• Korean journal of applied entomology
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• v.55 no.4
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• pp.483-487
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• 2016

The damage of citrus fruits caused by Scirtothrips dorsalis Hood has being increased in Jeju, Korea. The seasonal abundance of S. dorsalis and its injury symptoms in citrus orchards have been studied since the endemic outbreak in Jeju, but studies for the occurrence pattern of S. dorsalis in citrus orchards influenced by adjacent primary hosts have not been fully conducted yet. We selected kiwi- and mango-citrus adjacent orchards to study the migration pattern of S. dorsalis toward to citrus orchards. Yellow-colored sticky traps were used for monitoring the seasonal abundance of S. dorsalis and their migration pattern in two orchards. In citrus orchards, also, we placed sticky traps at 0, 5, 10, 15 and 20 m apart from the border of kiwi orchard, and 0, 7 and 20 m apart from the border of mango orchard. The seasonal occurrence pattern of S. dorsalis caught on sticky traps were similar between two adjacent orchards. However, the abundances in kiwi or mango orchard was much higher than those of citrus. Also, it was found that densities, distribution and damage of S. dorsalis in citrus orchards depend highly on the distance from the border of kiwi and mango orchards. This result suggested that the primary hosts such as kiwi and mango plants influence the occurrence of S. dorsalis in adjacent citrus orchards. And this information may provide a basic direction for establishing the management strategy of S. dorsalis in citrus orchards.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.3
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• pp.257-266
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• 2007

The research on red tide is generally in progress through field work, such as the naked eye and sampling. It was difficult to forecast exactly the course, from appearance of red tide to disappearance. with the established ways of investigation and analysis. Accordingly it is need to analyze environmental factors in time and space, the appearance of red tide and the path of its migration by more objective and scientific methods. In this study, GIS is applied to analyse the space character of red tide and the interpolation of IDW(Inverse Distance Weight) is applied to assume the density distribution of red tide after gather data by using Arc/Info. After IDW interpolation, the sea area occurred over 1,000 cells/ml of red tide density is extracted with CON and SUM Function of Grid Module, and the density of the sea area is accumulated daily. As a result of this study, the distribution condition of red tide is found timely and spacially by applying GIS to the sea area of red tide, the results indicated that the spatial density and the cumulative frequency about the origin of red tide using GIS, the sea area demonstrated that the maximum density and the maximum frequency varied significantly over the Nammyun of Namhae-Is. with the maximum frequency being 49 times. accordingly if data about the areas of red tide will occur from the present are accumulated, the shifting route of red tide occurrence and extinction can be predicted.

• Research in Plant Disease
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• v.24 no.3
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• pp.202-212
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• 2018

Major viruses infecting rice are transmitted by planthoppers such as small brown planthopper (SBPH), brown planthopper (BPH) and white-backed planthopper (WBPH). In this study, we investigated planthoppers captured during 2015 to 2017 by a smart sky net trap (SSNT) system installed in 40 areas in Korea, which is an automatic, rapid and real-time insect surveillance system. The average rates of captured migration plnathoppers was 27.5%, 17.2%, 15.3% and 10.9% in Chungcheongnamdo, Jeollanamdo, Jeollabukdo and Gyeonggido, orderly. The highly migrated month was July for SBPH, July to August for WBPH and August for BPH. To investigate the viruliferous rates of planthoppers of rice during 2015 to 2017, we performed RT-PCR using specific primers for each rice virus. RBSDV was detected from 0.4% in SBPH, while no viruses were detected in BPH and SBPH. Rice planthoppers exist all around in Asia. They can move long distance by wind from southern countries to Korea. Monitoring the migration of rice planthoppers and their viruliferous rates is important to prevent the outbreaks of rice virus diseases.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.452-460
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• 2017

