach orchards which had been closed due to the frequent freeze-frost hazards during the recent years. This route was 8.5km long and the highest point was 350m above mean sea level. The other route, which was 2.5km in distance, was run with a digital resistance thermometer during the hour just before sunrise. Observations were made both on a calm-clear day (April 30, 1986) and a windy-overcast day (May 1, 1986). The temperature on April 30 was in increasing trend with elevation but this was modified at near the riverside and the downtown area. An orchard lying on a hilltop showed the temperature $1^{\circ}C$ higher than near by lowland of which elevation was about 30m lower. The minimum temperature on the overcast day was little affected by terrestrial conditions but by the atmospheric lapse condition. The peach orchards severely damaged by cold air were found in the area where the lowest minimum temperature was observed. The results may be useful for selection of the proper orchard location to be developed in an area.

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DMFT Index, Periodontal Index and Oral Hygiene Status in Diabetic Patients (당뇨병 환자에서 우식경험영구치지수, 치주질환지수 및 구강위생 상태)

  • Lee, Kyung-Dong;Lee, Hee-Kyung
    • Journal of Yeungnam Medical Science
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    • v.22 no.1
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    • pp.62-71
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    • 2005
  • Background: This study examined the oral health condition of diabetic patients and evaluated the oral health behavior through a questionnaires survey. In addition, this study provide primary informations for developing a dental health program for diabetic patients. Materials and Methods: There were fifty patients with diabetes mellitus or glucose tolerance (controlled by a community health center at Dalsung-Gun in Daegu City and fifty nondiabetic age, gender and location matched control subjects. Data were collected by a direct oral examination and by questionnaires from 100 subjects in July, 2004. Results: The DMFT (Decay, Missing, Filling Teeth) mean values in diabetics were significantly higher than that in non-diabetics (p<0.05). The decay teeth index and Filling teeth index was similar in the two groups, but the mean Missing teeth index was significantly higher in the diabetics than in non-diabetics. The PI (Periodontal Index) mean values were significantly higher in the diabetics than in the non-diabetics (p<0.01). There was a significant difference between the diabetics and non diabetics aged in their 50s and 60s, but there was no difference with those aged in their 70s. The oral hygiene status was similar in the two groups. The average number of remaining teeth was significantly lower in the diabetics ($16.1{\pm}10.35$) than in the non-diabetics ($20.04{\pm}8.70$) (p<0.05). Conclusion: In the diabetic patients, the M component of the DMFT index was found to be higher than the controls. Diabetics lose their teeth mainly due to periodontal disease, which is supported by the increased PI mean values.

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Studies on Neck Blast Infection of Rice Plant (벼 이삭목도열병(病)의 감염(感染)에 관(關)한 연구(硏究))

  • Kim, Hong Gi;Park, Jong Seong
    • Korean Journal of Agricultural Science
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    • v.12 no.2
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    • pp.206-241
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    • 1985
  • Attempts to search infection period, infection speed in the tissue of neck blast of rice plant, location of inoculum source and effects of several conditions about the leaf sheath of rice plants for neck blast incidence have been made. 1. The most infectious period for neck blast incidence was the booting stage just before heading date, and most of necks have been infected during the booting stage and on heading date. But $Indica{\times}Japonica$ hybrid varieties had shown always high possibility for infection after booting stage. 2. Incubation period for neck blast of rice plants under natural conditions had rather a long period ranging from 10 to 22 days. Under artificial inoculation condition incubation period in the young panicle was shorter than in the old panicle. Panicles that emerged from the sheath of flag leaf had long incubation period, with a low infection rate and they also shown slow infection speed in the tissue. 3. Considering the incubation period of neck blast of rice plant, we assumed that the most effective application periods of chemicals are 5-10 days for immediate effective chemicals and 10-15 days for slow effective chemicals before heading. 4. Infiltration of conidia into the leaf sheath of rice plant carried out by saturation effect with water through the suture of the upper three leaves. The number of conidia observed in the leaf sheath during the booting stage were higher than those in the leaf sheath during other stages. Ligule had protected to infiltrate of conidia into the leaf sheath. 5. When conidia were infiltrated into the leaf sheath, the highest number of attached conidia was observed on the panicle base and panicle axis with hairs and degenerated panicle, which seemed to promote the infection of neck blast. 6. The lowest spore concentration for neck blast incidence was variable with rice varietal groups. $Indica{\times}Japonica$ hybrid varieties were infected easily compared to the Japonica type varieties, especially. The number of spores for neck blast incidence in $Indica{\times}Japonica$ hybrid varieties was less than 100 and disease index was higher also in $Indica{\times}Japonica$ hybrid than in Japonica type varieties. 7. Nitrogen content and silicate content were related with blast incidence in necks of rice plants in the different growing stage changed during growing period. Nitrogen content increased from booting stage to heading date and then decreased gradually as time passes. Silicate content increased from booting stage after heading with time. Change of these content promoted to increase neck blast infection. 8. Conidia moved to rice plant by ascending and desending dispersal and then attached on the rice plant. Conidia transfered horizontally was found very negligible. So we presumed that infection rate of neck blast was very low after emergence of panicle base from the leaf sheath. Also ascending air current by temperature difference between upper and lower side of rice plant seemed to increase the liberation of spores. 9. Conidial number of the blast fungus collected just before and after heading date was closely related with neck blast incidence. Lesions on three leaves from the top were closely related with neck blast incidence, because they had high potential for conidia formation of rice blast fungus and they were direct inoculum sources for neck blast. 10. The condition inside the leaf sheath was very favorable for the incidence of neck blast and the neck blast incidence in the leaf sheath increased as the level of fertilizer applied increased. Therefore, the infection rate of neck blast on the all panicle parts such as panicle base, panicle branches, spikelets, nodes, and internodes inside the leaf sheath didn't show differences due to varietal resistance or fertilizers applied. 11. Except for others among dominant species of fungi in the leaf sheath, only Gerlachia oryzae appeared to promote incidence of neck blast. It was assumed that days for heading of varieties were related with neck blast incidence.

