• The Korean Journal of Malacology
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• v.23 no.1
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• pp.17-23
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• 2007

Samples of Potamocorbula ustulata ustulata were collected monthly from October 2004 to November 2005 in the Jujin estuary of Gochang, Chollabuk-do, west coast of Korean peninsula. Age of P. ustulata ustulata was determined by the rings on the shell. The relationship between the shell length and the ring diameter in each ring group was expressed as a regression line. Therefore, there is a correspondence in each ring formation. Based on the monthly variation of the marginal index (MI') of the shell, it is assumed that the ring of this species was formed once a year during October to December. The relationship between the shell length (SL) and the shell height (SH; mm) was highly correlated with shell height as the following equation: SH = 0.6438 SL + 0.5642 ($r^2\;=\;0.978$). The shell length (SL) - shell width (SW) relation was also expressed by the following equation: SW = 0.4352 SL - 0.5675 ($r^2\;=\;0.957$). Shell length (SL; mm) and the total weight (TW; g) followed: $TW\;=\;6.999\;{\times}\;10^{-5}\;SL^{3.2542}(r^2\;=\;0.975)$. Growth curves for the shell length and the total weight fitted to the von Bertalanffy's growth curve were expressed respectively as: $$SL_t=30.77[1-e^{-0.4572(t+0.7371)}],\;TW_t=4.87[1-e^{-0.4572(t+0.7371)}]^{3.2542}.$$

• Spatial Information Research
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• v.19 no.2
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• pp.9-18
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• 2011

The purpose of this research is to evaluate an accurate biotope area ratio model with efficiency and convenience of database management through promoting sustainable development to provide people amenities in a new town. In particular, the biotope area ratio is used not only in the environment impact assessment but Green building certification criteria. But now there is no any index map of biotope. So it is very hard to implement with data for supplement results. In this research, we suggest the model of integrated attributable information. The evaluation of biotope area ratio is to include a basic land use planning map and a building coverage area which is a wall of greening surface and roof. In case of non building coverage area, the evaluation of biotope area ratio is to include water space, artificial ground, natural ground and pervious gap-pave. A weighted value on the spatial information is combined into the information. And then the merged one is given a land use planning information in a block. In the weighted value on the space type information, it is possible to in its circumstances. Therefore, it can be substituted a correspondence of numerical change for various values elastically in this model.

• The Korean Journal of Malacology
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• v.25 no.3
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• pp.189-196
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• 2009

Based on 1,260 samples, the age and growth of purple whelk, Rapana venosa (Valenciennes) (Gastropoda:Muricidae) have been investigated. The samples were collected monthly during one year time (from February, 2004 to January, 2005) from the West Sea of Korea. The age of R. venosa was determined by the ring of the operculum analysis. The relationship between whelk's shell height and ring radius in each ring group was expressed as an equation of linear regression and later a correspondence in each ring formation was determined. Based on the monthly variations in the marginal index (MI) of the operculum, it was assumed that the ring of this species has been formed once a year during the period from July to August. The relationship between shell height and shell width was expressed by the equation SW = 0.7867 SH - 6.3988 ($R^2$=0.8604); and between shell height and total weight by the equation $TW=0.0000626{\times}SH^{3.206}$ ($R^2$=0.8324). The purple whelk's spawning period was estimated through the fatness analysis and has occurred during the period from May to July. Obtained results suggests that the ring formation occurs once a year (in July) and the length of time period since the first ring has been formed on the operculum is approximately 13 months (1.08 year). The purple whelk's growth curves for shell height and total weight fitted to the von Bertalanffy's equation and were expressed as follows: $SH_t=199.653(1-e^{-0.104(t+2.478)}$ $TW_t=1484.105(1-e^{0.104(t+2.478)})^{3.206}$.

• Korean Journal of Environmental Biology
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• v.41 no.2
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• pp.126-137
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• 2023

Paddy fields provide important habitats for biodiversity conservation within the agricultural ecosystem. Their importance is gradually increasing as their ecological value is better understood. Benthic macroinvertebrates dominate paddy fields. They play an essential role in maintaining the biodiversity of paddy ecosystems. This study aimed to analyze characteristics of benthic macroinvertebrate communities and main environmental factors affecting the distribution of golden apple snails (Pomacea canaliculata). Results showed that the diversity index (H') of the benthic macroinvertebrate community was the highest at the Sangju site (St. 12) but the lowest at the Sancheong site (St. 18). Total Dissolved Solids (TDS), salinity, and Electrical Conductivity (EC) values were the highest in Gimhae and Yeongam based on Canonical Correspondence Analysis (CCA). Numbers of P. canaliculata (m-2) were relatively low in Gunsan and Iksan where water temperatures were high. Therefore, changes in geographical characteristics and environmental factors might affect the distribution of P. canaliculata and characteristics of benthic macroinvertebrate communities. Results of this study can be used as primary data for biodiversity conservation and ecosystem service evaluation in agroecosystems.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.11 no.4
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• pp.152-157
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• 2006

