• 한국농공학회논문집
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• 제64권4호
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• pp.55-64
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• 2022

The objectives of this study were to assess physical habitat suitability of fish species for different life cycle stages and to suggest appropriate ecological stream flows in a Bokha downstream reach. A dominant species of Zacco platypus was selected as the study fish of which three stages of spawning, juvenile and adult in life cycle were considered into assessment. The stream hydraulic environment was calibrated with HEC-RAS before the PHABSIM simulation. The hydraulics of flow velocity and depth were used to estimate Weighted Usable Area (WUA) by multiplying respective habitat suitability indices with stream area. Overall the WUAs tend to be great in gentle slopes with relatively shallow water depth regions. Maximum WUAs, ie, candidate for ecological flow rates were 1 m³/s, 7 m³/s and 8 m³/s for the respective spawning, juvenile and adult stages of Zacco platypus. Since the ecological flow rates for juvenile and adult stages appeared to be is greater than the abundant flow rate (3.67 m³/s) for the study reach, additional water supply may be needed but should be cautious to avoid the spawning period of Apr through May from the stream water management perspective.

• 환경영향평가
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• 제24권3호
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• pp.217-232
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• 2015

본 연구의 목적은 전주천의 환경특성과 이용자 모니터링을 통한 구간별 하천관리방안 모색에 있다. 전주천 생태하천 복원구간의 환경특성으로 상류는 전주한옥마을과 인접하고 매우 좋은 수질과 자연하천경관을 갖고 있으며, 중 하류는 수질상태가 양호하고 시설물이 집중되어 하천의 이용이 높은 구간이다. 설문을 통해 이용자특성, 이용행태, 시민참여, 중요도 우선순위, 중요도-만족도를 조사하였고, 설문응답 총 454부 중 무응답 완전제거 후 383부에 대한 인구 통계적 분석과 중요도-만족도 분석 (Importance-Satisfaction Analysis: ISA)을 수행하였다. 그 결과 상 중류는 60대 이상, 하류는 30~50대의 이용률이 높고, 10분 이내, 도보권 이용자들이 운동을 목적으로 '혼자', '계절과 관계없이', '매일' 혹은 '주 2~3회' 방문하는 것으로 나타났다. '생태체험 활동'과 '하천지킴이 참여'는 '경우에 따라 참여'가 세구간 평균 78%로 나타났다. 중요도 우선순위에서 상 하류는 '수질' > '녹지연결' > '산책로', 중류는 '수질 > '식물관리' > '산책로'로 나타나 '수질'이 가장 중요함을 알 수 있었다. ISA 결과, 전 구간 10개 항목의 만족도(3.00)가 중요도(4.02)보다 낮아 개선이 필요하며, '우선시정' 관리로 상류는 '식물 및 시설물관리', 중 하류는 '식물관리', 전체 구간은 '식물관리'(I-S: 4.13, 2.89)로 나타났다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.167-174
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• 2004

Several metalliferous and coal mines, including Myungjin, Seojin and Okdong located at the upper watershed of Okdong stream, were abandoned or closed since 1988 due to the mining industry promotion policy and thus disposed an enormous amount of mining wastes without a proper treatment facilities, resulting in water pollution in the downstream areas. AMD and waste effluents from the closed coal mines were very strongly acidic showing pH ranges of 2.7 to 4.5 and had a high level of total dissolved solid (TDS) showing the ranges of 1,030 to 1,947 mg/L. Also heavy metal concentrations in these samples such as Fe, Cu, Cd and anion such as sulfate were very high. These parameters of AMD and effluents were considered to be highly polluted as compared to those in the main stream area of the Okdong river and be major pollutants for water and soil in tile downstream area. Pollution indices of the surface water at the upper stream of Okdong river where AMD of the abandoned coal mines was flowed into main stream were in the ranges of 16.3 to 47.1. On the other hand, those at the mid stream where effluents from tailing dams and coal mines flowed into main stream were in tile ranges of 10.6 to 19.5. However, those at the lower stream were ranged from 10.6 to 14.9 These results indicated that mining wastes such as AMD and effluents from the closed mines were tile major source to water pollution at the Okdong stream areas.