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A study on Development Process of Fish Aquaculture in Japan - Case by Seabream Aquaculture - (일본 어류 양식업의 발전과정과 산지교체에 관한 연구 : 참돔양식업을 사례로)

  • 송정헌
    • The Journal of Fisheries Business Administration
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    • v.34 no.2
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    • pp.75-90
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    • 2003
  • When we think of fundamental problems of the aquaculture industry, there are several strict conditions, and consequently the aquaculture industry is forced to change. Fish aquaculture has a structural supply surplus in production, aggravation of fishing grounds, stagnant low price due to recent recession, and drastic change of distribution circumstances. It is requested for us to initiate discussion on such issue as “how fish aquaculture establishes its status in the coastal fishery\ulcorner, will fish aquaculture grow in the future\ulcorner, and if so “how it will be restructured\ulcorner” The above issues can be observed in the mariculture of yellow tail, sea scallop and eel. But there have not been studied concerning seabream even though the production is over 30% of the total production of fish aquaculture in resent and it occupied an important status in the fish aquaculture. The objectives of this study is to forecast the future movement of sea bream aquaculture. The first goal of the study is to contribute to managerial and economic studies on the aquaculture industry. The second goal is to identify the factors influencing the competition between production areas and to identify the mechanisms involved. This study will examine the competitive power in individual producing area, its behavior, and its compulsory factors based on case study. Producing areas will be categorized according to following parameters : distance to market and availability of transportation, natural environment, the time of formation of producing areas (leaderㆍfollower), major production items, scale of business and producing areas, degree of organization in production and sales. As a factor in shaping the production area of sea bream aquaculture, natural conditions especially the water temperature is very important. Sea bream shows more active feeding and faster growth in areas located where the water temperature does not go below 13∼14$^{\circ}C$ during the winter. Also fish aquaculture is constrained by the transporting distance. Aquacultured yellowtail is a mass-produced and a mass-distributed item. It is sold a unit of cage and transported by ship. On the other hand, sea bream is sold in small amount in markets and transported by truck; so, the transportation cost is higher than yellow tail. Aquacultured sea bream has different product characteristics due to transport distance. We need to study live fish and fresh fish markets separately. Live fish was the original product form of aquacultured sea bream. Transportation of live fish has more constraints than the transportation of fresh fish. Death rate and distance are highly correlated. In addition, loading capacity of live fish is less than fresh fish. In the case of a 10 ton truck, live fish can only be loaded up to 1.5 tons. But, fresh fish which can be placed in a box can be loaded up to 5 to 6 tons. Because of this characteristics, live fish requires closer location to consumption area than fresh fish. In the consumption markets, the size of fresh fish is mainly 0.8 to 2kg.Live fish usually goes through auction, and quality is graded. Main purchaser comes from many small-sized restaurants, so a relatively small farmer and distributer can sell it. Aquacultured sea bream has been transacted as a fresh fish in GMS ,since 1993 when the price plummeted. Economies of scale works in case of fresh fish. The characteristics of fresh fish is as follows : As a large scale demander, General Merchandise Stores are the main purchasers of sea bream and the size of the fish is around 1.3kg. It mainly goes through negotiation. Aquacultured sea bream has been established as a representative food in General Merchandise Stores. GMS require stable and mass supply, consistent size, and low price. And Distribution of fresh fish is undertook by the large scale distributers, which can satisfy requirements of GMS. The market share in Tokyo Central Wholesale Market shows Mie Pref. is dominating in live fish. And Ehime Pref. is dominating in fresh fish. Ehime Pref. showed remarkable growth in 1990s. At present, the dealings of live fish is decreasing. However, the dealings of fresh fish is increasing in Tokyo Central Wholesale Market. The price of live fish is decreasing more than one of fresh fish. Even though Ehime Pref. has an ideal natural environment for sea bream aquaculture, its entry into sea bream aquaculture was late, because it was located at a further distance to consumers than the competing producing areas. However, Ehime Pref. became the number one producing areas through the sales of fresh fish in the 1990s. The production volume is almost 3 times the production volume of Mie Pref. which is the number two production area. More conversion from yellow tail aquaculture to sea bream aquaculture is taking place in Ehime Pref., because Kagosima Pref. has a better natural environment for yellow tail aquaculture. Transportation is worse than Mie Pref., but this region as a far-flung producing area makes up by increasing the business scale. Ehime Pref. increases the market share for fresh fish by creating demand from GMS. Ehime Pref. has developed market strategies such as a quick return at a small profit, a stable and mass supply and standardization in size. Ehime Pref. increases the market power by the capital of a large scale commission agent. Secondly Mie Pref. is close to markets and composed of small scale farmers. Mie Pref. switched to sea bream aquaculture early, because of the price decrease in aquacultured yellou tail and natural environmental problems. Mie Pref. had not changed until 1993 when the price of the sea bream plummeted. Because it had better natural environment and transportation. Mie Pref. has a suitable water temperature range required for sea bream aquaculture. However, the price of live sea bream continued to decline due to excessive production and economic recession. As a consequence, small scale farmers are faced with a market price below the average production cost in 1993. In such kind of situation, the small-sized and inefficient manager in Mie Pref. was obliged to withdraw from sea bream aquaculture. Kumamoto Pref. is located further from market sites and has an unsuitable nature environmental condition required for sea bream aquaculture. Although Kumamoto Pref. is trying to convert to the puffer fish aquaculture which requires different rearing techniques, aquaculture technique for puffer fish is not established yet.

