• Title/Summary/Keyword: stock assessment

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Studies on the Fishery Biology of Pomfrets, Pampus spp. in the Korean Waters 6. Stock Assessment of Korean pomfret, Pampus echinogaster (한국근해 병어류의 자원생물학적 연구 6. 덕대의 자원해석과 관리)

  • KIM Yong Mun;KANG Yong Joo;PARK Byung Ha;LEE Dong Woo;LEE Joo Hee
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.22 no.5
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    • pp.306-316
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    • 1989
  • We examined the state of Korean pomfret(Pampus echinogaster) in Korean waters and considered the management strategy of the stock based on the theory yield Per recruit. It is not facile to discriminate Korean pomfret distributed in Korean waters from silver pomfret (p. argenteus) due to the similarities in their external morphologies. For this rea- son, Korean pomfret has been treated in silver pomfret in fisheries statistics of Korea. In this study, we asserted Korean pomfret from pomfrets caught commercially by the morphology, from which we recognized that Korean pomfret took $60\~70\%$ in catch(in weight) and that the smaller the body length, the higher the proportion of Korean pomfret. Parameters estimated for Korean pomfret were as follows: natural mortality(M) = 0.6, fishing mortality(F) =0.924(mean value for $1986\~1988$), age at recruit to fishery($t_r$) =0.19 yrs, age at first capture($t_c$) : 0.49 yrs, and the rate of recruit of age-0 fish to fishery(Q) = 0.29. The results obtained from the theory of yield per recruit indicated that the present state of stock was below the optimum level of exploitation and that the control of fishing intensity rarely had an effect on the increasing of yield. Accordingly, we conclude that proper management can be made by increasing the current age of 0.49 yrs at first capture to 1.5 yrs.

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Application of Remote Sensing Technology for Developing REDD+ Monitoring Systems (REDD+ 모니터링 시스템 구축을 위한 원격탐사기술의 활용방안)

  • Park, Taejin;Lee, Woo-Kyun;Jung, Raesun;Kim, Moon-Il;Kwon, Tae-Hyub
    • Journal of Korean Society of Forest Science
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    • v.100 no.3
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    • pp.315-326
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    • 2011
  • In recent years, domestic and international interests focus on climate change, and importance of forest as carbon sink have been also increased. Particularly REDD+ mechanism expanded from REDD (Reduced Emissions from Deforestation and Degradation) is expected to perform a new mechanism for reducing greenhouse gas in post 2012. To conduct this mechanism, countries which try to get a carbon credit have to certify effectiveness of their activities by MRV (Measuring, Reporting and Verification) system. This study analyzed the approaches for detecting land cover change and estimating carbon stock by remote sensing technology which is considered as the effective method to develop MRV system. The most appropriate remote sensing for detection of land cover change is optical medium resolution sensors and satellite SAR (Synthetic Aperture Radar) according to cost efficiency and uncertainty assessment. In case of estimating carbon stock, integration of low uncertainty techniques, airborne LiDAR (Light Detection and Ranging), SAR, and cost efficient techniques, optical medium resolution sensors and satellite SAR, could be more appropriate. However, due to absence of certificate authority, guideline, and standard of uncertainty, we should pay continuously our attention on international information flow and establish appropriate methods. Moreover, to apply monitoring system to developing countries, close collaboration and monitoring method reflected characteristics of each countries should be considered.

Comparison of Carbon Storage Based on Alternative Action by Land Use Planning (토지이용에 따른 대안별 탄소 저장량 비교)

  • Seulki Koo;Youngsoo Lee;Sangdon Lee
    • Journal of Environmental Impact Assessment
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    • v.32 no.6
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    • pp.377-388
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    • 2023
  • Carbon management is emerging as an important factor for global warming control, and land use change is considered one of the causes. To quantify the changes in carbon stocks due to development, this study attempted to calculate carbon storage by borrowing the formula of the InVEST Carbon Storage and Sequestration Model (InVEST Model). Before analyzing carbon stocks, a carbon pool was compiled based on previous studies in Korea. Then, we estimated the change in carbon stocks according to the development of Osong National Industrial Park (ONIP) and the application of alternatives. The analysis shows that 16,789.5 MgC will be emitted under Alternative 1 and 16,305.3 MgC under Alternative 2. These emissions account for 44.4% and 43.1% of the pre-project carbon stock, respectively, and shows that choosing Alternative 2 is advantageous for reducing carbon emissions. The difference is likely due to the difference in grassland area between Alternatives 1 and 2. Even if Alternative 2 is selected, efforts are needed to increase the carbon storage effect by managing the appropriate level of green cover in the grassland, creating multi-layered vegetation, and installing low-energy facilities. In addition, it is suggested to conserve wetlands that can be lost during the stream improvement process or to create artificial wetlands to increase carbon storage. The assessment of carbon storage using carbon pools by land cover can improve the objectivity of comparison and evaluation analysis results for land use plans in Environmental Impact Assessment and Strategic Environmental Impact Assessment. In addition, the carbon pool generated in this study is expected to be used as a basis for improving the accuracy of such analyses.

