• Title/Summary/Keyword: stock assessment

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Genetic stock identification of Chum salmon in the Pacific Rim (북태평양 서식 연어의 계군 분석)

  • Yoon, Moongeun;Abe, Syuiti;Jeong, Hee-Je
    • Proceedings of KOSOMES biannual meeting
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    • 2017.04a
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    • pp.82-82
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    • 2017
  • Chum salmon, Oncorhynchus keta, has received considerable attention in recent years for population genetic studies due to its broad geographic distribution and high commercial importance in North Pacific fisheries. The Bering Sea and North Pacific Ocean provide major feeding habitats for various salmon stocks originating from Japan, Russia and North America. Chum salmon are a dominant pelagic fish in the Bering Sea during summer and their numbers fall when they moved in coastal areas to spawn. Population genetic data for chum salmon that can serve as a baseline for stock identification studies are scarce. In this review, we describe recently developed molecular markers and discuss their use in the study of genetic population structure of chum salmon in the Pacific Rim. In addition, we review previous genetic studies focused on the assessment of stock compositions in mixed chum salmon aggregations in the Bering Sea and North Pacific Ocean.

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Length-based stock assessment of the pacific yellowtail emperor in the Southern Sulawesi, Indonesia

  • I Nyoman Suyasa;Alifah Fitam Rakhma Sari;Siska Agustina;Rian Prasetia;Ratna Suharti;Toni Ruchimat;Budy Wiryawan;Irfan Yulianto
    • Fisheries and Aquatic Sciences
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    • v.26 no.3
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    • pp.216-223
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    • 2023
  • Pacific yellowtail emperor, Lethrinus atkinsoni Seale, 1910, is one of the most targeted reef fish species in Southern Sulawesi, Indonesia. Therefore, assessing its stock is important to understand the condition of the population, providing valuable inputs for sustainable fisheries management in the area. Here we assess the stock condition of L. atkinsoni in Southern Sulawesi, Indonesia, using the length-based spawning potential ratio model. A total of 4,887 individuals were collected from commercially small-scale fishers from January to October 2022. The total length, sex, and gonad maturity of the individuals were examined. We observed that the fish length ranged from 10.5 to 39.5 cm, with an average length of 23.3 cm. The sex ratio was equal (1:1.2) between male and female individuals. Length at first maturity and length at first capture were 23.4 and 19.6 cm, respectively. In addition, we observed a growth coefficient of 0.45/year, with an asymptotic length of 41.14 cm and natural mortality of 0.6/year. Based on these life history parameters, we observed the spawning potential ratio (SPR) value of 12%, indicating an unsustainable fishery level (SPR of < 30%). Further concerns related to the sustainability of the species and strategy to rebuild stock of the L. atkinsoni in Southern Sulawesi are of utmost importance.

Estimation of Carbon Stock and Annual CO2 Uptake of Four Species at the Sejong National Arboretum - Pinus densiflora, Metasequoia glyptostroboides, Aesculus turbinata, Chionanthus retusus - (국립세종수목원 교목 4종의 탄소 저장량 및 연간 이산화탄소 흡수량 평가 - 소나무, 메타세쿼이아, 칠엽수, 이팝나무를 대상으로 -)

  • Hak Koo KIm;Yong Sik Hong;Yun Kyung Lim;I Seul Yun;Ki Seok Do;Chan Hyung Jung;Chi Mun Lee;Hoi Eun Roh;Sin Koo Kang;Chan-Beom Kim
    • Journal of Environmental Impact Assessment
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    • v.32 no.1
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    • pp.41-48
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    • 2023
  • This study was conducted to confirm the possibility of a new carbon stock in the Sejong National Arboretum, a major urban greenspace in Sejong-si. This study involved field and ground surveys of 1,336 trees, including 794 Pinus densiflora trees with a diameter at breast height (DBH) of above 5.5cm, which are the most planted in the Sejong National Arboretum, Chionanthus retusus 154 trees planted, Metasequoia glyptostroboides 216 trees, and Aesculus turbinata 172 trees as street trees. Measurements were performed from April to November. Based on the results of the survey, the carbon storage and annual carbon stock were calculated using the annual carbon stock estimation equation used in the forest carbon offset projects. As a result of comparing the carbon stock of the 12cm diameter class, which is the most distributed of four major trees, it was found in the order of C. retusus (0.0136tC/tree), P. densiflora (0.0126tC/tree), M. glyptostroboides (0.0092tC/tree), and A. turbinata (0.0076tC/tree). In addition, the field survey measurement data compared with terrestrial LiDAR measurement data for 20 trees showed a difference of 10.0cm in tree height and 1.7cm in diameter at breast height (p<0.05). In the future, additional carbon stock and annual uptake of other species planted in the arboretum are expected to promote the carbon uptake effect of the arboretum and contribute to the achievement of the national NDC. In the long term, it is also necessary to develop the carbon uptake factor of trees and shrubs mainly used to calculate the exact carbon uptake amount of trees mainly used in urban forests and gardens.

