• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.6A
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• pp.589-599
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• 2004

Most models assume the complete debugging environments by requiring a complete software correction in quantitative evaluation of software reliability. But, in many case, new faults are involved in debugging works, for complete software correction is impossible. In this paper, software growth model is proposed about incomplete debugging environments by considering the possibility of new faults involvements, and software faults occurrence status are also mentioned about NHPP by considering software faults under software operation environments and native faults owing to the randomly involved faults in operation before test. While, effective quantitative measurements are derived in software reliability evaluation, applied results are suggested by using actual data, and fitnesswith existing models are also compared and analyzed.

• Electronics and Telecommunications Trends
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• v.18 no.5 s.83
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• pp.63-72
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• 2003

소프트웨어의 신뢰성을 정량적으로 평가하는 데 있어서 소프트웨어 개발 프로세스의 시험단계나 사용자의 운용단계에 처한 동적 환경상태에서 소프트웨어 고장발생기능 현상을 기술한 소프트웨어 신뢰도성장모델을 많이 제안하고 있다. 대다수의 모델이 발생된 소프트웨어 고장의 발생원인에 대한 완전한 수정을 요구하는 완전 디버깅 환경을 가정하고 있다. 그러나 실제 개발자가 디버깅 작업을 수행할 때 완전한 수정이 불가능하기 때문이다. 다시 말해서 여러 소프트웨어 개발자가 경험한 이러한 디버깅 작업을 행하는 경우에는 결함을 제거하는 데 한계가 있기 때문에 수정 작업시 새로운 결함이 삽입되는 경우가 많다. 즉, 결함 수정은 불완전 환경에 처한다. 본 논문에서는 결함 수정시 신규 결함의 삽입 가능성을 고려하고 불완전 디버깅 환경에 대한 소프트웨어 신뢰도 성장모델을 제안한다. 소프트웨어 동작 환경 하에서 발생된 소프트웨어 고장과 시험 전 소프트웨어 내의 고유 결함에 의한 고장과 동작중에 랜덤하게 삽입된 결함에 의해 발생되는 고장 등 2종류의 결함을 고려하여 비동차 포아송과정(NHPP)에 의한 소프트웨어 고장발생 현상을 기술한다. 또한 소프트웨어 신뢰성 평가에 유용한 정량적인 척도를 도출하고 실측 데이터를 이용하여 적용한 결과를 제시하고 기존의 모델과의 적합성을 비교, 분석한다.

• Monthly Duck's Village
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• s.68
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• pp.48-56
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• 2009

현대와 같이 산업사회로 발달되기 이전의 자연생태계는 행복하였다. 청정한 태양 빛 아래 맑은 공기, 물, 흙과 나무가 어우러진 자연의 환경에서 엄연한 먹이사슬질서 속에서 살아 왔었는데, 인구증가와 산업사회로 발전하면서 대량수요가 요구되면서 그들은 점차 행복한 삶의 터전이 없어지고, 강제로 억제시킨 극도의 열악한 집단사육환경에 적응하면서 살아갈 수밖에 없게 되면서 먹이사슬에서 부작용과 역기능이 발생되기 시작하였다. 집단사육장환경을 획기적으로 개선해야 된다. 태양빛이 완전 차단되고 밀폐된 공간에서 집단사육시키고 있는 닭, 오리, 돼지가 정상적으로 생장할 수 있도록 적어도 자연환경에 가까운 밝고 청정한 환경으로 개선시켜야 된다. 사육동물들이 정상적으로 생장할 수 있도록 자연환경과 버금가는 생태환경으로 개선시켜 주어야만 오리들이 건강하게 성장하고 면역력이 증강되어 조류인플루엔자와 같이 원인불명의 질병에 감염되지 않을 것이다. 현실적으로 모든 실내 생태계의 성장을 활성화시키면서 면역력을 증강시킬 수 있는 생명에너지 빛(Bioenergetic Rays)을 방사하는 차세대 조명기술로 집단사육장의 실내를 획기적으로 밝게 하고, 실내의 탁한 공기가 신선한 외부공기로 충분히 순환이 될 수 있도록 반 밀폐구조로 개조해야 한다. 그리고 한 마리 당 활동공간을 넓혀 주어야 한다.

