• The Korean Journal of Nuclear Medicine
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• v.30 no.4
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• pp.476-483
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• 1996

Following radiation therapy for brain tumors, patients often have clinical deterioration due to either radiation necrosis or recurrent tumor progression in the treatment field. The distinction between these entities is important but difficult clinically or even with CT or MRI. T1-201 has been known to accumulate in various tumors and be useful to grade, predict prognosis or detect recurrence of glioma. The aim of this study was to evaluate the usefulness of T1-201 SPECT in the differentiation of recurrent tumor from radiation necrosis. Of 67 patients who did T1-201 brain SPECT imaging with clinically suspected recurrent tumor or radiation necrosis, 20 patients underwent histopathological examination and constituted the study population. T1-201 uptake indices on T1-201 brain SPECT imaging rrere calculated and correlated with histopathological diagnosis. Of 20 patients, 15 were histopathologically confirmed as recurrent original tumor or malignant transformation of benign tumor and 5 were diagnosed as radiation necrosis. On T1-201 SPECT, 18 of 20 had T1-201 index above 2.5 which was regarded as positive indicator for the presence of tumor. Seventeen cases showed concordance, which consisted of 15 true positive and 2 true negative. Discordant 3 cases were all false positive. There was no case of false negative. The sensitivity, specificity, positive and negative predictive value of T1-201 SPECT were 100%, 40%, 83% and 100%. In conclusion, T1-201 brain SPECT is a sensitive diagnostic test in the detection of recurrent tumor following radiation therapy and is useful in the differentiation of recurrent tumor from radiation necrosis. Relatively low specificity should be evaluated further in larger number of patients in consideration of sampling error and referral bias for pathologic examination.

• Korean Journal of Environmental Biology
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• v.36 no.2
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• pp.180-189
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• 2018

Agricultural landscapes in Korea comprise a large cultivation area of rice paddies, other crops, and forests which surround the cropland and the farmers' residential village. The forests in this agricultural landscape play important roles as ecological corridors and refuges for plants and animals in this agroecosystem. The present study investigated the spatial and temporal diversity patterns among these components of the agroecosystem to provide baseline data that describes how fauna change in the studies system. Insect sampling was conducted at four sites in two regions, Chungcheong (Ockcheon and Geumsan) and Jeonnam (Younggwang and Haenam), from March to August of 2014, using an UV light trap for moths and five pitfall traps for beetles. Beetles comprised 225 species and 2,457 individuals in 35 families, while moths consisted of 141 species and 403 individuals in 17 families. Beetles showed higher diversity in Chungcheong than Jeonnam, while moths showed no difference in diversity between regions. Forests showed the highest number of species and individuals, followed by orchards and rice paddies. The food preference of beetles showed that forests contained a higher proportion of herbivores, while orchards and rice paddies had a higher proportion of carnivores. Temporal changes in moths in the two regions were synchronous, while those of beetles were nonsynchronous. Moths increased from spring to summer across all habitats, especially in rice paddies during summer. Beetles also increased from spring to summer in orchards and rice paddies, although the beetles in the forests increased in the middle of summer. A detailed and long-term study is needed to reveal the causes of different diversity patterns of taxa among the different habitats within the agroecosystems.

• Journal of Environmental Impact Assessment
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• v.26 no.6
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• pp.418-430
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• 2017

The quality of surface water is a very important issue to use various demands like as drinking water, industrial, agricultural and recreational usages. There has been an increasing demand for monitoring water quality of many rivers by regular measurements of various water quality variables. However precise and effective monitoring is not enough, if the acquired dataset is not analyzed thoroughly. Therefore, the aim of this study was to estimate differences of seasonal and regional water quality using multivariate data analysis for each investing tributaries in Han River. Statistical analysis was applied to the data concerning 11 mainly parameters (flow, water temperature, pH, EC, DO, BOD, COD, SS, TN, TP and TOC) for the time period 2012~2016 from 12 sampling sites. The seasonal water quality variations showed that each of BOD, TN, TP and TOC average concentration in spring and winter was higher than that of summer and fall, respectively. In summer each flow rate and average concentration of SS was higher than any other seasons, respectively. The correlation analysis were explained that EC had a strong relationship with BOD (r=0.857), COD (r=0.854), TN (r=0.899) and TOC (r=0.910). According to principal component analysis, five principal components (Eigenvalue > 1) are controlled 98.0% of variations in water quality. The first component included TP, DO, pH. The second component included EC, TN. The third component included SS. The fourth component included flow. The last component included Temp. Cluster analysis classified that spring is similar to fall and winter with water quality parameters. AnyA, WangsA, JungrA and TancA were identified as affected by organic pollution. Cluster analysis derived seasonal differences with investigating sites and better explained the principal component analysis results.

