• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.10a
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• pp.403-404
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• 1999

발전소, 공상, 지방자치단체 통 국내 대부분의 대기실 관리기관에서 활용할 수 있는 전산기가 개인용 컴퓨터(PC)인 점을 고려하여 위와 같은 여건의 기관들도 쉽게 현업 운영할 수 있도록 KRM 대기확산모델을 개발하였다. 또한, 위의 기관들이 대기오염 수치모델에 대한 전문 지식을 소유한 전문가를 확보하기 어려운 점을 고려하여 대기오염 관리와 Windows O/S에 관한 기본 지식만을 소유한 담당자도 시스템을 사용할 수 있도록 GUI(Graphical User Interface)기법을 활용, KRM 대기확산모델링 시스템을 개발하였다.(중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.10a
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• pp.163-167
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• 1999

컴퓨터가 일반화됨에 따라 대기질 관리 및 연구 분야에서 수치모델 이용이 보편화되고 있다. 현재 사용되는 대기오염 수치모델의 종류는 매우 다양하며, 구동에 필요한 전산시스템의 규모도 다양하다. 연구용 및 대형 모델들은 활용 분야가 넓고 신뢰도가 높은 반면 대형 전산시스템과 고도의 전문 인력을 요구한다. 그러나, 국내 대부분의 대기질 관련 기관의 사용 가능한 전산시스템과 담당 인력을 고려할 때 대형 모델의 사용이 일반화되기에는 한계가 있다.(중략)

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.3
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• pp.239-248
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• 2003

This paper was conducted as an attempt in order to construct the data bank of target strength for acoustic estimation of fish length in the coastal waters of Korea. The fish length dependence of acoustic target strength for 13 large yellow croakers (Pseudosciaena crocea) at 75 kHz was investigated and the prediction of the target strength by using the Kirchhoff-Ray Mode model (KRM model) was compared with target strength measurements. The results obtained are summarized as follows; 1. In the averaged target strength pattern for 13 large yellow croakers the maximum target strength was -35.13 dB at $-13.35^{\circ}$ on a tilted angle. 2. The relationship between fork length(L, cm) and averaged target strength(TS, dB) was expressed as follows; TS=23. 76log (L) -73.45 (r=0.47) TS=20log(L) -67.35 From this result, the conversion coefficient was -73.45 dB and 6.1 dB lower than the coefficient -67.35 dB where the value of the slope of the regression equation is forced to be 20. 3. Averaged target strength and a length conversion coefficient derived from a target strength histogram for 13 large yellow croakers of mean length 25.59 cm were -41.23 dB, -69.72 dB, respectively. 4. In the range of $$2;{\ll} L (fish length /{\lambda}(wave length);{\ll}40$$, the prediction of the averaged target strength by the KRM model increased gradually with the increasing of $L/{\lambda}$ and was lower than the measured target strength.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.2
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• pp.209-217
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• 2020

The purpose of this study was to compare the model-predicted and experimentally measured target strength (TS) of golden cuttlefish Sepia esculenta cuttlebones. Ultrasonic signals used to estimate frequency-dependent TS and the speed of sound in cuttlebones were measured by pulse-echo and through-transmission techniques, using a chirp sonar system and an ultrasonic pulser/receiver system under controlled laboratory conditions. The model appeared to slightly underestimate the predicted TS values in the frequency range of 100-160 kHz. However, there was good agreement between the predicted and measured TS values in the frequency range of 160-200 kHz. The significant similarity between the model-predicted and experimentally measured TS values supports the use of the Kirchhoff-ray mode (KRM) model for acoustic scattering analysis of cuttlebones. Accordingly, we concluded that the KRM model can be used as a tool to evaluate the frequency-dependent variability of TS due to changes in golden cuttlefish swimming depth.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.46 no.2
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• pp.157-163
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• 2010

The indirect target strength (TS) estimation method which uses the Kirchhoff ray mode model (KRM model) was discussed to apply for a biomass estimation in the water of mixed species. TS of 25 live scorpion fishes for 120kHz were measured by a tethered method and of others dominant 5 species in the marine ranching ground of Jeju coastal water including a scorpion fish were also estimated by KRM model. The measurement TS of scorpion fish well agreed with the theoretical values and the standard formula of scorpion fish was estimated as $TS_{120kHz}=20Log\;(L)-72.9$ ($r^2=0.67$). TScm values estimated on trial to each sample of dominant 5 species were from -69.3dB to -75.1dB at 120kHz and they were in the general range of swimbladdered fish. It was clarified that TS by KRM model can be used to estimate fish biomass estimation by increasing a sample number and is more effective under the condition that there is rare TS information for inhabiting species in mixed-species area.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.58 no.1
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• pp.32-38
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• 2022