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The Present Status and the Preservation Method of the Rice Terrace as Scenic Sites Resources in Northeast Asia (동북아시아 계단식 논의 명승지정 현황 및 보전방안)

  • Youn, Kyung-Sook;Lee, Chang-Hun;Kim, Hyung-Dae;Seo, Woo-Hyun;Lee, Jae-Keun
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.29 no.4
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    • pp.111-123
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    • 2011
  • This study aims to present the basic materials, which lead us to preserve the Korea Rice Terrace as scenic sites resources and study it continuously, through researching about the present status and the preservation method of the Rice Terrace in Korea, China and Japan. The results of this study are as follows. First, The Rice Terrace has a traditional agricultural technique which minimizing the damage of the scenic view while cultivating the slope. And also, it has the value of one of the Korea unique traditional scenic views. However, The no cultivation land or disappearing desert land of rice terrace were increasing by the disadvantage of operation in land cultivation. Therefore, The Government must need preparing the base of scene resources excavation by executed the established of Korea Rice Terrace Database for preserving of Korea traditional scene. however it is getting to disappearance. And also, The High valued of Rice Terrace by cultural and scenic view which is must managed by designation of scenic sites or monument. Second, The internal and external reference book researched and analyzed results are as followings for understanding about Korea Rice Terrace feature. First of all, The Rice Terrace's dictionary meaning is just difference by each nations. However, Generally speaking that It means the terraced land by cultivated of sloped land. The Rice Terrace has cross relation with mountain valley and piedmont slope cultivation in location of condition. It occurred era is before approximately estimated from 3000 of years until 6000 of years. It can divide two type by topography shape those are slope and valley type. However, The natural element of forest has very big position in this part. But, The Rice Terrace is just managed and designated by the scenic sites with the Cultural Properties Protection Law. It must needs more binding force and effectiveness for the Rice Terrace scenic view plan establishment by scenic laws and farming and fishing village laws etc. I think that it must need the Rice Terrace related law establishment as soon as possible for efficient preservation and management of the Rice Terrace. Third, The Rice Terrace were researched and analyzed results are as followings those were executed at the Korea, China and Japan. The Korea and Japan have good Rice Terrace Characteristic. And also, The high valued scenic sites area were good managed by the Cultural Properties Protection Law as well as the superior scenic valued Rice Terrace in China. Those are also managed by designated scenic sites for protection and preservation positively. Those were managed by each autonomous district management Department. The each nation's related laws of Rice Terrace protection were just little bit different. However, The basic purpose is same. for example, it based on superior scenic view preservation and protection. Especially, The Japan's Cultural Properties Law and Scenic law linkage, and China Autonomous district legislation and effectiveness. The Korea Government must need above elements for Korea Rice Terrace culture and scenic view preservation. Fourth, We need inducing the owner system and the policy of Rice Terrace preservation promotion association for efficient preservation of Rice Terrace in japan. The owner system in japan gives the owner of the land a permission to rent the land to Rice Terrace preservation promotion association and the local government. In this system the village would be revitalized by commons in the way of the management of the terraces, beautifying the area around the terraces and etc. And also, Making the each village management operating system for Rice Terrace management through educating civilization. The civilization could receive quick help from a consultative body comprised of experts such as representatives of Cultural Heritage Administration and professors. And it is in a hurry to solve the problem of revitalization of the region by exchange between cities and the village.