• Korean Journal of Ecology and Environment
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• v.38 no.1 s.110
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• pp.1-10
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• 2005

Macroinvertebrates from a first order stream at Mt Jumbong, Kangwon-do, was examined for their abundance and biomass. Sampling was done by using a pipe sampler (${\phi}$ 20 cm) for 11occasions (n = 5) at 4${\sim}$6 weeks intervals during November 1997 through October 1998. Water temperature and electronic conductivity of the study stream ranged $0\;{\sim}\;14^{\circ}C$ and 15${\sim}$25 ${\mu}s$/cm, respectively. During the study, 53 insect taxa and 3 non-insect taxa were collected. Annual mean number of individuals (${\pm}$1 SD) was 77741${\pm}$69232${\cdot}$m$^{-2}$ ${\cdot}$yr$^{-1}$, being high in winter (${\pm}$1 SD) (December: 171178${\pm}$130468 $m^{-2}$) and low in summer (${\pm}$ 1 SD) (June: 29872${\pm}$13078 $m^{-2}$). Non-predatory subfamilies of Chironomidae and Nemoura sp. occupied 53.3% and 21.8% of annual abundance. Annual mean biomass was 10g${\cdot}$m$^{-2}$${\cdot}$yr$^{-1}$ in ash free dry weight (AFDW), being high in late winter (February: 16 gAFDW $m^{-2}$.) and low in summer (June: 3 gAFDW $m^{-2}$). Gammarus sp. represented 39.8% of the total biomass and was followed by non-predatory subfamilies of Chironomidae (15.2%) and Hydatohylax sp. (8.5%, Limnephilidae: Trichoptera). Since the non-predatory subfamilies of chironomidae were composed of many species, Nemoura sp. was the most abundant taxon. However, Cammarus sp. was surely the most important taxon to the functional aspects of this first order stream ecosystems.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.1
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• pp.1-10
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• 1982

Degree of grain shattering which is of varietal character is an important determinant for the magnitude of field loss of grains during harvest and threshing. Seven Indica \times Japonica progeny varieties and four Japonica varieties were subjected to measurements of tensile strength of grains, degree of grain shattering when panicles were dropped at 1.5m above concrete floor, and moisture content of grains (wet basis) during a period 35 to 63 days after heading. In addition, two varieties were tested for the relation of tensile strength of grains to the magnitude of field loss of grains in actual binder harvest. The 11 varieties differed conspicuously in tensile strength of grains and the degree of grain shattering: the weakest average tensile strength of grains of a variety was about 90g and the strongest about 250g with varying standard deviation of 30 to 60g. Three Indica \times Japonica varieties and one Japonica variety shattered I to 30% of the grains under the falling test. The threshold tensile strength of grains allowing grain shattering was estimated to be 180g on average for a sampling unit of 10 panicles, but only the grains having tensile strength weaker than 98g within the samples shattered. A decrease in average tensile strength by 10g below the threshold value corresponded to an increase of 3 to 5% in grain shattering. Most varieties did not change appreciably the tensile strength of grains and degree of grain shattering with delay in time of harvest and showed a negative correlation between the tensile strength and the moisture content of grains. The average tensile strength of grains was negatively correlated linearly with field loss in binder harvest. The average tensile strength for zero field loss in binder harvest was estimated to be 174g and a decrease in the average tensile strength by 10g corresponded to an increase of 40kg per hectare in field loss of grains. Instead of the average tensile strength of grains, the percentage of grains having tensile strength weaker than 100g is recommended as a criterion for the estimation of field loss of grains during harvesting operations as well as a basis of variety classification for grain shattering, since the standard deviation of tensile strength of grains varies much with variety and time of harvest, and individual grains having tensile strength stronger than 98 did not shatter practically.

• Korean Journal of Ecology and Environment
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• v.43 no.1
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• pp.129-135
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• 2010

