• Journal of Forest and Environmental Science
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• v.33 no.3
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• pp.239-242
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• 2017

Although camera traps have been widely used to understand the abundance of wildlife in recent decades, the effort has been restricted to small sub-set of wildlife which can mark-and-recapture. The Random Encounter Model shows an alternative approach to estimate the absolute abundance from camera trap detection rate for any animals without the need for individual recognition. Our study aims to examine the feasibility and validity of the Random Encounter Model for the density estimation of endangered leopard cats (Prionailurus bengalensis) in Maekdo riparian park, Busan, South Korea. According to the model, the estimated leopard cat density was $1.76km^{-2}$ (CI 95%, 0.74-3.49), which indicated 2.46 leopard cats in $1.4km^2$ of our study area. This estimate was not statistically different from the previous leopard cat population count ($2.33{\pm}0.58$) in the same area. As follows, our research demonstrated the application and usefulness of the Random Encounter Model in density estimation of unmarked wildlife which helps to manage and protect the target species with a better understanding of their status.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.5
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• pp.493-498
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• 2012

We derived biological reference points for Pacific cod Gadus macrocephalus in southeastern Korean waters by applying a yield-per-recruit analysis based on a daily simulation that adopted size-dependent fecundity, growth, and natural mortality functions. This showed that the yield per recruit of Pacific cod can be maximized at an instantaneous rate of fishing mortality (F)=0.37 $yr^{-1}$ under the current regulations, where the minimum catch size ($L_c$)=30 cm in total length (TL). The maximum economic yield was estimated to be attained at $L_c$=35-45 cm TL, if F>1 $yr^{-1}$ but at $L_c$=35-40 cm TL, if F<1 $yr^{-1}$. Despite great uncertainty in the stock assessment, to develop fisheries management plans for the sustainable exploitation of Pacific cod in southeastern Korean waters, it is necessary to estimate F using capture-recapture or other expedient methods.

• Journal of Aquaculture
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• v.22 no.1
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• pp.16-22
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• 2009

Life history of Korean crayfishes Cambaroides similis (Koelbel) was studied 8 month from March to October, 2006 from the Gwanak mountain, Seoul, South Korea. By capture and recapture method, 551 crayfishes were collected analyzed during the experimental period. Based on the distribution pattern of body lengths, the local population putatively divided into four age groups. The sex ratio of male and female was almost equal. However, their growth rates varied by water temperature. Early juveniles seen during June became adult during August. The study findings suggest that late autumn is mating season.

• Journal of Oral Medicine and Pain
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• v.36 no.1
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• pp.71-79
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• 2011

Aim: Disc displacement without reduction of the temporomandibular joint (TMJ) has been managed by mandibular manipulation to reduce the displaced disc but with a low success rate. The purpose of this study was to determine whether auriculotemporal nerve block anesthesia had an effect on the reduction of the displaced disc and to analyze the factors that influenced the result. Methods: 112 patients were diagnosed with disc displacement without reduction and treated by mandibular manipulation. Disc was recaptured in 35 patients. Among the 77 patients with whom disc recapture had failed, the auriculotemporal nerve was blocked with a local anesthetic in the 49 patients (mean $age \;{\pm}\; SD\; =\; 34.4\;{\pm}\; 15.1$; male 24, female 25) and then mandibular manipulation was performed again. Factors including age, elapsed time from the onset, and opening amount were analyzed in association with disc reduction rate with the auriculotemporal nerve block. Results: Among 49 patients who did not respond to manipulation only, manual reduction with auriculotemporal nerve block anesthesia was successful in 19 patients (38.8%). Maximum unassisted opening amount significantly increased in the 19 patients with successful recapture of the disc ($mean \;{\pm}\; SD\; =\; 46.1 \;{\pm}\; 4.5\; mm$), in contrast to the limited opening amount of the 49 patients before local anesthesia of the auriculotemporal nerve ($mean \;{\pm}\; SD\; =\; 25.7 \;{\pm}\; 6.0\; mm$). Age, elapsed time after the onset, and preoperative opening amount were not associated with the reduction rate. Conclusion: The results of this study suggest that auriculotemporal nerve block anesthesia increases the reduction rate of the disc displacement without reduction of the TMJ when combined with mandibular manipulation, and such anesthesia should be applied at the first stage of manual treatment of disc displacement without reduction.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.2
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• pp.363-370
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• 2015