• Korean Journal of Environment and Ecology
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• v.30 no.6
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• pp.970-976
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• 2016

Determining age structure of the population of an endangered species is critical because it could provide basic information about population dynamics. In this study, we assessed the possibility if the growth lines on dorsal scutes of the national monument as well as endangered Reeves' turtle (Mauremys reevesii) can reliably estimate actual ages of the 100 turtles of which actual ages were known and have been housed in Seoul Zoo. We counted the number of growth lines on the first four dorsal scutes and the first left and right lateral scutes of each turtle and compared those with their known actual ages. Ages estimated by the growth lines were overestimated at between 1 and 5 actual ages, but underestimated at between 6 and 9 actual ages, indicating that age estimation using growth lines is only partially applicable at actual ages of less than 6 years old. In addition, using length and width of turtle's dorsal plates, we produced growth curves with equations to estimate actual ages of females combined with juveniles, but its application to estimate actual ages was not reliably possible because all subject turtles which used were at relatively young ages. In conclusion, when estimating actual ages of Reeves' turtles using the number of growth lines on the dorsal scutes, it is recommend to use minimum values at less than 6 lines, but use maximum values at more than 7 lines. As the first study which estimated actual ages of a turtle species using growth lines on the dorsal scutes in Korea, our results could be useful to estimate ages of the endangered Reeve's turtles in the field although its application might be limited.

• Journal of Internet Computing and Services
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• v.24 no.1
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• pp.61-69
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• 2023

Recently, as the fishery resources are depleted, expectations for productivity improvement by 'rearing fishery' in land farms are greatly rising. In the case of land farms, unlike ocean environments, it is easy to control and manage environmental and breeding factors, and has the advantage of being able to adjust production according to the production plan. On the other hand, unlike in the natural environment, there is a disadvantage in that operation costs may significantly increase due to the artificial management for fish growth. Therefore, profit maximization can be pursued by efficiently operating the farm in accordance with the planned target shipment. In order to operate such an efficient farm and nurture fish, an accurate growth prediction model according to the target fish species is absolutely required. Most of the growth prediction models are mainly numerical results based on statistical analysis using farm data. In this paper, we present a growth prediction model from a stochastic point of view to overcome the difficulties in securing data and the difficulty in providing quantitative expected values for inaccuracies that existing growth prediction models from a statistical point of view may have. For a stochastic approach, modeling is performed by introducing a Gaussian process regression method based on water temperature, which is the most important factor in positive growth. From the corresponding results, it is expected that it will be able to provide reference values for more efficient farm operation by simultaneously providing the average value of the predicted growth value at a specific point in time and the confidence interval for that value.

• Korean Journal of Environmental Biology
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• v.30 no.3
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• pp.272-279
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• 2012

This was the second study on the ecological characteristics of the epiphytes on seagrass leaf. The objective of this study was to understand the variation of epiphytes on seagrass leaf depending on the change of physico-chemical factors such as salinity, nutrients, and etc. This study showed the four results. 1) The eelgrass growth was influenced by water temperature, suggesting the positive correlation between eelgrass growth and water temperature. 2) The epiphytes growth on seagrass leaves did not show the correlation with water temperature, but negatively correlated with salinity. 3) The eelgrass growth decreased when the concentraion of nitrogen increased. 4) However, loads of epiphytes increased when the concentration of total nitogen (TN), nitrate ($NO_3^-$), and nitrite ($NO_2^-$) were high. This increase of epiphytes growth could be suggested in the cause-effect pathway of nutrient enrichment leading to seagrasses loss.

• Journal of Environmental Policy
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• v.10 no.4
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• pp.3-37
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• 2011

This paper investigates the existence of the environmental Kuznets curve (EKC) for carbon dioxide $CO_2$ emissions and its causal relationships with economic growth and openness by using time series data (1971-2006) from China (an emerging market), Korea (a newly industrialized country), and Japan (a developed country). The sample countries span a whole range of development stages from industrialized to newly industrialized and emerging market economies. The environmental consequences according to openness and economic growth do not show uniform results across the countries. Depending on the national characteristics, the estimated EKC show different temporal patterns. China shows an N-shaped curve while Japan has a U-shaped curve. Such dissimilarities are also found in the relationship between $CO_2$ emissions and openness. In the case of Korea, and Japan it represents an inverted U-shaped curve while China shows a U-shaped curve. We also analyze the dynamic relationships between the variables by adopting a vector auto regression or vector error correction model. These models through the impulse response functions allow for analysis of the causal variable's influence on the dynamic response of emission variables, and it adopts a variance decomposition to explain the magnitude of the forecast error variance determined by the shocks to each of the causal variables over time. Results show evidence of large heterogeneity among the countries and variables impacts.