The relationship between rainfall variable and zooplankton dynamics was studied in the Upo wetland, an ecosystem of international importance. Water sampling was conducted on biweekly basis from January 2002 to December 2007 in the study site. The annual average of total rainfall was 1,324 mm during the study period. Total rainfall amount in 2003 (1,766 mm) was unusually high, while total rainfall amount in 2005 (975 mm) was exceptionally lower than the average. Most of basic limnological parameters (water temperature, dissolved oxygen, pH, conductivity and turbidity) in the study site were greatly influenced by the flooding events and rainfall amounts in summer. There were statistically significance between seasonal and inter-annual differences in zooplankton abundance and the total rainfall amount (ANOVA, P<0.05). Zooplankton abundance was high in summer (mean${\pm}$s.d.: $1,594{\pm}1,598\;Ind.\;L^{-1}$) and low in winter ($246{\pm}234\;Ind.\;L^{-1}$. The 47% of annual total zooplankton abundance in the study site were observed in summer. The seasonal pattern of rotifers was similar to that of total zooplankton. This reflected the fact that rotifers strongly dominated and occupied ca. 65% the total zooplankton abundance (annual mean: $398{\pm}1,139\;Ind.\;L^{-1}$, n=149), followed by cladocerans ($65{\pm}140\;Ind.\;L^{-1}$) and copepods ($58{\pm}84\;L^{-1}$). Planktonic rotifers such as Keratella cochlearis, Polyarthra spp. and Brachionus calyciflorus were dominant from winter to spring and attached rotifers such as Lecane spp., Monostyla spp. and Trichocerca spp., observed commonly from spring to fall. Among the environmental variables considered, rainfall in summer seemed to play the most important role in determining characteristics of zooplankton community dynamics in the Upo wetland.

• Tuberculosis and Respiratory Diseases
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• v.65 no.4
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• pp.269-276
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• 2008

Background: Although the prevalence of tuberculosis infections (PTBI) is one of the basic epidemiologic indices, no survey has been carried out since 1995 because the nation-wide tuberculosis prevalence survey was changed to a surveillance system. Subjects without a BCG scar are examined in a tuberculin survey. However, it is very difficult to select these subjects under high vaccination coverage. It is important to evaluate the impact of BCG vaccinations on the tuberculin response and estimate the PTBI regardless of the BCG vaccination status. Methods: A nation-wide, school-based cross-sectional tuberculin survey was carried out among first graders in elementary school in 2006. A total of 5,148 children in 40 schools were selected by quota sampling. Tuberculin testing with 0.1 ml of two tuberculin units of PPD RT23 was carried out on 4,018 children. The maximum transverse diameter of induration was measured 48 to 72 hours later. The presence of a BCG scar was checked separately. Results: There were no BCG scars in 6.3% of the subjects. The mean induration size of tuberculin testing was $3.7{\pm}4.4mm$, which included 1,882 (46.8%) subjects with an induration size of 0 mm. The PTBI was 10.9% (439 subjects) using a cut-off point of ${\geq}10mm$ (conventional method). The annual risk of tuberculosis infections (ARTI) was 1.9% when the mean age of the subjects was assumed to be 6 years. There was no difference in the PTBI according to the presence or absence of a BCG scar [11.2% vs 7.6% (OR: 1.54, 95% CI: 0.98~2.43)]. Using a mirror image technique with 16 mm as the cut-off point, the PTBI and ARTI had decreased to 2.4% and 0.4% respectively. Conclusion: PTBI and ARTI, as estimated by conventional methods, appear to be high among BCG vaccinated children. A mirror image technique is more suitable for estimating the indices in a country with an intermediate burden of tuberculosis than the conventional method.

• Management & Information Systems Review
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• v.3
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• pp.287-316
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• 1999

Cyberspace permits us to more beyond traditional face-to-face, mail and telephone surveys, yet still to examine basic issues regarding the quality of data collection: sampling, questionnaire design, survey distribution, means of response, and database creation. This article address each of these issues by contrasting and comparing traditional survey methods(Paper-and-Pencil) with Internet or Personal Computer networks-mediated (Screen-and-Keyboard) survey methods also introduces researchers to this revolutionary and innovative tool and outlines a variety of practical methods for using the Internet or Personal Computer Networks. The revolution in telecommunications technology has fostered the rapid growth of the Internet all over the world. The Internet is a massive global network and comprising many national and international networks of interconnected computers. The Internet or Personal Computer Networks could be the comprehensive interactive tool that will facilitate the development of the skills. The Internet or Personal Computer Networks provides a virtual frontier to expand our access to information and to increase our knowledge and understanding of public opinion, political behavior, social trends and lifestyles through survey research. Comparable to other technological advancements, the Internet or Personal Computer Networks presents opportunities that will impact significantly on the process and quality of survey research now and in the twenty-first century. There are trade-offs between traditional and the Internet or Personal Computer Networks survey. The Internet or Personal Computer Networks is an important channel for obtaining information for target participants. The cost savings in time, efforts, and material were substantial. The use of the Internet or Personal Computer Networks survey tool will increase the quality of research environment. There are several limitations to the Internet or Personal Computer Network survey approach. It requires the researcher to be familiar with Internet navigation and E-mail, it is essential for this process. The use of Listserv and Newsgroup result in a biased sample of the population of corporate trainers. However, it is this group that participates in technology and is in the fore front of shaping the new organizations of interest, and therefore it consists of appropriate participants. If this survey method becomes popular and is too frequently used, potential respondents may become as annoyed with E-mail as the sometimes are with mail survey and junk mail. Being a member of the Listserv of Newsgroup may moderate that reaction. There is a need to determine efficient, effective ways for the researcher to strip identifiers from E-mail, so that respondents remain anonymous, while simultaneously blocking a respondent from responding to a particular survey instrument more than once. The optimum process would be on that is initiated by the researcher : simple, fast and inexpensive to administer and has credibility with respondents. This would protect the legitimacy of the sample and anonymity. Creating attractive Internet or Personal Computer Networks survey formats that build on the strengths of standardized structures but also capitalize on the dynamic and interactive capability of the medium. Without such innovations in survey design, it is difficult to imagine why potential survey respondents would use their time to answer questions. More must be done to create diverse and exciting ways of building an credibility between respondents and researchers on the Internet or Personal Computer Networks. We believe that the future of much exciting research is based in the Electronic survey research. The ability to communicate across distance, time, and national boundaries offers great possibilities for studying the ways in which technology and technological discourse are shaped. used, and disseminated ; the many recent doctoral dissertations that treat some aspect of electronic survey research testify to the increase focus on the Internet or Personal Computer Networks. Thus, scholars should begin a serious conversation about the methodological issues of conducting research In cyberspace. Of all the disciplines, Internet or Personal Computer Networks, emphasis on the relationship between technology and human communication, should take the lead in considering research in the cyberspace.