Olive flounder, Paralichthys olivaceus is one of the most target fish for aquaculture and national stock enhancement program in Korea. In order to find more information about hatchery fish stocking for stock enhancement we investigated the sex ratio of wild-caught fish populations which were artificially released into wild seas. The recapture rate was 9.0% to 94.5% in studied areas. The proportion of sex ratio ranged from 7.8% to 64.6% in female and from 34.4% to 92.1% in male respectively. This result suggests that the sex ratio of wild populations might be effected by the released fish. So we need more careful stocking program of the fish to preserve the balance of the sex ratio in the wild population.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11c
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• pp.639-646
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• 2000

Hot air heater with light oil combustion is the most common heater for greenhouse heating in the winter season in Korea. However, since the heat efficiency of the heater is about 80%, considerable unused heat in the form of exhaust gas heat discharges to atmosphere. In order to capture this exhaust gas heat a heat recovery system for plant bed heating in the greenhouse was built and tested in the hot air heating system of greenhouse. The system consists of a heat exchanger made of copper pipes, ${\phi}\;12.7{\times}0.7t$ located inside the rectangular column of $330{\times}330{\times}900mm$, a water circulation pump, circulation plastic pipe and a water tame The total heat exchanger area is $1.5m^2$, calculated considering the heat exchange amount between flue gas and water circulated in the copper pipes. The system was attached to the exhaust gas path. The heat recovery system was designed as to even recapture the latent heat of flue gas when exposing to low temperature water in the heat exchanger. According to performance test it can recover 45,200 to 51,000kJ/hr depending on the water circulation rates of 330 to $690{\ell}$/hr from the waste heat discharged. The exhaust gas temperature left from the heat exchanger dropped to $100^{circ}C$ from $270^{circ}C$ by the heat exchange between the water and the flue gas, while water gained the difference and temperature increased to $38^{circ}C$ from $21^{circ}C$ at the water flow rate of $690{\ell}$/hr. And, the condensed water amount varies from 16 to $43m{\ell}$ at the same water circulation rates. This condensing heat recovery system can reduce boiler fuel consumption amount in a day by 34% according to the feasibility study of the actual mimitomato greenhouse. No combustion load was observed in the hot air heater.

• Journal of Environmental Science International
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• v.29 no.8
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• pp.809-818
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• 2020

To conserve the population of a hesperiid butterfly, Leptalina unicolor, inhabiting the protected areas of Jaeyaksan, we provide ecological information on their behavior and propose habitat conservation measures, such as the creation of alternative habitats based on comprehensive information. The behavioral study used a method of re-capture after releasing the butterfly with enamel marks on the wings. Adult behaviors were shown in four patterns: flying, settling on a plant, nectar absorption, and water absorption. Both males and females had the highest proportion of flight movement overall; however, males had a slightly higher proportion of flight movement. As for duration, females spent more time settling on plants to select spawning sites, and males seemed to take a longer time for water absorption activities, to absorb minerals needed to form the spermatophore. The average travel distance of butterflies was 27.5 m for females and 46.7 m for males, with daily activity ranges from 11.2 m to 43.8 m, and 21.4 to 57.6 m, respectively. The most important condition to preserve the habitat of Leptalina unicolor is to maintain the community of Miscanthus sinensis, a food plant. Additionally, because this butterfly has a high rate of water absorption activities, wetlands should be maintained.