• 한국환경과학회지
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• 제16권8호
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• pp.973-983
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• 2007

The eco-hydrologic effects of maintenance water supply on Oncheon stream are studied using hydrologic, hydraulic and ecologic models. SWMM (Storm Water Management Model) is used for long-term simulation of runoff quantity and water quality from Oncheon stream watershed. Using the output hydrologic variables from SWMM, HEC-RAS (River Analysis System) is then used to simulate the hydraulics of water flow through Oncheon stream channels. Such hydrologic, hydraulic and water quality output variables from SWMM and HEC-RAS are served as input data to execute PHABSIM (Physical Habitat Simulation) for the purpose of predicting the micro-habitat conditions in rivers as a function of stream flow and the relative suitability of those conditions to aquatic life. It is observed from the PHABSIM results that the weighted usable area for target fishes has the maximum value at $2m^3/s$ of instream flow. However, mid and down stream areas that have concrete river bed and covered region are unsuitable for fish habitat regardless of instream flow increment. The simulation results indicate that the simple maintenance water supply is limited in its effect to improve the ecological environment in Oncheon stream. Therefore, it is imperative to improve water quality and to recover habitat conditions simultaneously.

• 한국물환경학회지
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• 제22권5호
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• pp.796-804
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• 2006

The objective of this research was to develop ecological multi-metric models using natural fish assemblages for a diagnosis of current stream health condition, and apply the model to nationwide lotic ecosystems of the Geum River, the Youngsan River, and the Sumjin River. The ecological stream health model was based on the index of biological integrity (IBI), which was originally developed in North American streams by Karr (1981), and the Rapid Bioassessment Protocol (RBP), which was scientifically established by the US EPA (1999). The metric numbers and metric attributes were partially changed for the regional applications, so the scoring criteria was modified for the assessment. Overall, metric values, based on the IBI calculations, reflected conventional water quality characteristics, based on nutrient regime, and agreed with results of staticeco-toxicity tests. Some stations impaired in terms of stream health were identified by the IBI approach, and also major key stressors affecting the stream health were identified by additional evaluations of physical habitats. Our preliminary results suggested that biological integrity in stream ecosystems was largely disturbed by habitat degradation as well as chemical pollutions. This new approach would be used as a key tool for ecological restorations and species conservations in the degraded aquatic ecosystems in Korea and applied for elucidating major causes of ecological disturbances. Ultimately, this approach provides us an effective management strategy of stream ecosystems through establishments of ecological networks in various watersheds.

• 한국환경보건학회지
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• 제19권4호
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• pp.14-24
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• 1993

The present study was accomplished from October, 1992 to June, 1993 in order to examine the seasonal community structure of aquatic insects and the biological estimation of water quality by the aquatic insects of the Jungneung and Gokneung streams in the Mt. Bukhan. The obtained results are as follows: 1. The total taxa of aquatic insects appeared as 77 species, 45 genera, 28 families in 7 orders. 2. Seasonal occurrence species numbers showed the highest in the autumn of the Jungneung stream (19 species) and in the spring of the Gokneung stream (41 species). Seasonal occurrence individual numbers showed the highest in the summer of the Jungneung and Gokneung streams (5,901, 3,180 individuals) and the lowest in the autumn of Jungneung stream (612 individuals) and in the winter of the Gokneung stream (1,764 individuals). 3. Annual dominance indices showed 0.52 (stJ1)~1.00 (st.J3) range in the Jungneung stream, and 0.47 (st. G1)~0.76 (G2) range in the Gokneung stream. 4. Seasonal species diversity indices showed 0.00 (st J3, whole seasons)~3.12 (st.J1, Spring) range in the Jungneung stream and 0.69 (st. G2, summer) ~3.10 (st. G4, spring) in the Gokneung stream. 5. Biological saprobic system based on species diversity indices of aquatic insects appeared as oligosaprobic area: site J3, $\alpha$-mesosaprobic area: site J2, G2, G3 and $\beta$-mesosaprobic area: site J1, G1, G4.

• 생태와환경
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• 제50권4호
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• pp.403-410
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• 2017