• Journal of dental hygiene science
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• v.16 no.1
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• pp.26-36
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• 2016

The purpose of this study was to examine how oral health literacy of mothers affect the oral health status of their preschool children. The subjects were 233 mothers and their preschool children who are between 5 and 6 years old. They were selected according to the convenience sampling method. The individual self-administered questionnaire was used for the mother's survey while the children were interviewed using structured questionnaire to examine their oral health status and behavior. According to study results, the number of decayed primary teeth and the number of decayed and filled primary teeth had a statistically significant negative correlation with the oral health literacy of the mother, the children's oral health knowledge, attitude and behavior (COHKAB), and the mother's oral health management behavior. Hierarchical multiple regression analysis was performed after including general characteristics variables, the COHKAB and the mother's oral health management behavior. Meanwhile, mother's oral health literacy had a statistically influence on children's oral health status. The higher the mother's oral health literacy level, the lower the number of decayed and filled primary teeth were. The findings suggest that efforts to improve the oral health status of preschool children should consider mother's oral health literacy as an important factor. Therefore, the effective intervention and education programs are necessary to enhance mother's oral health literacy.

• The Korean Journal of Soil Zoology
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• v.6 no.1_2
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• pp.25-31
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• 2001

Oribatid mite communities in the process of litter decomposition were analyzed In Korean pine (Pinus koraiensis) forests of Namsan and Kwangreung, which were supposed to be under different environmental selective pressures. Oribatid mites were collected bimonthly from the litter bags (mesh size 0.4 mm, 1.7 mm) which was set up in the forest floor of study sites. This study had been carried out from Jan., 1997 to Sept., 1998. Species abundance of Kwangreung (mesh size 1.7 mm) was significantly higher than that of Namsan (mesh size 1.7 mm), but total no. of species did not exceed 30 species in all study sites. Concerning body length, medium sized oribatid mites (0.3-0.7mm) were more abundant than small ( < 0.3 mm) and large ( > 0.7 mm) sized mites. In Kwangreung, species whose body lengths were 0.2 mm to 0.5 mm were major group. However, a little larger species than Kwangreung's major group were dominant in Namsan. Sorenson similarity index and cluster analysis suggested that there were qualitative and quantitative differences in species composition in Namsan and Kwangreung. More species were collected in May through September than the other sampling times, but the pattern was rather different between first year and second year. Newly immigrant species were high in May in the first year and many of them regained on next year. Diversity indices suggested that species diversity of Kwangreung was higher than that of Namsan. Nearly 70% of total individual abundance was occupied by several dominant species in Namsan and Kwangreung . In the litter bags of mesh size 1.7 mm, the most dominant species was Trichogalumna nipponica in Namsan and Kwangreung, but in the litter bags of mesh size 0.4 mm in Kwangreung it was Ramusella sengbuschi which is smaller than T. nipponica. And important species related to litter decomposition were selected as follows; T. nipponica, Epidamaeus coreanus, Scheloribates latipes, Ceratozetes japonicus, Ramusella sengbuschi, Eohypochthonius crassisetiger, and Cultroribula lata.