• Parasites, Hosts and Diseases
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• v.43 no.3 s.135
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• pp.75-92
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• 2005

Extensive previous studies on taxonomy, behavior/bionomics and control of Anopheles sinensis are reviewed and summarized. Recent molecular identification revealed that the population of An. sinensis complex includes An. sinensis, An. pullus, An. lesteri and at least two new species, and An. yatsushiroensis is synonmy of An. pullus. An. sinensis is the main vector specie of vivax malaria in Korea. Larvae of An. sinensis breed in wide range of habitats which are naturally-made clean water, stagnant or flowing; main habitats include rice fields, ditches, streams, irrigation cannals, marshes, ponds, ground pools, etc. Their host preferences are highly zoophilic. Human blood rate is very low ($0.7-1.7\%$); nevertheless An. sinensis readily feeds on man when domestic animals are not found near by. They feed on hosts throughout the night from dusk to dawn with a peak period of 02:00-04:00 hours; they are slightly more exophagic (biting outdoors); much larger numbers come into the room when light is on. Main resting places are outdoors such as grasses, vegetable fields and rice fields. A mark-release-recapture study resulted that $37.1\%$ was recaptured within 1 km, $29.4\%$ at 1-3 km, $21.1\%$ at 3-6 km, $10.3\%$ at 6-9 km and $2.1\%$ at 9-12 km distance. An. sinensis hibernate outdoors (mostly under part of dense grasses) during October-March. At the end of the hibernation period (March-April) they feed on cows at daytime. Until today any single measure to effectively control An. sinensis population has not been found. Indoor residual spray with a long-lasting insecticide can not reduce vector population densities, but shorten their life spans in some degree, so contributes to malaria control.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.2 no.2
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• pp.114-119
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• 2021

To restore the Gold-spotted pond frog (Pelophylax chosenicus), a Korean endangered frog, 600 captive-reared individuals were reintroduced between August and September 2019 into an aquatic garden in the National Institute of Ecology where P. chosenicus had previously inhabited. After reintroduction, six post-release monitoring sessions were conducted from August 2019 to May 2020. Monitoring was performed using three methods (counting calls, observation, and capture) from sunset to midnight near release sites, eliminating potential threat factors. Snout-vent lengths and body weights of recaptured individuals were measured before they were released immediately. We noted that both snout-vent lengths and body weights of recaptured individuals were slightly higher than those before. The average recapture rate was 4.66%. Reintroduced frogs were recaptured at the last monitoring session conducted in May 2020, indicating that these reintroduced frogs hibernated during the winter successfully. We found that these reintroduced frogs successfully settled after release. This result will be useful for establishing management strategies for endangered frogs in Korea. Particularly, post-release monitoring could be an essential approach in the restoration program of a target species.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.41 no.1
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• pp.1-8
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• 2005

In order to find out the environmental factors influencing movement of common grey mullet, Mugil cephalus in funnel net fishing ground of the Dolsan-do, Yeosu southern sea area, the oceanographic factor such as the water temperature, isobath and tidal current were observed respectively, the water temperature was compared with the amount of common grey mullet caught by funnel net. Also, to investigate the movement direction of common grey mullet in same sea area, 160 common grey mullets of body length 22 to 51cm caught at funnel nets of the Dolsan-do southern sea area were marked and then released at 5 positions in 5 times. The results obtained are summarized as follows : 1. The water temperature at the funnel net fishing ground of Dolsan-do in 2002 was ranged from 6.9 to 27.4$^{\circ}C$. The water temperature was displayed a maximum value in August to increase from March and a minimum value in February of the ensuing year to decrease from September. The catches of gray mullet caught by funnel net were generally abundant from March to September, but decreased sharply from October. The optimum range of water temperature for the funnel nets fishing was situated between 15.0 to 25.0$^{\circ}C$. 2. The isobath from 6m to 13m in coast sea set up funnel nets were densely distributed and the depth more than 14m of isobath were widely spreaded to the open sea at Dolsan-do southern sea area. 3. The tidal current of the coast sea set up funnel nets flowed southward and northward along the coast ato ebb and flood tide respectively. The direction of tidal current to the open sea was southeast at ebb tide with the mean speed 43cm/sec, but northwest at flood with the mean speed 25cm/sec. 4. The recapture rate through the experiment duration showed 9.4%. The recapture rate in Gyedong area was very high value with 33.3% as compared with others. The movement of common grey mullet in Dolsan-do southern sea area trended toward a inner bay and north bound mainly.