본 연구는 2008년부터 2016년까지 1차부터 7차까지 총 12,873지점을 대상으로 하천차수별 어류분포를 조사하였다. 하천차수에 따른 피라미와 참갈겨니 개체군의 분포 양상에서 차이를 보였으며, 상관관계 분석 결과 두 개체군간 잠재적인 경쟁관계 가능성을 확인하였다. 두 개체군과 다른 공서 어류의 생태특성은 하천차수의 구배에 따라 중간종, 민감종, 내성종, 육식종, 초식종, 잡식종 등 뚜렷한 구배가 나타나는 반면, 충식종의 경우 뚜렷한 구배가 나타나지 않았다. 어류의 생태특성에 따르면, 피라미의 경우 중간종이면서 잡식종, 참갈겨니의 경우 민감종이면서 충식종으로 구분이 되는데, 두 개체군은 내성도 길드의 중간종과 민감종, 섭식 특성 길드의 잡식종과 충식종에서 유사한 상관관계의 변화를 보였지만, 두 개체군은 생태특성에 따른 각 기능군과 서로 다른 상관성의 차이를 보였다. 어류평가지수는 하천차수의 증가에 따라 감소하는 경향을 보였으며, 상관관계 분석 결과 두 개체군은 하천차수별 상관성의 차이를 보였지만, 1차에서 4차까지 유사한 상관관계의 변화를 보였으며, 5차부터 7차까지 차이를 보였다.

• 한국수자원학회논문집
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• 제46권11호
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• pp.1079-1088
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• 2013

지하수 양수정의 위치는 대수층내 지하수 유동과 하천-대수층의 상호작용에 영향을 미치므로 효과적인 지하수 개발 이용 및 하천수 관리를 위해서는 개별적인 지하수 관정의 양수 위치에 따른 하천수량 변화를 정량적으로 분석하는 과정이 선행되어야 한다. 따라서 본 연구에서는 경기도 이천에 위치한 신둔천 유역에 대해서 단일 관정으로부터의 지하수 양수가 인근 하천구간에 미치는 영향을 지표수-지하수 통합모형 SWAT-MODFLOW를 이용하여 모의, 분석하였다. 유역내에 존재하는 지하수 관정들 중 임의로 50개를 선별하고 각각의 단일 관정의 양수로 인한 인접 및 하류부 하도 구간의 하천수 감소에 미치는 영향을 평가하였고, 특히 양수로 인한 하천 영향 판별 지표로 많이 사용되고 있는 하천고갈인자 및 하천바닥인자의 적용성을 검토하였다. 각각의 단일 관정의 지하수 양수 전 후의 하천유량을 비교한 결과 양수량 대비 하천수 감소량은 작게는 20% 미만에서 크게는 90%가 넘는 등 지역 및 하천-관정 이격거리에 따라 큰 차이를 나타내었다. 하천고갈인자와 하천바닥인자 모두 하천수감소량과는 상관성이 높지 않아 양수로 인한 하천에 미치는 영향을 판정하는 절대적인 기준이 될 수는 없는 것으로 분석되었다. 하지만, 하천-관정 이격거리가 약 500 m 이내인 경우에는 하천바닥인자는 하천 영향정도를 평가하는 지표로 사용이 가능할 것으로 분석되었다.

• Journal of information and communication convergence engineering
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• 제12권4호
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• pp.237-245
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• 2014

In this study, software-based countermeasures against a side-channel cryptanalysis of the Rabbit stream cipher were developed using Moteiv's Tmote Sky, a popular wireless sensor mote based on the Berkeley TelosB, as the target platform. The countermeasures build upon previous work by improving mask generation, masking and hiding other components of the algorithm, and introducing a key refreshment scheme. Our contribution brings improvements to previous countermeasures making the implementation resistant to higher-order attacks. Four functional metrics, namely resiliency, robustness, resistance, and scalability, were used for the assessment. Finally, performance costs were measured using memory usage and execution time. In this work, it was demonstrated that although attacks can be feasibly carried out on unprotected systems, the proposed countermeasures can also be feasibly developed and deployed on resource-constrained devices, such as wireless sensors.

• International Journal of Computer Science & Network Security
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• 제23권9호
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• pp.157-161
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• 2023

Reliability is one of the computable quality features of the software. To assess the reliability the software reliability growth models(SRGMS) are used at different test times based on statistical learning models. In all situations, Tradational time-based SRGMS may not be enough, and such models cannot recognize errors in small and medium sized applications.Numerous traditional reliability measures are used to test software errors during application development and testing. In the software testing and maintenance phase, however, new errors are taken into consideration in real time in order to decide the reliability estimate. In this article, we suggest using the Weibull model as a computational approach to eradicate the problem of software reliability modeling. In the suggested model, a new distribution model is suggested to improve the reliability estimation method. We compute the model developed and stabilize its efficiency with other popular software reliability growth models from the research publication. Our assessment results show that the proposed Model is worthier to S-shaped Yamada, Generalized Poisson, NHPP.