Efficient Topic Modeling by Mapping Global and Local Topics (전역 토픽의 지역 매핑을 통한 효율적 토픽 모델링 방안)

  • Choi, Hochang;Kim, Namgyu
    • Journal of Intelligence and Information Systems
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    • v.23 no.3
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    • pp.69-94
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    • 2017
  • Recently, increase of demand for big data analysis has been driving the vigorous development of related technologies and tools. In addition, development of IT and increased penetration rate of smart devices are producing a large amount of data. According to this phenomenon, data analysis technology is rapidly becoming popular. Also, attempts to acquire insights through data analysis have been continuously increasing. It means that the big data analysis will be more important in various industries for the foreseeable future. Big data analysis is generally performed by a small number of experts and delivered to each demander of analysis. However, increase of interest about big data analysis arouses activation of computer programming education and development of many programs for data analysis. Accordingly, the entry barriers of big data analysis are gradually lowering and data analysis technology being spread out. As the result, big data analysis is expected to be performed by demanders of analysis themselves. Along with this, interest about various unstructured data is continually increasing. Especially, a lot of attention is focused on using text data. Emergence of new platforms and techniques using the web bring about mass production of text data and active attempt to analyze text data. Furthermore, result of text analysis has been utilized in various fields. Text mining is a concept that embraces various theories and techniques for text analysis. Many text mining techniques are utilized in this field for various research purposes, topic modeling is one of the most widely used and studied. Topic modeling is a technique that extracts the major issues from a lot of documents, identifies the documents that correspond to each issue and provides identified documents as a cluster. It is evaluated as a very useful technique in that reflect the semantic elements of the document. Traditional topic modeling is based on the distribution of key terms across the entire document. Thus, it is essential to analyze the entire document at once to identify topic of each document. This condition causes a long time in analysis process when topic modeling is applied to a lot of documents. In addition, it has a scalability problem that is an exponential increase in the processing time with the increase of analysis objects. This problem is particularly noticeable when the documents are distributed across multiple systems or regions. To overcome these problems, divide and conquer approach can be applied to topic modeling. It means dividing a large number of documents into sub-units and deriving topics through repetition of topic modeling to each unit. This method can be used for topic modeling on a large number of documents with limited system resources, and can improve processing speed of topic modeling. It also can significantly reduce analysis time and cost through ability to analyze documents in each location or place without combining analysis object documents. However, despite many advantages, this method has two major problems. First, the relationship between local topics derived from each unit and global topics derived from entire document is unclear. It means that in each document, local topics can be identified, but global topics cannot be identified. Second, a method for measuring the accuracy of the proposed methodology should be established. That is to say, assuming that global topic is ideal answer, the difference in a local topic on a global topic needs to be measured. By those difficulties, the study in this method is not performed sufficiently, compare with other studies dealing with topic modeling. In this paper, we propose a topic modeling approach to solve the above two problems. First of all, we divide the entire document cluster(Global set) into sub-clusters(Local set), and generate the reduced entire document cluster(RGS, Reduced global set) that consist of delegated documents extracted from each local set. We try to solve the first problem by mapping RGS topics and local topics. Along with this, we verify the accuracy of the proposed methodology by detecting documents, whether to be discerned as the same topic at result of global and local set. Using 24,000 news articles, we conduct experiments to evaluate practical applicability of the proposed methodology. In addition, through additional experiment, we confirmed that the proposed methodology can provide similar results to the entire topic modeling. We also proposed a reasonable method for comparing the result of both methods.

