• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.5
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• pp.719-729
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• 1997

Stomach contents of bigeye tuna, Thunnus obesus, and yellowfin tuna, Thunnus albacares, caught by longlining in the western tropical Pacific were analyzed to examine their foods and to compare their feeding behavior. The food species of both bigeye and yellowfin tunas were primarily fishes, crustaceans, and cephalopods. A total of 15 fish, 6 crustacean, and 1 cephalopod species were identified from their stomach contents, of which lantern fish (Myctophum sp.) was the most important food for both tuna species. No significant differences in species composition of food items between bigeye and yellowfin tunas were observed, indicating that in the same habitat the tunas have a similar feeding behavior. However, while they showed a remarkable similarity in diet composition, significant quantitative differences on the basis of IRI values were observed in several diet species, such as Myctophidae, Alepisauridae, Oplophoridae, Gammaridae, and Onychoteuthidae.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.6
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• pp.506-510
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• 1985

It is an important work to determine the mesh size of gill net for efficient catch. For investigating the suitable mesh size, the gill net for anchovy, Engraulis japonica was made and operated in the bay of Ulsan in July. 1983. The gill net for anchovy was composed of six different mesh size, 23.1mm (H=0.65), 21.6mm (H=0.65), 20.0mm (H=0.65), 23.1mm (H=0.55), 21.6mm (H=0.55) and 20.0mm(H=0.55). The parts of body caught by the gill net was examined, and the selectivity curves (for reference Ishida's method) with respect to the each mesh size were estimated using the data obtained through the operation of research gill net. The main results of this study are as follows: 1. The number of anchovy whose neck was in net was 148, more than $90\%$ of all, 161 2. The coefficient of relationship between the circumference of neck and the fork length were 0.70. 3. Fork length that the relative fishing efficiency of 23.1 mm mesh size (H=0.55) was maximum value was about 11.1 centimeter.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.5
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• pp.486-492
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• 2012

In the late 1970s, the National Fisheries Research & Development Institute (NFRDI) started cetacean research to submit the Korean whale catch record to the International Whaling Commission. This continued until the moratorium on commercial whaling in 1986. The NFRDI resumed cetacean research with a pilot whale sighting survey in 1999. Subsequently, the NFRDI has conducted 53 cetacean sighting surveys within the Korean exclusive economic zone between 2000 and 2010. The surveys took a total of 760 days and cruising for 23,866 nautical miles. The finless porpoise Neophocaena asiaeorientalis was sighted most frequently (735 times), followed by the minke whale Balaenoptera acutorostrata (396 times), the long-beaked common dolphin Delphinus capensis (102 times), and the Pacific white-sided dolphin Lagenorhynchus obliquidens (27 times). Minke whales were distributed in the Yellow Sea and coastal area of the East Sea from spring to fall. Pacific white-sided dolphin sightings were restricted to the middle and upper coastal areas of the East Sea in summer. Common dolphins were sighted from east of the southern coast to the eastern coast of the Korean Peninsula from spring to fall. Finless porpoise occurred in all Korean coastal areas, except the middle and upper eastern coast.

• Fisheries and Aquatic Sciences
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• v.19 no.5
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• pp.26.1-26.8
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• 2016

Background: The nematode species belonging to genus Anisakis occur at their third larval stage in numerous marine teleost fish species worldwide and known to cause accidental human infection through the ingestion of raw or undercooked fish or squids. They may also draw the attention of consumers because of the visual impact of both alive and dead worms. Therefore, the information on their geographical distribution and clear species identification is important for epidemiological survey and further prevention of human infection. Results: For identification of anisakid nematodes species isolated from largehead hairtail (Trichiurus japonicus), polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of internal transcribed spacers of ribosomal DNA were conducted. Mitochondrial cytochrome c oxidase subunit 2 gene was also sequenced, and phylogenetic analysis was conducted. From the largehead hairtail (n = 9), 1259 nematodes were isolated in total. Most of the nematodes were found encapsulated throughout the viscera (56.2 %, 708/1259) or moving freely in the body cavity (41.5 %, 523/1259), and only 0.3 % (4/1259) was found in the muscles. By PCR-RFLP, three different nematode species were identified. Anisakis pegreffii was the most dominantly found (98.7 %, 1243/1259) from the largehead hairtail, occupying 98.7 % (699/708) of the nematodes in the mesenteries and 98.1 % (513/523) in the body cavity. Hybrid genotype (Anisakis simplex ${\times}$ A. pegreffii) occupied 0.5 %, and Hysterothylacium sp. occupied 0.2 % of the nematodes isolated in this study. Conclusions: The largehead hairtail may not significantly contribute accidental human infection of anisakid nematode third stage larvae because most of the nematodes were found from the viscera or body cavity, which are not consumed raw. But, a high prevalence of anisakid nematode larvae in the largehead hairtail is still in concern because they may raise food safety problems to consumers. Immediate evisceration or freezing of fish after catch will be necessary before consumption.