Rice fields are important stopover sites for the conservation of shorebirds during long-distance migration. These fields serve as food sources providing energy for the next leg of the journey. Shorebirds are able to change their preferred food source at stopover sites. However, the type and distribution of food resources remain unknown for the shorebirds in the Republic of Korea. Therefore, we studied the type and distribution pattern of food resource (macroinvertebrates, remaining rice, and other seeds) for shorebirds in the rice fields. We have identified potential and actual food sources for shorebirds in the rice fields. The potential food sources were collected by using a core-sampling method and the actual food source was ascertained by observational analysis. As a result, a total 19 species of benthic macroinvertebrates in 15 families were recorded as potential food sources. A total of 9 families in 9 orders of benthic macroinvertebrates known to be actual food sources were also recorded during the study period, including loaches, and a tuber of sea club rush. Also, the distribution of the food source depended on soil conditions generated by cultivation such as plowing, harrowing, and the use of pesticides. In the present study, we identified the type and distribution of food sources for shorebirds. This information can be used as essential primary baseline data for conservation of shorebirds using the rice fields of the Republic of Korea.

• Korean Journal of Environment and Ecology
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• v.30 no.2
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• pp.146-154
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• 2016

In this study, understanding the habitats on spot-billed duck that wintering-breed in the korea, which using the GPS-Mobile based Telemtry (WT-200), I tried to take advantage as the basic data of the protection and management of the habitats of the waterbirds of Korea. Study area is Gyeonggi-do Bokhacheon, Chonmichon, Chungcheongnam-do Gokugyochon, Chungcheongbuk-do Byeongcheoncheon, Jeollabuk-do Mangyunggang, which Five rivers and Jeju Island reservoir, I have attached the tracking of the location(WT -200) to the twenty-five spot-billed ducks. among twenty five ducks, twelve ducks moved to overseas countries, the arrival site was China, North Korea, Russia. Moving average distance was 683km, the largest distance was 1,238km. The average northbound starting date was April 26. The average daily movement distance of thirteen ducks remaining in the domestic country is $1.0{\pm}0.89km$, maximum travel distance was 23.8km. The average daily movement distance of wintering prior to average going north dating is a 0.9km, is the largest 14.6km, the breeding season is an average 1.3km, maximum was 14.4km. Spot-billed duck used the rivers in domestic country most frequently, following was rice field, a filed, reservoir. It used the river most frequently during the wintering period, in the breeding season it used paddy paddies most frequently. While wintering, during the day and night's utilization rate was the highest in the river, but utilization rate was incleased on filed, paddy filed at night. During breeding season, daytime and night's utilization rate was the highest but, utilization rate was increased on river and utilization rate was decreased on river. In accordance with time change, spot-billed duck showed different tendency in paddy fields, and they utilized the filed adjacent to rivers mostly.

• Journal of Korean Society of Transportation
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• v.26 no.3
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• pp.67-74
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• 2008

Even though the efficiency of a point based black spot improvement project has been low, none of solid methodology, which is based on section not point, and is considered as one of the promising substitute, has not been come up with yet. Thus, this research aims at proposing the adequate length of a hazardous section and a method to set segment length over which the project needs to be performed on rural highways by analyzing the distances from project-conducted sites to new black spots in the following year and distances between project needed but not conducted sites and new black spots in the following year. According to the analysis, the probability of being a new black spot near the project conducted intersection is higher than that of a non-conducted intersection within 2km, however, no strong relationships between project types and distance distribution have been found. Based on those findings, a method to determine the target segment including adjacent black spots within 2 kilometers-range was proposed.

• Journal of the Korean Geographical Society
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• v.30 no.3
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• pp.311-323
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• 1995

This study attempts to examine the location and district of elementary schools at Chongro-gu. For the convenience of the analysis, the data are analysed with the methods of GIS network model. For the purpose data was collected from Statistical Yearbook of Education in 1994 and Census of Housing and Population in 1990. Results may be summarized as follows. First of all, spatial pattern of elementary school at Chongro-gu shows outward diffusion because of problems, rising of land value, and out-migration of population in the area. Secondly, for the analysis of locational situation this paper uses the data such as population of 5-9 age, the number of housing, accessibility, and land value. The location of elementary school is ciassified into 4 types; the best area, better area, worse area, the worst area. The best area is Pyongchana-dong, Buam-dong, and Ewha-dong and the worst area is Chongro 1ga-dona, Chonaro 2ga-dong and Sechongno-dong. Thirdly, the alternative plans of school district are presented for the maximum equity and efficience, and security of school attendantes. The former emphasizes the minimization of commuting distance, the later emphasizes the minimization of the an comfortable facilities such as main streets in school district. Present school district which is based upon administrative dong should be changed to roadbased school district.