Research on the Relation between Musculoskeletal symptoms and Diagnosis using Moire Topography among Workers at an Automobile Manufacturing Plant (자동차회사 근로자를 대상으로 한 근골격계 자각증상과 moire 영상 진단과의 관계 연구)

  • Chun Eun-Joo;Lee Young-Gil;Jahng Doo-Sub;Lee Ki-Nam;Song Yung-Sun
    • Journal of Society of Preventive Korean Medicine
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    • v.5 no.2
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    • pp.69-92
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    • 2001
  • The purposes of this study were to offer foundation making more certain standards of musculoskeletal disorder diagnosis, We researched musculoskeletal symptoms degrees, frequencies, and cares and then examined relation between musculoskeletal symptoms and diagnosis of musculoskeletal conditions using moire topography among workers at an automobile manufacturing plant. Therefore we propose the possibility of moire topography as diagnosing utilities of musculoskeletal disorders. Methods: This study was to examine the general characteristics, complaints of musculoskeletal symptoms, and work-related musculoskeletal disorder rates of cervicobrachial and lumbar area by survey among 435 workers at an automobile manufacturing plant and then to show each frequency and percentage, In the diagnosis using moire topography, we studied pain control necessity of cervicobrachial and lumbar area, 435 subjects were classified by 5 levels: A(no symptoms), B(need management), C(need treatment) and then more divided by B1(light symptoms)/B2(heavy symptoms), C1(light symptoms)/C2(heavy symptoms), And musculoskeletal areas were divided by 2 parts, cervicobrachial area(neck, shoulder, arm&elbow, and wrist&hand) and lumbar area, Then, frequency and percentage of each musculoskeletal areas(cervicobrachial and lumbar area) were appeared. At last, Pearson's chi-square test analysis was utilized to observe the relation between diagnosis using moire topography and general characteristics and the relation between diagnosis using moire topography and work-related complaint of musculoskeletal symptoms of cervicobrachial and lumbar area, Results: The subjects employed for this research were categorized into; by gender, all of them were males(l00%): by age, under 35 years 12 %, 36-40 years 56.3%, 41-45 years 26.3 %, and above 46 years 5.3% with 36-40 years accounting for most of it. By living location, owned houses represented 69.7%, rented houses 23.4%, monthly-rented 1.6%, the others 5.3%; by education, middle school and lower represented 3.0%, high school 89.4%, and junior college and higher 7.6% with high school occupying most of the group. By marital status, married represented 95.2%, unmarried 4.1%, and the others 0.7% with most of them married; by alcohol, drinking represented 81.8% and non-drinking 18.2%; by smoking status, smoking represented 53.6%, non-smoking 46.4% with no big difference between them. By working time(hours/week), below 50 represented 26.9%, 50-60 67.6%, above 60 5.5%; by working time(hours/day), below 9 represented 21.6%, 10-12 73.1%, above 13 5.3%; by job tenure(years), below 10 represented 25.1%, 11-15 54.3%, 16-20 15.2%, above 21 5.5%. By personal income per year, below 30 million won represented 11.0%, 30-40 84.8%, above 40 4.1%; by sleeping hours, below 6 hours represented 26.7%, 7-8 hours 69.9%, above 9 hours 3.4%. Complaint rates of musculoskeletal symptoms and work-related musculoskeletal disorder rates were 63.9% and 54.9% with shoulder area occupying most of both them. By pain degree of musculoskeletal symptoms, shoulder area represented $2.73{\pm}0.84$, lumbar area $2.66{\pm}0.86$, wrist and hand area $2.59{\pm}0.86$, neck area $2.55{\pm}0.74$, and arm and elbow area $2.48{\pm}0.71$. By cares about musculoskeletal symptoms, taking medication or care represented 34.4%-46.7%, absence or leave 15.4%-28.7%, and job transfer 6.3%-11.5%. So experienced cases more than one thing among cares about musculoskeletal symptoms represented 39.6%-54%. In the diagnosis using moire topography, pain control necessity of cervicobrachial area was shown below; A(no symptoms) 20.7%, B1(need management/light symptoms) 64.6%, B2(need management/heavy symptoms) 11.5%, C1(need treatment/light symptoms) 3.0%, C2(need treatment/heavy symptoms) 0.2%. By lumbar area, A(no symptoms) 8.7%, B1(need management/light symptoms) 52.2%, B2(need management/heavy symptoms) 30.3%, C1(need treatment/light symptoms) 8.7%, C2(need treatment/heavy symptoms) was none. In the relation between pain control necessity and general characteristics, age(P=0.013), education(P=0.000), and job tenure(P=0.012) with pain control necessity showed differences with significance. The relation between pain control necessity and complaint of musculoskeletal symptoms of cervicobrachial and lumbar area showed no difference with significance; in cervicobrachial area represented P=0.708, lumbar area P=0.318 Conclusions: This study for musculoskeletal symptoms on workers at automobile manufacturing plant showed that complaint rates of musculoskeletal symptoms for cervicobrachial and lumbar area were so high, 63.9%. But Pearson's chi-square test analysis was utilized to study the relation between musculoskeletal symptoms and the diagnosis using moire topography, showed no differences with significance. They have no differences with significance, but the prevalence rates of diagnosis using moire topography for cervicobrachial and lumbar area were more higher than complaint rates of musculoskeletal symptoms; complaint rates of musculoskeletal symptoms were 52.4%, 34.5% and the diagnosis using moire topography were 79.3%, 91.3% for cervicobrachial and lumbar area. The results of this study indicate that the diagnosis using moire topography can find weak musculoskeletal disorders that an individual can not feel, not be judged work-related musculoskeletal disease. Therefore, this study has an important meaning that diagnosis using moire topography can predict and control own physical condition complete musculoskeletal disorders beforehand, since oriental medicine theory considers that prevention is important.