• Journal of Korean society of Dental Hygiene
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• v.11 no.5
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• pp.729-739
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• 2011

Objectives : It is important to catch individual characteristics by measuring the level of self-efficacy, radiation safety knowledge, attitudes to increase behavior levels in the radiation safety management(RSM) and we consider this should be applied to the professional program development to improve RSM activities of dental hygienist and students at department of dental hygiene. Methods : This study mentioned mainly self-efficacy, radiation safety knowledge, attitudes for dental hygienists and the second & third year students at department of dental hygiene in Pusan area to provide the correct information associated with the use of radiation and to be aid in the development program to increase behavior levels in the RSM in dental care institutions and schools in the future and performed a survey 8 May to 7 Juiy, 2011. The survey results were as follows Results : 1. The results of self-efficacy is $3.53{\pm}0.42$ points for the dental hygienist and $3.32{\pm}0.40$ points for students(p<0.001). 2. According to the knowledge level of RSM, the result is $11.7{\pm}3.12$ points for the dental hygienist and $9.56{\pm}2.72$ points for students(p<0.001). 3. According to the knowledge level of RSM, the result is $4.40{\pm}0.49$ points for the dental hygienist and $4.22{\pm}0.56$ points for students(p<0.001). 4. According to relationship among self-efficacy, radiation safety knowledge and attitudes, the higher the score for knowledge of RSM was, the higher the score for self-efficacy was. The higher the score for attitudes was, the higher the score for self-efficacy and knowledge was(p<0.01). 5. The factors to affect attitudes about RSM were self-efficacy, knowledge(p<0.01).

• Design & Manufacturing
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• v.12 no.2
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• pp.27-33
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• 2018

Korea's automobile industry, which has grown rapidly to become the world's fifth-largest automobile producer, To cope with environmental pollution and energy problems in order to prevail competitive edge in global market We are investing a lot of research personnel and costs. Among them, for realizing alternative light weight It is a part of the automobile module system that has achieved the technological development before the breakthrough in the injection molding process in the press process. Door module PNL was the subject of research. The door module PNL is expected to cause warpage before the mold production due to the thin and flat product characteristics and fiber orientation characteristic of the material. In this paper, CAE analysis and reverse correction tool Design. CAE analysis to obtain the results of weld line position, bending position and deformation value Through the correction tool, think3, the original product was modified before the mold production to improve the completeness of the parts. In fiber orientation, the position and size of the cooling channel in the mold, the position and size of the gate, Temperature, pressure, time, and work environment. Compared with the result of CAE analysis, the product that was reverse-corrected by Think3 was manufactured, and injection molding was performed. Injection molding products were tested 24 hours later. 3.5 mm to 7.0 mm, and under the fixed condition, the deviation was from 1.1 mm to 1.5 mm. Unlike the CAE analysis, the deviation of the actual injection pressure and the cooling temperature, the fiber orientation of the material, In order to solve this problem, it is necessary to compare the injection conditions with the database, I knew I had to catch the standard.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.30 no.3
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• pp.142-149
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• 1994