Samples of Meretrix lusoria were collected monthly from the tidal flat of Simpo, Puan-gun, Chollabuk-do, west coast of Korea from April 2004 to March 2005. Age of M. lusoria was determined from the rings on the shell. The relationship between shell length and ring radius in each ring group was expressed as a regression line. Therefore, there is a correspondence in each ring formation. Based on the monthly variations in the marginal index (MI') of the shell, it is assumed that the ring of this species was formed once a year during the period of February to April. The relationship between shell length (SL) and shell height (SH; mm) was highly correlated with shell height as the following equation: SH = 0.8103 SL + 0.5145 $(r^2=0.991)$. The shell length (SL) - shell width (SW) relation was also expressed by the following equation: SW = 0.4897 SL + 0.0315 $(r^2=0.976)$. Shell length (SL; mm) and total weight (TW; g) was expressed by the following equation: $TW=2.9195\times10^{-4}\;SL^{2.9547}\;(R^2=0.991)$. Shell length (SL) and shell height (SH; mm) was highly correlated with shell height as the following equation: $SH=0.8103\;SL+0.5145\;(R^2=0.991)$ The shell length (SL) - shell width (SW) relation was also expressed by the following equation: $SW=0.4897\;SL+0.0315\;(R^2=0.976)$. Growth curves for shell length and total weight fitted to the von Bertalanffy's growth curve were expressed respectively as: $SL_t=104.9[l-e^{-0.2235(t+0.7677)}],\;TW_t=280.8[l-e^{-0.2235(t+0.7677)}]^{2.9547}$.

• Journal of agricultural medicine and community health
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• v.24 no.1
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• pp.13-33
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• 1999

The aim of this study was to investigate fatigue scores, physical complaints, farmer's syndrome and to find out its risk factors among farmers. The questionnaire survey was conducted to 177 vinyl house workers and 213 farmers who lived in Chongyang gun of Chungnam province from February 24 to March 15, 1998. The obtained main results were followings; 1. The fatigue scores were not significantly different between vinyl house workers and farmers. The fatigue scores were higher in female group, lower education group, shorter sleep hours group(under 8 hours), nonsmoker, nondrinker group than otherwise groups. There was not statistically significant difference between the mean fatigue scores and age, eating habit and body mass index. Duration of farming years in vinyl house and farming area and number of farming workers in farmers family showed a slight relationship with the fatigue score. 2. Health scores were not different between vinyl house workers and farmers. The health states was poorer in female group, lower education group, shorter sleep hours group(under 8 hours), nonsmoker group, and nondrinker group than otherwise groups by health scores. Health scores were not related with age, eating habit and body mass index. 3. The proportion of farmer's syndrome was 49.1% in vinyl house workers and 52.1% in farmers. That was higher in female than in male and the higher proportion was found in the lower education group of vinyl house workers and farmers. The proportion of farmer's syndrome was higher in the group of smoker, alcohol drinkers and over or under weight in vinyl house workers, but did not differ in those of farmers. 4. By multiple logistic regression, sex and sleep hours were risk factors affecting to farmer's syndrome. Odds ration for female group was 2.53 (reference group was male) and that for over 8 sleep hours group was 0.74 (reference group was under 8 sleep hours group). 5. The chief complaints by CMI were "I am difficult to work due to aching the back and the limbs", "I feel prickle pain in the limbs", "I sometimes have a twinge in the limbs", "I am not quite well as having a pain in the limbs", "I feel weaker grasping power than before" in both of vinyl house workers and farmers. Vinyl house workers more frequently pointed out skin darkening, skin disease and hemorrhoids than farmers. 6. According to correspondence analysis, skin disease of vinyl house workers was related to vinyl house farmers and digestive and general symptom was associated with male and endocrinological and muscular symptom was associated with female in vinyl house workers. And it revealed that farmer's syndrome was highly related with female and farmers relatively. By the above results, the fatigue scores, perceive health and farmer's syndrome did not much differ in two groups, but aged female farmers should be considered as female farmers represented higher fatigue score, farmers syndrome and poorer perceive health than male farmers in addition to farmer's syndrome was increased with ageing process. Also feeble but distinguished symptoms which might be due to working environment were observed especially in vinyl house workers and that should be considered and investigated continuously.

• Fisheries and Aquatic Sciences
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• v.26 no.12
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• pp.738-751
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• 2023

The Sembilan Archipelago is famous for its great biodiversity, in which the humphead wrasse (Cheilinus undulatus) (locally named Napoleon fish) is the primary commodity (economically important), and currently, the environmental degradation occurs due to anthropogenic activities. This study aimed to examine the eco-environmental parameters and assess their influence on the abundance of humphead wrasse and other coral reef fish compositions in the Sembilan Archipelago. Direct field monitoring was performed using a visual census throughout an approximately one km transect. Coral cover data collection and assessment were also carried out. A coastal water quality index (CWQI) was used to assess the water quality status. Furthermore, statistical-based analyses [hierarchical clustering, Pearson's correlation, principal component analysis (PCA), and canonical correspondence analysis (CCA)] were performed to examine the correlation between eco-environmental parameters. The Napoleon fish was only found at stations 1 and 2, with a density of about 3.8 Ind/ha, aligning with the dominant composition of the family Serranidae (covering more than 15% of the total community) and coinciding with the higher coral mortality and lower reef fish abundance. The coral reef conditions were generally ideal for supporting marine life, with a living coral percentage of about > 50% in all stations. Based on CWQI, the study area is categorized as good and excellent water quality. Of the 60 parameter values examined, the phytoplankton abundance, Napoleon fish, and temperature are highly correlated, with a correlation coefficient value greater than 0.7, and statistically significant (F < 0.05). Although the adaptation of reef fish to water quality parameters varies greatly, the most influential parameters in shaping their composition in the study area are living corals, nitrites, ammonia, larval abundance, and temperature.