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DC Resistivity method to image the underground structure beneath river or lake bottom (하저 지반특성 규명을 위한 전기비저항 탐사)

  • Kim Jung-Ho;Yi Myeong-Jong;Song Yoonho;Cho Seong-Jun;Lee Seong-Kon;Son Jeongsul
    • 한국지구물리탐사학회:학술대회논문집
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    • 2002.09a
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    • pp.139-162
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    • 2002
  • Since weak zones or geological lineaments are likely to be eroded, weak zones may develop beneath rivers, and a careful evaluation of ground condition is important to construct structures passing through a river. Dc resistivity surveys, however, have seldomly applied to the investigation of water-covered area, possibly because of difficulties in data aquisition and interpretation. The data aquisition having high quality may be the most important factor, and is more difficult than that in land survey, due to the water layer overlying the underground structure to be imaged. Through the numerical modeling and the analysis of case histories, we studied the method of resistivity survey at the water-covered area, starting from the characteristics of measured data, via data acquisition method, to the interpretation method. We unfolded our discussion according to the installed locations of electrodes, ie., floating them on the water surface, and installing at the water bottom, since the methods of data acquisition and interpretation vary depending on the electrode location. Through this study, we could confirm that the dc resistivity method can provide the fairly reasonable subsurface images. It was also shown that installing electrodes at the water bottom can give the subsurface image with much higher resolution than floating them on the water surface. Since the data acquired at the water-covered area have much lower sensitivity to the underground structure than those at the land, and can be contaminated by the higher noise, such as streaming potential, it would be very important to select the acquisition method and electrode array being able to provide the higher signal-to-noise ratio data as well as the high resolving power. The method installing electrodes at the water bottom is suitable to the detailed survey because of much higher resolving power, whereas the method floating them, especially streamer dc resistivity survey, is to the reconnaissance survey owing of very high speed of field work.

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Evaluation of Image Quality Based on Time of Flight in PET/CT (PET/CT에서 재구성 프로그램의 성능 평가)