The analysis of TSI procedure in the ERTMS/ETCS (ERTMS/ETCS의 TSI 절차에 관한 분석)

  • Lee, Sang-Hyeok;Kim, Min-Seok;Jung, Dae-Young;Ko, Young-Hwan;Lee, Jong-Woo
    • Proceedings of the KSR Conference
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    • 2011.05a
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    • pp.125-131
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    • 2011
  • TSI(Technical Specification for Interoperability) is the highest technical specification in the Europe Railway and is composed by assessment items and essential requirements included by safety, reliability, availability, health, environment protection and technical compatibility. It is used on the research and development in the next generation railway technical. Currently, TSI procedures have been asked to bid for high speed rail business in Europe and Brazil. Also, all the railway systems such as infrastructure, signaling, electric and rolling stock system corresponding with standard of TSI procedures are exported and imported. Recently, Safety Critical System which has been studied on future railway R&D business in Korea is the state of the art train control system. And it is needed for system assessment of TSI procedures before system test and operation. In this paper, basic research is performed for analyzing TSI procedures suitable for the state of the art train control system in Korean railway.

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A Study on New Measurement of Derailment Coefficient for Rolling Stocks (철도차량의 새로운 탈선계수 측정방법에 관한 연구)

  • Hong, Yong-Ki;You, Won-Hee;Lee, Hi-Sung
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.306-312
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    • 2007
  • The running safety of rolling stock is assessed by derailment coefficient. It requires lots of preparatory time, expenditure and high measurement technique to measure derailment coefficient. If derailment coefficient could be measured when track or vehicle is maintained, safety will be improved. The measurement and assessment of running safety is necessary for safety especially for the vehicles newly developed and started service. Therefore measurement of derailment coefficient is most important thing to secure running safety. In this paper, we examined new assessment method which could estimate derailment coefficient by measuring vibration acceleration and displacement of vehicle operating at actual track irrespective of time and place. The new method could be used effectively as a mean confirming running safety.

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Schemes for the Environmentally Sound and Sustainable Development of Groundwater Resources (지하수자원의 환경적으로 지속가능한 개발 방안)

  • Hong, Sang-Pyo;Kim, Jung-Wuk
    • Journal of Environmental Impact Assessment
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    • v.5 no.2
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    • pp.49-57
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    • 1996
  • On the basis of sustainable long-term water resources planning, the development of ground water resources should be interlocked with the surface water development In considering the intertemporal equity, overpumping of groundwater may diminish or eliminate the groundwater resources stock of post-generations. Regulatory landuse zoning for groundwater resources recharge area is indispensable measures to prevent groundwater pollution. Adequate treatment of polluted water from various sources such as municipal sewage, industrial wastewater, landfill site leachate, and abandoned boring wells, is also necessary for groundwater protection. To preserve groundwater resources as common property goods, groundwater use tax should be imposed upon the large scale groundwater use. Finally, the establishment of groundwater development license system is recommended to achieve the social optimal production and to avoid external diseconomy.

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Stock assessment of starry flounder, Platichthys stellatus and olive flounder, Paralichthys olivaceus in the Uljin marine ranching area, Korea (울진 바다목장 강도다리 (Platichthys stellatus)와 넙치 (Paralichthys olivaceus)의 자원평가)

  • Yoon, Sang-Chul;Lee, Sung-Il;Yang, Jae-Hyeong;Yoon, Byoung-Sun;Kim, Jong-Bin;Cha, Hyung-Kee
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.50 no.4
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    • pp.583-594
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    • 2014
  • This study was performed to estimate biomass and provide management guidance through population ecological characteristics, including growth parameters, instantaneous coefficients of natural and fishing mortalities, and age at first capture of the starry flounder, Platichthys stellatus and olive flounder, Paralichthys olivaceus of Korea. For describing growth of this species, a von Bertalanffy growth model was adopted. The von Bertalanffy growth parameters estimated from a non-linear regression for starry flounder were $L_{{\infty}}=48.25cm$, K=0.16/yr, and $t_0=-1.48$, respectively and those for olive flounder were $L_{{\infty}}=86.46cm$, K=0.26/yr, and $t_0=-0.29$, respectively. Biomass of Platichthys stellatus was estimated by direct biomass estimation method was 2.6 M/T, that was estimated by indirect method was 13.4 M/Tt. Those of Paralichthys olivaceus were estimated as 10.1 M/T, 19.3 M/T, respectively. An yield per recruit analysis showed that the current yield per recruit on Platichthys stellatus was about 48.2 g with F=0.646/yr and the age at first capture ($t_c$) 1.35yr, that on Paralichthys olivaceus was about 167.6 g with F=1.121/yr and the age at first capture ($t_c$) 1yr.

