• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.43 no.4
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• pp.310-319
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• 2007

To investigate the catches of squid jigging fishery, a series of fishing experiments was conducted in the high seas of the Northwest Pacific($40^{\circ}-43^{\circ}N$, $150^{\circ}-155^{\circ}E$) during the period of 1 August to 22 October 2005 by commercial fishing vessel. The number of 142 test fishing was carried out in the Northwest Pacific during 83days. The total catch were 47,524kg as 4 squid species and CPUE was $8.9kg/line{\cdot}day$. CPUE showed high values in the frontal zone during the survey. Main squid species caught from the experimental fishing were the neon flying squid, Ommastrephes bartrami(96.8%) and the boreopacific gonate squid, Gonatopsis borealis(3.2%). Dorsal mantle length of the neon flying squid were increased by the time and increasing of the hook size. Loss rate of the neon flying squid in the water showed the highest values in 28.2% compare to the others. And the loss rate of the front roller and in the air were 1.1% and 1.0%, respectively.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.33 no.2
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• pp.90-96
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• 1997

Until now the research was usually related in the fishing basket for crab charybdis japonica, concentrated one's effort to modification on the construction, shape, number of entrance of fishing basket etc.. But there's not make good used to the basically habit, shelter behavior of crab. etc., and was not fundamentally modified to the ability attracting the crab on net fishing basket. In this paper, first of all investigated to the behavior of crab in water tank and then two types modification fishing baskets could the increasing to ability attracting of crab on fishing basket were designed from the result obtained in this experiment and compared with modificated net fishing basket by Kim.Go(1987.1990) at a field and tank experiment. The results obtained are summarized as follows : 1. Being the fishing baskets had dropped in the tank bottom, the touched rate and reacted rate of crab according the elapsed time agree with to experiment of Kim.Go(1987.1990)in the mainly. however, in case of plate type tangle net, the touched rate of crab increased for a short time and then decreased and the reacted rate increased in a hurry to show a maximum and then was established. 2. The beginning catch time of crab was shortest in the plate type tangle net than the any fishing baskets because it's immediately entangled if the crab was touched only a part of body on net and latest in the net fishing basket. 3. A distance of between the touched rate and the reacted rate curve were the most short, wide in the plate type tangle net. therefore, the ability attracting of crab was excellent than the any fishing baskets and in case of pipe type fishing baskets, between the 150mm and 250mm seemed not difference and showed a tendency to increasing against the net fishing baskets. 4. Pipe type fishing baskets seemed to become a good shelting place for the crab because it showed a tendency to stagnate at the inside in that. 5. The mean catch per pot of crab among the net fishing basket, pipe type fishing baskets, plate type tangle net were highest in the pipe type fishing baskets than the net fishing basket and lowest plate type tangle net. Therefore it showed to difference against the tank experiment.

• Journal of Computing Science and Engineering
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• v.2 no.1
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• pp.1-25
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• 2008

Spoken dialog tasks incur many errors including speech recognition errors, understanding errors, and even dialog management errors. These errors create a big gap between the user's intention and the system's understanding, which eventually results in a misinterpretation. To fill in the gap, people in human-to-human dialogs try to clarify the major causes of the misunderstanding to selectively correct them. This paper presents a method of clarification techniques to human-to-machine spoken dialog systems. We viewed the clarification dialog as a two-step problem-Belief confirmation and Clarification strategy establishment. To confirm the belief, we organized the clarification process into three systematic phases. In the belief confirmation phase, we consider the overall dialog system's processes including speech recognition, language understanding and semantic slot and value pairs for clarification dialog management. A clarification expert is developed for establishing clarification dialog strategy. In addition, we proposed a new design of plugging clarification dialog module in a given expert based dialog system. The experiment results demonstrate that the error verifiers effectively catch the word and utterance-level semantic errors and the clarification experts actually increase the dialog success rate and the dialog efficiency.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.4
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• pp.397-402
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• 2011

We surveyed the bycatch and discard of the shrimp-pot fishery in Hokkaido, Japan, three times during the major fishing period in September 2005. The surveyed catches were analyzed to separate bycatch, discard, and landings. To analyze bycatch and discard, we randomly selected 2 shrimp pots from each of 7 sets, for a total of 14 pots per survey. The total bycatch and discards from the rest of the shrimp pots were also analyzed in each survey. The total catch averaged 12 species. Coonstripe and pink shrimp catches averaged 74.7 kg/haul and 12.7 kg/haul, respectively. The weight of the bycatch averaged 33.4 kg/haul. The bycatch consisted mainly of snail fishes(5.1%), brittle stars(5.0%), and short-spined sea urchins(4.1%). Our analysis showed that the ratio of discard was 0.38, the rate of the discard was 27.4%, and the discard per unit effort was 33.4 kg/haul. The Hokkaido shrimp-pot fishermen discarded all of the bycatch except shrimps. Hence, the weight of the bycatch was equal to the weight of the discard. Our results comprise preliminary data that can be used to find ways to reduce bycatch and discard in the shrimp-pot fishery.