• Environmental and Resource Economics Review
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• v.25 no.1
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• pp.61-87
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• 2016

Germany has carried out its environment friendly energy policy to prevent $CO_2$ emission that affects directly to the global warming phenomenon. Based on this direction, it has performed a sustainable development strategy through the R & D activities in environment and energy technologies. Accordingly, the core elements of German energy and sustainable development policies are renewable energy, ecological energy tax, and emission trading system. In particular, Germany has supported to develop renewable energy resources that prevents from consuming fossil energy resources. At the same time, it has set the ecological energy tax and initiated the emission trading system in order to support the renewable energy policy continuously. This paper analyze whether or not it is possible to generate an economic growth and a sustainable development while using renewable energy resources based on the renewable energy policy that minimize the negative effects on the environment. For that, the paper adopts Germany as a model country. In fact, it is possible to achieve the economic growth and the sustainable development if a nation can substitute increasing energy consumption for the economic growth to renewable energy resources that does not affect to the environment negatively. This model is the German energy policy and sustainable development strategy, and it is the purpose of the paper to prove it logically.

• Environmental engineer
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• v.18 s.195
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• pp.22-27
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• 2002

전국의 많은 환경관리인들은 주어진 책무를 다하기 위해 오늘도 많은 수고를 아끼지 않고 있다. 그러나 대부분의 경우 환경기술인들은 열악한 여건하에서 일을 해야 하기 때문에 많은 고생을 하고 있는 것이 현실이다. 최고경영자의 관심부족, 인적물적자원의 부족, 관계자들의 이해부족 등의 여건 속에서 일을 해야 되는 것은 물론 환경전문가로서 더욱 발전하여야 함에도 불구하고 공부할 수 있는 여건 등이 미비하여 훌륭한 환경전문가로서의 성장과 위상의 제고보다는 환경현장

• Ecology and Resilient Infrastructure
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• v.9 no.3
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• pp.183-193
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• 2022

The growth inhibitory effect of Microcystis aeruginosa according to the ultrasonic irradiation time was evaluated using a large algae sample volume (10 L) for various ultrasonic irradiation times (0.5, 1, 1.5, 2, 2.5 and 3 hr) at a laboratory scale. Based on the analysis of Chl-a and cell number of M. aerginosa, algae growth inhibition was observed with the decrease in Chl-a and cell number in all experimental groups after the ultrasonic irradiation. For the experimental group (T_B, T_C, T_D) with an ultrasonic irradiation time of less than 2 hours, rapid regrowth of algae was observed after growth inhibition, but the experimental group (T_E, T_F, T_G) with an irradiation time of more than 2 hours successfully inhibited algal growth lasting one or two more days. Based on the comparison of the recovery time to initial cell number the experimental group (T_B, T_C, T_D) took less than 20 days whereas the experimental group (T_E, T_F, T_G) took about 30 days. Correspondingly, the experimental group showed a high first order decay rate (𝜅) in proportion to the ultrasonic irradiation time during the growth inhibition period. Additionally, the specific growth rates (𝜇) during regrowth in the experimental group with irradiation time of more than 2 hours were relatively low compared to those in the experimental group with less than 2 hours. Therefore, ultrasonic irradiation for more than 2 hours is required for long-term (30 days) inhibition of algal growth in stagnant waters. However, the appropriate ultrasonic irradiation time for algae growth inhibition should be determined according to various field conditions such as the volume of stagnant water, water depth, flow rate, algae concentration, etc. Finally, damages to the algal cell surface and cell membrane were clearly observed, and both destruction and disturbance of gas vesicles of M. aeruginosa in the experimental group were discovered, indicating the growth inhibitory effect of Microcystis aeruginosa according to the ultrasonic irradiation time was confirmed.