  • Lim, Jung Jin;Yoon, Seok Hwan;Kim, Jong Pil;Nam Koong, Sik;Shin, Seong Hwa;Yoon, Sang Hyeok;Kim, Yeong Seok;Lee, Hyeong Jin;Lee, Hong Jae;Kim, Jin Eui;Woo, Jae Ryong
    • The Korean Journal of Nuclear Medicine Technology
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    • v.16 no.2
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    • pp.110-114
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    • 2012
  • Purpose : PET/CT is widely used for early checking up of cancer and following up of pre and post operation. Image reconstruction method is advanced with mechanical function. We want to evaluate image quality of each reconstruction program based on time of flight (TOF). Materials and Methods : After acquiring phantom images during 2 minutes with Gemini TF (Philips, USA), Biograph mCT (Siemens, USA) and Discovery 690 (GE, USA), we reconstructed image applied to Astonish TF (Philips, USA), ultraHD PET (Siemens, USA), Sharp IR (GE, USA) and not applied. inside of Flangeless Esser PET phantom (Data Spectrum corp., USA) was filled with $^{18}F$-FDG 1.11 kBq/ml (30 Ci/ml) and 4 hot inserts (8. 12. 16. 25 mm) were filled with 8.88 kBq/ml (240 ${\mu}Ci/ml$) the ratio of background activity and hot inserts activity was 1 : 8. Inside of triple line phantom (Data Spectrum corp., USA) was filled with $^{18}F$-FDG 37 MBq/ml (1 mCi). Three of lines were filled with 0.37 MBq (100 ${\mu}Ci$). Contrast ratio and background variability were acquired from reconstruction image used Flangeless Esser PET phantom and resolution was acquired from reconstruction image used triple line phantom. Results : The contrast ratio of image which was not applied to Astonish TF was 8.69, 12.28, 19.31, 25.80% in phantom lid of which size was 8, 12, 16, 25 mm and it which was applied to Astonish TF was 6.24, 13.24, 19.55, 27.60%. It which was not applied to ultraHD PET was 4.94, 12.68, 22.09, 30.14%, it which was applied to ultraHD PET was 4.76, 13.23, 23.72, 31.65%. It which was not applied to SharpIR was 13.18, 17.44, 28.76, 34.67%, it which was applied to SharpIR was 13.15, 18.32, 30.33, 35.73%. The background variability of image which was not applied to Astonish TF was 5.51, 5.42, 7.13, 6.28%. it which was applied to Astonish TF was 7.81, 7.94, 6.40 6.28%. It which was not applied to ultraHD PET was 6.46, 6.63, 5.33, 5.21%, it which was applied to ultraHD PET was 6.08, 6.08, 4.45, 4.58%. It which was not applied to SharpIR was 5.93, 4.82, 4.45, 5.09%, it which was applied to SharpIR was 4.80, 3.92, 3.63, 4.50%. The resolution of phantom line of which location was upper, center, right, which was not applied to Astonish TF was 10.77, 11.54, 9.34 mm it which was applied to Astonish TF was 9.54, 8.90, 8.88 mm. It which was not applied to ultraHD PET was 7.84, 6.95, 8.32 mm, it which was applied to ultraHD PET was 7.51, 6.66, 8.27 mm. It which was not applied to SharpIR was 9.35, 8.69, 8.99, it which was applied to SharpIR was 9.88, 9.18, 9.00 mm. Conclusion : Image quality was advanced generally while reconstruction program which is based on time of flight was used. Futhermore difference of result compared each manufacture reconstruction program showed up, however this is caused by specification of instrument of each manufacture and difference of reconstruction algorithm. Therefore we need further examination to find out appropriate reconstruction condition while using reconstruction program used for advance of image quality.

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The Variation of Natural Population of Pinus densiflora S. et Z. in Korea (III) -Genetic Variation of the Progeny Originated from Mt. Chu-wang, An-Myon Island and Mt. O-Dae Populations- (소나무 천연집단(天然集團)의 변이(變異)에 관(關)한 연구(硏究)(III) -주왕산(周王山), 안면도(安眠島), 오대산(五臺山) 소나무집단(集團)의 차대(次代)의 유전변이(遺傳變異)-)