Age Structure and Biomass of the Icefish Pseudochaenichthys georgianus Norman (Channichthyidae) Between 1976 and 2009: a Possible Link to Climate Change

  • Traczyk, Ryszard;Meyer-Rochow, Victor Benno
    • Ocean and Polar Research
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    • v.41 no.4
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    • pp.233-250
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    • 2019
  • A re-assessment of the age structure of the population of the Antarctic icefish Pseudochaenichthys georgianus based on body length data covering the years 1976-2009 and including larvae and postlarvae collected in 1989 and 1990 allowed us to define age groups 0, I, and II as containing fish with respective body lengths of 6-9 cm, 15-27 cm and 27-39 cm. Age at maturity (first spawning) was found to occur in age group III at body lengths that have been falling from 50.1 cm in 1979 to 45.4 cm in 1992. Considering postlarvae together with adult fish, the v. Bertalanffy growth curve parameters were determined as L = 60.62 cm, k = 0.4, t0 = 0.25. Although the reasons for a maturity at shorter body lengths is not fully understood a host of environmental factors like increasing water temperatures and possibly changes in currents, interspecific competition, food availability, etc. are likely to be involved. Global warming (and not primarily overfishing) is likely to have been responsible for the disappearance of larger fish in the surface waters of South Georgia since 1977, for virtually all commercial fishing stopped in the early 1990s. On the other hand, the appearance of numerous younger spawning individuals suggests that larvae do survive in the colder deeper water below 200 m. The biomass of Ps. georgianus oscillates with a 4-year periodicity in contrast to that of the coexisting icefish Chaenocephalus aceratus: the former with a lower biomass in warm years and a higher one in cold years. The biomass of the third species of icefish in the region, i.e. Champsocephalus gunnari, also oscillates, but with a longer periodicity than that involved in the biology of the other two and its biomass increases in contrast to the other two species. The result is that the biomass all three species considered together is rather stable.

Assessment of seismic fragility curves for existing RC buildings in Algiers after the 2003 Boumerdes earthquake

  • Mehani, Youcef;Bechtoula, Hakim;Kibboua, Abderrahmane;Naili, Mounir
    • Structural Engineering and Mechanics
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    • v.46 no.6
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    • pp.791-808
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    • 2013
  • The main purpose of this paper is to develop seismic fragility curves for existing reinforced concrete, RC, buildings based on the post earthquake field survey and the seismic performance using capacity design. Existing RC buildings constitute approximately 65% of the total stock in Algiers. This type of buildings, RC, was widely used in the past and chosen as the structural type for the future construction program of more than 2 millions apartments all over Algeria. These buildings, suffered moderate to extensive damage after the 2003 Boumerdes earthquake, on May 21st. The determination of analytical seismic fragility curves for low-rise and mid-rise existing RC buildings was carried out based on the consistent and complete post earthquake survey after that event. The information on the damaged existing RC buildings was investigated and evaluated by experts. Thirty four (34) communes (districts) of fifty seven (57), the most populated and affected by earthquake damage were considered in this study. Utilizing the field observed damage data and the Japanese Seismic Index Methodology, based on the capacity design method. Seismic fragility curves were developed for those buildings with a large number data in order to get a statistically significant sample size. According to the construction period and the code design, four types of existing RC buildings were considered. Buildings designed with pre-code (very poor structural behavior before 1955), Buildings designed with low code (poor structural behavior, between 1955-1981), buildings designed with medium code (moderate structural behavior, between 1981-1999) and buildings designed with high code (good structural behavior, after 1999).

Fiber Analysis and Environmental Assessment of Recycled Waste paper for Eco-friendly Corrugated Box Manufacture (친환경 골판지 상자 제조를 위한 재활용 폐지 섬유의 물리적·환경적 특성 평가)

  • Park, Jung-Yoon;Lee, Tai-Ju;Kim, Hyoung-Jin;Kim, Jin-Mu
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.45 no.4
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    • pp.65-74
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    • 2013
  • In the manufacture of corrugated box, the fibrous raw materials are mainly consisted of recycled papers, such as KOCC(Korean Old Corrugated Container), kraft sack, and AOCC(American Old Corrugated Container). Among these recycled waste paper, the proportion of KOCC is relatively higher than others in fibrous raw materials. Generally, KOCC shows some poor fiber properties and contains hazardous heavy metal sources. Therefore, it is to evaluate the property of recycled paper sources for eco-friendly corrugated box manufacture. In this study, the physical and mechanical properties of 3 kinds of recycled fibers and their mixed stocks were analyzed. The environmental assessment was also evaluated by analyzing the 4 representative heavy metal contents and evaporation residues in waste papers. As the results, KOCC showed the poorest fiber qualities and had the highest heavy metal contents and evaporation residues among the recycled fibers. Finally, the mechanical strength properties were increased by decreasing KOCC proportion of mixed stock conditions. In addition, the heavy metal contents and evaporation residues were also decreased by increasing recycled AOCC and kraft sack proportion.