In this study, Target strength for multi-frequency (38 kHz, 70 kHz, 120 kHz and 200 kHz) of chub mackerel (Scomber japonicus) was estimated using by the KRM model. The body shape of the Chub mackerel was described by an X-ray system and the body length of 20 individuals ranged from 16 cm to 28 cm. The swimbladder tilt angle ranged between -8 and -14°, the maximum TS value according to the swimming angle of chub mackerel was -33.0 dB at -11°. The averaged TScm according to fork length was -66.02 dB at 38 kHz, -66.50 dB at 70 kHz, -66.00 dB at 120 kHz and -67.35 dB at 200kHz, respectively.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.2
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• pp.152-159
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• 2017

Rockfish was a commercially important fish specie in marine ranching areas in Korea. To estimate density and biomass of rockfish using acoustic method, target strength (TS) information is required on the species. This study measured TS dependence on tilt angle and size on 14 live rockfish individuals at 38, 70, and, 120 kHz by ex-situ measurement (tethered method) and acoustic scattering model (Krichhoff ray mode, KRM). The swimbladdered angle ranged from 18 to $30^{\circ}$ ($mean{\pm}s.d.=26{\pm}4^{\circ}$). The mean TS for all individuals was highest -35.9 dB of tilt angle $-17^{\circ}$ at 38 kHz, -35.4 dB of tilt angle $-25^{\circ}$ at 70 kHz, and -34.9 dB of tilt angle $-22^{\circ}$ at 120 kHz. The ex-situ TS-total length (TL, cm) relationships were $TS_{38kHz}=20log_{10}(TL)-67.1$, $TS_{70kHz}=20log_{10}(TL)-68.6$, and $TS_{120kHz}=20log_{10}(TL)-69.9$, respectively. The model TS-total length (TL, cm) relationships were $TS_{38kHz}=20log_{10}(TL)-66.4$, $TS_{70kHz}=20log_{10}(TL)-67.0$, $TS_{120kHz}=20log_{10}(TL)-67.0$. The two measurements between the ex-situ TS and KRM model for TS-tilt angle and fish size were found to be significantly correlated.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.3
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• pp.424-431
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• 2015

This study was focused on acoustic scattering characteristics of jack mackerel (Trachurus japonicus) at frequency 38, 70, and 120 kHz by Kirchhoff-ray mode (KRM) model. The body length (BL) of 16 individuals ranged in 12.2~22.0 cm ($mean{\pm}S.D.$: $17.8{\pm}3.2cm$) and the swimbladder length ranged in 4.2~8.6 cm ($mean{\pm}S.D.$: $6.6{\pm}1.6cm$) and the swimbladder cross section ranged in $1.7{\sim}6.6cm^2$ ($mean{\pm}S.D.$: $3.8{\pm}1.6cm^2$). This result shows that results correlate well between the BL and the length and cross section of swimbladder. The swimbladder angle ranged in $7{\sim}12^{\circ}$ and the maximum TS values ranged in $-16{\sim}-5^{\circ}$ at tilt angle. The averaged TS-to-BL relationship were $TS_{38kHz}=20{\log}_{10}BL-65.33$ ($R^2=0.66$), $TS_{70kHz}=20{\log}_{10}BL-65.90$ ($R^2=0.67$), and $TS_{120kHz}=20{\log}_{10}BL-66.65$ ($R^2=0.65$). These results can be used fundamental data in order to estimate distribution and biomass of jack mackerel by using hydro-acoustic method.

• Journal of the Korean Society for Library and Information Science
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• v.43 no.2
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• pp.277-298
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• 2009

In order to utilize the operational metadata retrieval system which is based on the semantic association between the research outcomes of the Korean Research Memory (KRM), the systematic integration of the metadata of the research outcomes with the term data registry (DR) was required. This study presents the ontology which can be used effectively to support the KRM. It includes the concept modeling of the knowledge structure of research outcomes, information retrieval service modeling that applies an analytical approach to researchers' needs in conjunction with the term DR, and also some technical and administrative suggestions for future system management.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.48 no.4
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• pp.487-494
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• 2012

Acoustical backscattering characteristics of Japanese anchovy can be estimated by Kirchhoffray mode model (KRM model) due to estimate exact body and swim-bladder shape of the fish, the samples were rapidly frozen by dry-ice and alcohol. X-ray photos for ventral and lateral direction for 6 samples were taken and the 3D coordinates of the body swim-bladder were estimated by digitizing from the photos. The angles between the axis of body and swim-bladder were about $9^{\circ}$ at 38kHz and $7^{\circ}$ at 120kHz, 200kHz. General formula of TS and BL estimated were < $TS_{38kHz}$ >=20logBL-67.3, < $TS_{120kHz}$ >=20logBL-66.6, < $TS_{200kHz}$ >=20logBL-67.0. As a result, we confirmed KRM model is very useful to estimate TS (Target Strength) for design of experiment and it also can be applied to estimate the abundance of Japanese anchovy distributed by 2 frequency difference method in the survey area.