In order to investigate the environmental properties of set net grounds located in the coastal waters of Yeosu. The current in the vicinity of set net grounds was observed by drogue and current meter in 1990 and 1992. The results obtained are summarized as follows: The direction of tidal current at the north enterance of Yeosu bay was southerly in ebb and northwesterly in flood without the distiction of the neap tide and the spring tide. In spring tide the maximum Velocity of the tidal current was 68 cm/sec in ebb and 66 cm/sec in flood. In neap tide the maximum velocity of the tidal current was 37 cm/sec in ebb and 35 cm/sec in flood. And so the direction of residual current was the south ward mainly and 21 cm/sec. The direction of tidal current at set net fishing grounds was southwesterly in ebb and westerly or northwesterly in flood. Regardless of the distinction of neap and spring. The maximum velocity of the current in spring tide was 50 cm/sec in ebb and 40 cm/sec in flood and that in neap was 28 cm/sec in ebb and 25 cm/sec in flood. In spring tide the speed vector along the major axis of semidiurnal tide component was three times as large as diurnal tide. In neap tide, however, the speed vector was about 50% less then that in spring tide, and the semidiurnal tide and diurnal tide were equal in the size of current ellipse and the direction of major axis. The sea area had a southwesterly residual current. 11 cm/sec in spring tide and 7 cm/sec in neap tide. According to the result of drogue tracking, the vicinity of set net fishing ground had a southerly residual current which formed in Yeosu Bay and a weak westerly residual current toward Dolsando from Namhedo. Therefore, set net fishing ground in coastal water of Yeosu was distributed in boundary of inner water which formed from Seamjin river and offshore water supplied from the vicinity of Sorido and Yochido.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.4
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• pp.386-395
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• 2017

For scientific research, a number of acoustic surveys using commercial echosounders equipped in fishing vessels were conducted throughout the world; however, few studies were performed in South Korea. Hence, this research is an preliminary study for presenting the application of a sounder from a fishing vessel. The fishing operations using a pair trawler (7 Cheonghae) was conducted in the Northwest-Western sea of Jeju Island from 20 to 23 April, 2016. Substantial impulse noises and attenuated signals were eliminated by the latest algorithms. Acoustic signals were grouped into the fish aggregations and long layer-like signals. The fish aggregations appeared between 30 and 60 m, and long layer-like signals showed the diurnal vertical migration. Energetic, morphological and positional properties of the fish aggregations and layer-like signals were described. The fish aggregations appeared mainly between sunrise and sunset; however layer-like signals tended to be presented regardless of time in consideration of the time series analysis. On the basis of the consignment sales, Scomberomorus niphonius, the target species of F/V 7 Cheonghae, was the highest catch with 4,280 kg (74.6%) and might have appeared in fish aggregations and layer forms.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.2
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• pp.75-84
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• 2018

The purpose of this study is that the low-cost mobile mapping system using INS (Inertial Navigation System) based on MEMS (Micro Electro Mechanical System) could decipher the interpretation of road facility with the accuracy of x, y 0.546m plane error. Even though the MMS (Mobile Mapping System) technology as a new measurement technology has been used vividly to set up geographic information by some world leading surveying equipment manufacturers, the domestic technology is still in its beginning stage. Several domestic institutes and companies tried to catch up the leading technology but they just produced prototypes which needs more stabilization. Through this thesis, we developed low-cost mobile mapping system installed with INS based on MEMS after time synchronizing sensors for MMS such as LiDAR (Light Detection And Ranging), CCD (Charge Coupled Device), GPS/INS (Global Positioning System / Inertial Navigation System) and DMI (Distance Measurement Instrument).

• Environmental and Resource Economics Review
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• v.19 no.4
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• pp.771-804
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• 2010

This paper estimates optimal production of fish stock using discrete time bio-economic model to make zero profits or to maximize economic profits with maintaining sustainable resource levels under an open access and a sole owner. Particularly, this study generates optimal yields and efforts of large purse seine fisheries which catch mackerel and jack mackerel by using the logistic growth function, Cobb-Douglas production function, fisheries cost and profit functions. As a result, optimal yields of mackerel and jack mackerel under ecological equilibrium of a sole owner were approximately 172,512 tons and 16,937 tons respectively. Also, optimal fishing efforts of mackerel and jack mackerel under the same situation were about 8,508 hauls and 4,915 hauls respectively. In conclusion, the paper suggests that the large purse seine should reduce fishing efforts and increase fish stock to generate higher net present value in optimally managed fishery than that of the present large purse seine.