• Journal of Korean Neurosurgical Society
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• v.42 no.5
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• pp.367-370
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• 2007

Objective : There are numerous reports on the primary stabilizing effects of the different cervical cages for cervical radiculopathy. But, little is known about the subsidence which may be clinical problem postoperatively. The goal of this study is to evaluate subsidence of cage and investigate the correlation between radiologic subsidence and clinical outcome. Methods : To assess possible subsidence, the authors investigated clinical and radiological results of the one-hundred patients who underwent anterior cervical fusion by using $AMSLU^{TM}$ cage during the period between January 2003 and June 2005. Preoperative and postoperative lateral radiographs were measured for height of intervertebral disc space where cages were placed intervertebral disc space was measured by dividing the sum of anterior, posterior, and midpoint interbody distance by 3. Follow-up time was 6 to 12 months. Subsidence was defined as any change in at least one of our parameters of at least 3 mm. Results : Subsidence was found in 22 patients (22%). The mean value of subsidence was 2.21 mm, and mean subsidence rate was 22%. There were no cases of the clinical status deterioration during the follow-up period No posterior or anterior migration was observed. Conclusion : The phenomenon of subsidence is seen in substantial number of patients. Nevertheless, clinical and radiological results of the surgery were favorable. An excessive subsidence may result in hardware failure. Endplate preservation may enables us to control subsidence and reduce the number of complications.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11a
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• pp.15-18
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• 2003

Recently, some researches related to air pollution problems in large cities of the Islamic Republic of Iran have been done. Famous institutes and research centers in countries like Japan, Sweden and Germany have been in cooperation with Iranian institutes in implementing the results. Due to quick increase in the population because of peoples＇ migration from countryside to cities, and rate of growth in the early years after the revolution, air pollution was an important problem in I.R.Iran. Therefore, air pollution control is one of the main issues in major cities of I.R. Iran. It is the purpose of this study to investigate the control mechanisms for air pollution problems in the major industrial cities. The necessary action plans that were taken in recent years in some of the cities, which were also suggested to be taken in the other ones, are the other purpose of this study. From the results of studies it was obtained in Iran, lots of researches are important to mention. Amongst the main activities that are done in recent years are： establishing of the meteorological research centers and atmosphere sciences; three applicator meteorological research centers and more than 40 new stations in the country; installation of newest computer systems in metrological information, using of wall map and continuous radio-traffic to announce traffic news; completing of subway construction in Tehran; forbidding of industrial activities in a definite distance away from Tehran and transferring them to suitable places; building of highways and freeways; improving of public transportation and gasifying them; developing of fuels quality and removing lead from them; and gasifying of the heating systems in houses and buildings.

• Journal of the Korean housing association
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• v.20 no.4
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• pp.103-112
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• 2009

The purpose of this research was to find out the housing history of Sakhalin returnees in Ansan Gohyangmaeul since leaving hometown under the Japanese ruling period, who experienced two international migration for one's life. Face to face interview had been done with 20 returnees in the community center of Ansan Gohyangmaeul during October to December, 2008. The semi-structured questionnaire about housing the respondents lived in major life changes used to guide the individual interview. The results showed that personal life as well as housing histories were differed by the reason to move into Sakhalin, which still influenced the returnee' life up to now. The housing they had lived changed from barracks like a training camp, to Japanese small wooden cottage/row house, and then Russian brick house/ apartment. Housing alteration and addition and rebuilding were common to renew the old existing house. The boundary of residing area was mostly limited to the first residing location under soviet governing system throughout one's life without a long distance move. Housing satisfaction was very high in Gohyangmaeul because of the improvement of housing facilities and residence itself as well as the convenience of housing management, compared to former residence in Sakhalin. Economic and emotional aspects of life satisfaction were also high during about 8 years of living in the apartment. Forced movers still require the compensation on hand to either Korean or Japanese government no matter the amount. Social integration to the Korean community would be one of the main issues to new returnees as well as the already returned. In-depth interviews of case study need to reveal the unique housing experience of the forced mover according to the type of leaving hometown by oneself or by parents, and to returned region and time to motherland.