Seismic risk investigation for reinforced concrete buildings in Antalya, Turkey

  • Kepenek, Engin;Korkmaz, Kasim A.;Gencel, Ziya
    • Computers and Concrete
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    • v.26 no.3
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    • pp.203-211
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    • 2020
  • Turkey is located in one of the most seismically active regions of in Europe. The majority of the population living in big cities are at high seismic risk due to insufficient structural resistance of the existing buildings. Such a seismic risk brings the need for a comprehensive seismic evaluation based on the risk analysis in Turkey. Determining the seismic resistance level of existing building stock against the earthquakes is the first step to reduce the damages in a possible earthquake. Recently in January 2020, the Elazig earthquake brought the importance of the issue again in the public. However, the excessive amount of building stock, labor, and resource problems made the implementation phase almost impossible and revealed the necessity to carry out alternative studies on this issue. This study aims for a detailed investigation of residential buildings in Antalya, Turkey. The approach proposed here can be considered an improved state of building survey methods previously identified in Turkey's Design Code. Antalya, Turkey's fifth most populous city, with a population over 2.5 Million, was investigated as divided into sub-regions to understand the vulnerability, and a threshold value found for the study area. In this study, 26,610 reinforced concrete buildings between 1 to 7 stories in Antalya were examined by using the rapid visual assessment method. A specific threshold value for the city of Antalya was determined with the second level examination and statistical methods carried out in the determined sub-region. With the micro zonation process, regions below the threshold value are defined as the priority areas that need to be examined in detail. The developed methodology can be easily calibrated for application in other cities and can be used to determine new threshold values for those cities.

Performance Assessment of a Temperature Control Unit used in a Lifecycle Testing System for LED Headlamps on Locomotives (철도차량용 LED전조등의 수명시험용 온도제어부의 성능평가)

  • Ohn, Jung-Ghun;Jeong, Ki-Seok;Chung, Jong-Duk
    • Journal of the Korean Society for Railway
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    • v.19 no.1
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    • pp.46-53
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    • 2016
  • LED light sources have been known to have a long life and good energy efficiency compared to traditional light sources. Recently, headlamps using LED light sources have ensured the forward visibility and safe operation of high-speed rolling stock. However, assessing the lifespan of LED headlamps based on real test data is not easy because it depends on the multiple stress factors such as a fixed driving current, junction temperature, vibration and so on. Generally, LED headlamps have failed before their advertised life span mainly due to temperature. Thus, the performance assessment of a temperature control unit should be done before a life cycle test of LED headlamps. This study attempted to develop a prototype temperature control module for a lifecycle test system using a commercial LED headlight and verified the system through experiments.

Spawning Period and Estimated Recreational Catch of Amphioctopus fangsiao in the Coastal Waters of Jeollanam-do, Korea (전라남도 연안에 서식하는 주꾸미(Amphioctopus fangsiao)의 산란시기와 유어낚시 어획실태)

  • Moon, Seong Yong;Kim, Heeyong;Lee, Mi Hee;Jung, Kyung Mi;Kim, Maeng Jin
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.55 no.1
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    • pp.61-66
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    • 2022
  • Amphioctopus fangsiao is a crucial fishery stock located off Korea's western and southern coasts. In this study, we present data on the spawning period and estimated recreational catch of A. fangsiao in the coastal waters of Jeollanam-do, South Korea. The overall sex ratio was estimated to be 1:1.13 (female: male); in females and males, the gonadosomatic index ranged from 1.22 to 12.14 and 0.17 to 3.44, respectively. The breeding season lasted from December to May, with spawning peaks observed between March and May. Furthermore, the estimated total annual recreational catch of A. fangsiao was 185,085 kg, with November recording the highest recreational catch. A. fangsiao catch per unit effort (CPUE) ranged from 3 to 302.4 kg per vessel d-1. Therefore, these findings underscore the need for additional monitoring, as any further assessment of A. fangsiao stock necessitates an understanding of recreational catch assessment and fishing efforts in Jeollanam- do's coastal waters.