Assessment of Equity Market Responses on the Construction Project Awards (건설프로젝트 수주에 대한 시장의 평가)

  • Choi, Jong-Soo;Heo, Seong-Tae;Lee, Hee-Min
    • Journal of the Korea Institute of Building Construction
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    • v.10 no.1
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    • pp.221-228
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    • 2010
  • A construction firm's performance is largely attributable to performance in individual projects. In this regard, the awarding of an individual project has significant implications. However, project awards have received limited attention in the construction sector from amarket assessment perspective. This event study focuses on an analysis of market responses at the time of project awarding. A total of 252 samples wereselected through a rigorous sample screening processes. Performance was measured as cumulative abnormal return, which is traditionally adopted in event analysis. Research results indicated that the overall return is positive, and that the level isstatistically significant. Equity holders realized a higher return for projects awarded from the foreign countries compared to domestic projects. No relationship was observed between project size and the level of return. Other research findings and implications were discussed in detail from a management perspective.

Analysis of the Frequency , Criticality and Difficulty of Each Job Task Elements for the Validity of the Dietitian's Job Description (영양사 직무기술서 내용 타당성 검증을 위한 각 직무의 빈도 , 중요도 , 난이도 분석)

  • Mun, Hyeon-Gyeong;Lee, Ae-Rang;Lee, Yeong-Hui;Jang, Yeong-Ju
    • Journal of the Korean Dietetic Association
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    • v.7 no.1
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    • pp.105-116
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    • 2001
  • This study was conducted a part of the project developing the standards of national board test for the dietitian's licence. The purpose of this study was to verify the dietitian's job description. To do this the survey was carried out for the frequency, criticality and difficulty of each job description with 4 point scales. The subjects was 521 dietitians, who have been working over 3 years at their position. The results are following ; 1. The each duty, task and task elements are verified with survey results. 2. Duties with high frequency and criticality were menu management, purchasing, storage and stock management, operational management for cooking, system management for distribution and sanitation management. 3. Duties with middle frequency and high criticality were managing equipment and facility, food service management, human resources management and self-development. 4. Duties with low frequency and high criticality were nutritional assessment for life cycles, nutrition therapy, nutrition education and disease management. 5. For difficulty, food service area show lower than of nutrition service area.

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Seismic fragility curves of single storey RC precast structures by comparing different Italian codes

  • Beilic, Dumitru;Casotto, Chiara;Nascimbene, Roberto;Cicola, Daniele;Rodrigues, Daniela
    • Earthquakes and Structures
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    • v.12 no.3
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    • pp.359-374
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    • 2017
  • The seismic events in Northern Italy, May 2012, have revealed the seismic vulnerability of typical Italian precast industrial buildings. The aim of this paper is to present a seismic fragility model for Italian RC precast buildings, to be used in earthquake loss estimation and seismic risk assessment by comparing two building typologies and three different codes: D.M. 3-03-1975, D.M. 16-01-1996 and current Italian building code that has been released in 2008. Based on geometric characteristics and design procedure applied, ten different building classes were identified. A Monte Carlo simulation was performed for each building class in order to generate the building stock used for the development of fragility curves trough analytical method. The probabilistic distributions of geometry were mainly obtained from data collected from 650 field surveys, while the material properties were deduced from the code in place at the time of construction or from expert opinion. The structures were modelled in 2D frameworks; since the past seismic events have identified the beam-column connection as the weakest element of precast buildings, two different modelling solutions were adopted to develop fragility curves: a simple model with post processing required to detect connection collapse and an innovative modelling solution able to reproduce the real behaviour of the connection during the analysis. Fragility curves were derived using both nonlinear static and dynamic analysis.

Stock Assessment of Yellow Croacker for Korean Trawlers in The Yellow Sea and East China Sea (항해 및 동지나해에 있어서 기선저인망어업 대상 참조기의 자원량 해석)

  • 신상택
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.8 no.1
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    • pp.1-13
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    • 1972
  • Yellow croacker, Tseudociaena manchurica Jordan et Thompson in the Yellow Sea and East China Sea are subjected to be caught by trawl nets throughout the year. First indices of population size in every period 8re calculated. Considering present status of the yellow croacker fishery and ecology of the fish, mathematical models must have been established in order to determine catchability coefficient, natural m ortali ty, fishing mortality, recrui ting coefficient of the fish ing ground, and dispersion coefficienl from the fishing ground. The results an, summmarized as follows: Catchabil i ty coefficient $(C) = 2. 2628 {\times} 10^{-5}$ Natural mortality (M)=0.3293 Population for lhe first half season(July 1st to the following January 3lst) Initial population = 14, 621 $/\frac{M}{T}$ Recruitment =45, 597 $/\frac{M}{T}$ Natural mortality = 8, 660 $/\frac{M}{T}$ Final population =42, 970 $/\frac{M}{T}$ Population for the latter 1131f scason(February 1st to June 30th) Initial population = 69, 170 $/\frac{M}{T}$ Dispersion =51, 688 $/\frac{M}{T}$ Natural mortality = 6, 082 $/\frac{M}{T}$ Final population = 1, 802 $/\frac{M}{T}$.

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