  • Yim, Kyong Bin;Kwon, Ki Won
    • Journal of Korean Society of Forest Science
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    • v.32 no.1
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    • pp.36-63
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    • 1976
  • The purpose of this study is to elucidate the genetic variation of the natural forest of Pinus densiflora. Three natural populations of the species, which are considered to be superior quality phenotypically, were selected. The locations and conditions of the populations are shown in table 1 and 2. The morphological traits of tree and needle and some other characteristics were presented already in our first report of this series in which population and family differences according to observed characteristics were statistically analyzed. Twenty trees were sampled from each populations, i.e., 60 trees in total. During the autumn of 1974, matured cones were collected from each tree and open-pollinated seeds were extracted in laboratory. Immediately after cone collection, in closed condition, the morphological characteristics were measured. Seed and seed-wing dimensions were also studied. In the spring of 1975, the seeds were sown in the experimental tree nursery located in Suweon. And in the April of 1976, the 1-0 seedlings were transplanted according to the predetermined experimental design, randomized block design with three replications. Because of cone setting condition. the number of family from which progenies were raised by populations were not equal. The numbers of family were 20 in population 1. 18 in population 2 and 15 in population 3. Then, each randomized block contained seedlings of 53 families from 3 populations. The present paper is mainly concerned with the variation of some characteristics of cone, seed, needle, growth performance of seedlings, and chlorophyll and monoterpene compositions of needles. The results obtained are summerized as follows. 1. The meteorological data obtained by averaging the records of 30 year period, observed from the nearest station to each location of populations, are shown in Fig. 3, 4, and 5. The distributional pattern of monthly precipitation are quite similar among locations. However, the precipitation density on population 2, Seosan area, during growing season is lower as compared to the other two populations. Population 1. Cheong-song area, and population 3, Pyong-chang area, are located in inland, but population 2 in the western seacoast. The differences on the average monthly air temperatures and the average monthly lowest temperatures among populations can hardly be found. 2. Available information on the each mother trees (families) studied, such as age, stem height, diameter at breast height, clear-bole-length, crown conditions and others are shown in table 6,7, and 8. 3. The measurements of fresh cone weight, length and the widest diameter of cone are given in Tab]e 9. All these traits arc concerned with the highly significant population differences and family differences within population. And the population difference was also found in the cone-index, that is, length-diameter ratio. 4. Seed-wing length and seed-wing width showed the population differences, and the family differences were also found in both characteristics. Not discussed in this paper, however, seed-wing colours and their shapes indicate the specificity which is inherent to individual trees as shown in photo 3 on page 50. The colour and shape are fully the expression of genetic make up of mother tree. The little variations on these traits are resulted from this reason. The significant differences among populations and among families were found in those characteristics, such as 1000-seed weight, seed length, seed width, and seed thickness as shown in table 11. As to all these dimensions, the values arc always larger in population 1 which is younger in age than that of the other two. The population differences evaluated by cone, seed and seed-wing sizes could partly be attributed to the growth vigorousity. 5. The values of correlation between the characteristics of cone and seed are presented in table 12. As shown, the positive correlations between cone diameter and seed-wing width were calculated in all populations studied. The correlation between seed-wing length and seed length was significantly positive in population 1 and 3 but not in population 2, that is, the r-value is so small as 0.002. in the latter. The correlation between cone length and seed-wing length was highly significant in population 1, but not in population 2. 6. Differences among progenies in growth performances, such as 1-0 and 1-1 seedling height and root collar diameter were highly singificant among populations as well as families within population(Table 13.) 7. The heritability values in narrow sense of population characteristics were estimated on the basis of variance components. The values based on seedling height at each age stage of 1-1 and 1-0 ranged from 0.146 to 0.288 and the values of root collar diameter from 0.060 to 0.130. (Table 14). These heritability values varied according to characteristics and seedling ages. Here what must be stated is that, for calculation of heritability values, the variance values of population was divided by the variance value of environment (error) and family and population. The present authors want to add the heritability values based on family level in the coming report. It might be considered that if the tree age is increased in furture, the heritability value is supposed to be altered or lowered. Examining the heritability values studied previously by many authors, in pine group at age of 7 to 15, the values of height growth ranged from 0.2 to 0.4 in general. The values we obtained are further below than these. 8. The correlation between seedling growth and seed characteristics were examined and the values resulted are shown in table 16. Contrary to our hypothetical premise of positive correlation between 1-0 seedling height and seed weight, non-significance on it was found. However, 1-0 seedling height correlated positively with seed length. And significant correlations between 1-0 and 1-1 seedling height are calculated. 9. The numbers of stomata row calculated separately by abaxial and adaxial side showed highly significant differences among populations, but not in serration density. On serration density, the differences among families within population were highly significant. (Table 17) A fact must be noted is that the correlation between stomata row on abaxial side and adaxial side was highly significant in all populations. Non-significances of correlation coefficient between progenies and parents regarding to stomata row on abaxial side were shown in all populations studied.(Table 18). 10. The contents of chhlorophyll b of the needle were a little more than that of chlorophyll a irrespective of the populations examined. The differences of chlorophyll a, b and a plus b contents were highly significant but not among families within populations as shown in table 20. The contents of chlorophyll a and b are presented by individual trees of each populations in table 21. 11. The occurrence of monoterpene components was examined by gas liquid chromatography (Shimazu, GC-1C type) to evaluate the population difference. There are some papers reporting the chemical geography of pines basing upon monoterpene composition. The number of populations studied here is not enough to state this problem. The kinds of monoterpene observed in needle were ${\alpha}$-pinene, camphene, ${\beta}$-pinene, myrcene, limonene, ${\beta}$-phellandrene and terpinolene plus two unknowns. In analysis of monoterpene composition, the number of sample trees varied with population, I.e., 18 families for population 1, 15 for population 2 and 11 for population3. (Table 22, 23 and 24). The histograms(Fig. 6) of 7 components of monoterpene by population show noticeably higher percentages of ${\alpha}$-pinene irrespective of population and ${\beta}$-phellandrene in the next order. The minor Pinus densiflora monoterpene composition of camphene, myrcene, limonene and terpinolene made up less than 10 percent of the portion in general. The average coefficients of variation of ${\alpha}$-pinene and ${\beta}$-phellandrene were 11 percent. On the contrary to this, the average coefficients of variation of camphene, limonene and terpinolene varied from 20 to 30 percent. And the significant differences between populaiton were observed only in myrcene and ${\beta}$-phellandrene. (Table 25).

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