• Ocean and Polar Research
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• v.28 no.4
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• pp.439-449
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• 2006

This study was aimed at measuring the fishing capacity of Powered Anchovy Drag Net Fisheries (PADNF) in Korea using Peak-to-Peak(PTP) and Data Envelopment Analysis(DEA) methods recommended by FAO. In the analysis, both fishing capacities of total PADNF and individual PADNF vessels were measured with time series data and cross sectional data, respectively. In addition, the results of the DEA measurement were analyzed in order to determine reduction levels of fishing capacity. In case of total PADNF, the results by rn and DEA methods showed a similar rate of capacity utilization (79%), indicating the capacity was not utilized enough. In addition, the sensitivity analysis suggested that the number of vessels should be reduced by 20%, and the gross tonnage and the horse power should be reduced by 20% and 21%, respectively if the current catch is to stay at the 2004 level. The DEA results on individual PADNF vessels indicated the capacity utilization was 75% on average, showing some differences in capacity utilization among vessels (31%-100%). The results of the study would be useful for measuring production efficiency in PADNF. They would also provide good policy information for efficient use of resources and capacity reduction levels, which are useful far vessel buyback programs of coastal and offshore fisheries.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.4 no.1
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• pp.1-6
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• 1971

In order to study the catching efficiency of shrimp trawl equipped with electrodes around the net mouth and stimulant devices attached to the ground rope, an experimental operation was carried out at Oma-Island Shrimp Farm from October 3rd to November 5th, 1970. Many studies have been made on the shrimp trawl with electric stimulant devices, but few can be found for detailed scientific catching methods. Electric power consumption was so excessive that electric stimulant devices could not be developed for commercial purposes. As a first step toward the successive operations of the electric stimulant devices in the field, it is necessary to study fundamental principles, such as electric current, voltage, electric potential, potential difference, electric field and suitable pulse. The behaviour response of the common shrimp, Penaeus japonicus BATE to moving nets and electric stimulant devices were reported in the preceding papers based on the water tank experiments (Ko and Kim, 1970). Through comparative fishing tests the rate of catching efficiency during daylight time was confirmed to be from 89 to 96 per cent of the night catch efficiency, and with 30 V. 1.5 A. electric power was sufficent for practical sea operation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.4
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• pp.344-348
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• 2006

The ecological characteristics and stock biomass of the Shiba shrimp, Metapenaeus joyneri, in Korean waters were determined, using fishery data from the Ministry of Maritime Affairs and Fisheries (MOMAF) and available length frequency data. The instantaneous coefficient of total mortality (Z) of M. joyneri was estimated to be 4.191year, and the annual survival rate (S) was 0.015. The estimated instantaneous coefficient of fishing mortality (F) for recent years was calculated to be 1.94/year. The age at first capture of M. joyneri was 0.71 years. Based on these parameters, the annual biomass of the M. joyneri stock was estimated using a biomass-based cohort analysis and data on the annual catch in weight at age for 1993-2004 in Korean waters. During the study period, the biomass of the shrimp peaked in 1994 at about 9,082 metric tons. Subsequently, it decreased to 500 metric tons in 1998.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.5
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• pp.490-495
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• 2015

As flying robots are becoming popular, there are increased needs to use themforsuch purposes as parcel delivery, serving in restaurants, and stage performances. To control flying robots such as quad copters, localization is essential. In order to properly position flying robots, many techniques are in development, including IR (infra-red)-based systemswhich catch markers on a flying robot in order that it can position itself. However, this technique demonstrates only short coverage. Furthermore, localization from inertial sensors diverges as time passes. For this reason, this paper suggests a TWR (two-way ranging) based positioning technique. Despite the weaknesses in currently available TWR system, this paper suggests a self-positioning and outlier detection technique in order to provide reliable position information with a faster update rate. The self-positioning system sends a shorter message which reduces wireless traffic. By detecting and removing outlier measurements, a positioning result with better accuracy is acquired. Finally, this paper shows that the suggesting system detects outlierssequentially from less than half the number of anchors in localization system according to the degree of outlier in measurement and the noise level. By performing an outlier algorithm, better positioning accuracy is acquired as shown in the experimental result.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.28 no.4
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• pp.360-370
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• 1992

In order to analyse the mesh selectivity for the trawl net, the fishing experiment was carried out by the training ship Saebada belonging to the National Fisheries University, in the Southern Korea Sea and the East China Sea from June 1991 to August 1992. The trawl net used in the experiment has the trouser type of cod-end with cover net and the mesh selectivity in the cod-end part. In this report, the species of fishes caught and the catch rate for them in accordance with different mesh sizes were analysed, and the result obtained are summarized as follows: 1) 145 species of aquatic animals were caught in totally 138 times of trawl operations. 2) The number of species mostly not to escape are 28, 22, 19, 16 and 11 respectively, in each opening mesh size, 51.2mm, 70.2mm, 77.6mm, 88.0mm and 111.3mm of cod-end. 3) In view that the use of the opening mesh size above 54mm in cod-end of trawl net in Korea, it is necessary to device a counterplan against the overfishing, for the 22 species of aquatic animals mostly not to escape in the cod-end of the large mesh sizes more than 70.2mm.

• 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.