• 한국환경복원기술학회지
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• 제18권6호
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• pp.215-226
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• 2015

This study introduced food waste into re-vegetation base materials for surface loss recovery of carry-away highway cut slope. The object of this study is to derive the mixing ratio of food waste by conducting a test installation, monitoring, analysis and evaluation for recovery of carry-away highway cut slope. The following items were investigated and analyzed each experimental zone to draw mixing ratio of re-vegetation base materials and food waste : the physical and chemical properties of the vegetation base materials, soil-hardness, soil-humidity, left out and the collapsed point, established number of trees, species richness of grass species and tree species, coverage, pest status, and invasion of disturbance species. The re-vegetation method was evaluated by each experiment zone which has different mixing ratio. As a result, experiment zone A was rated 45 points out of 60 rating points as the best re-vegetation method. However, this study result has been derived from one construction and short-term monitoring. In order to derive the suitable and dependable mixing ratio, conducting an objective re-vegetation method evaluation and long-term experiment and monitoring is required.

• 한국환경복원기술학회지
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• 제19권4호
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• pp.45-59
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• 2016

This study introduced wood waste into revegetation base materials for recovery of highway cut slope. The object of this study is to derive the mixing ratio of wood waste, kaoline and silica by conducting a test installation, monitoring, analysis and evaluation. The following items were investigated and analyzed each experimental zone to deduce the mixing ratio of wood waste, kaoline and silica on slope revegetation base materials: the physical and chemical properties of the vegetation base materials, soil-hardness, soil-humidity, collapse and eroded spots, established number of trees, existing species of grass and tree species, vegetation coverage ratio, pest status, and invasion of disturbance species. The revegetation method was evaluated in each experiment zone which had different mixing ratios. As a result, experiment zone C scored 47 points out of 60 as the best revegetation method. However, this result has been derived from just one construction and short-term monitoring. In order to derive the suitable and dependable mixing ratio, conducting an objective revegetation method evaluation and long-term experimenting and monitoring is required.

• 한국항행학회논문지
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• 제12권5호
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• pp.509-515
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• 2008

사용자의 요구에 대한 명확한 요구분석은 성공적인 소프트웨어 개발의 필수 요건이다. 그리하여, 개발될 소프트웨어 구성에 큰 영향용 준다. 기존의 많은 소프트웨어들이 인터넷의 급격한 발전과 함께 웹 기반으로 변화 되었다. 웹 애플리케이션이 복잡해지고 사용자의 요구가 증가되면서 많은 비용과 인력이 개발에 소요되고 있다. 그러나 아직까지 웹 애플리케이션에 대한 정확한 개발환경의 정의가 잘 되어있지 않다. 개발에 있어서도 사용자의 요구사항을 반영하지 못하여 사용자가 자유롭게 정보에 접근하는 기능의 설계가 어렵게 되었다. 본 논문에서는 소프트웨어 요구분석 프로세스를 수정하고, 요구사항을 분석하여 식별할 수 있는 방법을 제안하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1994년도 추계학술대회논문집; 한국종합전시장, 18 Nov. 1994
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• pp.165-169
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• 1994

외팔보의 진동문제를 외란에 대한 감도최소화 문제로 공식화하여 현재 많이 개발되어 있는 H$_{\infty}$ 제어기법의 해를 이용하여 접근하고, 이의 성능을 비교하기 위하여 H$_{2}$ 공간에서의 특수한 문제인 LQG를 다루었다. 작동기는 압전소자를 사용하였고, 실제 항공익 등의 문제와 일치를 꾀하기 위하여 기반가진 형태의 외란을 가하였다. 모의 실험이 수행되었으며, 제시된 제어기가 많은 상황에서 좋은 성능을 가진다는 것이 밝혀졌다.

• The Korean Journal of Ecology
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• 제23권2호
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• pp.83-88
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• 2000

When interpreting change over time in forest ecosystems, distinguishing the effects of forest succession from the effects of environmental stress can be difficult. The result may be a simplistic interpretation. citing a specific successional or environmental cause of forest change when both types may be occurring. We present two case studies of changes in the forest floor in northern hardwoods. First, the belief that 50% of soil organic matter is lost in the first 20 years after logging was based on a study comparing northern hardwood stands of different ages. We resampled a series of 13 such stands after an interval of 15 years, and found that the young stands were not, in fact. losing organic matter as rapidly as predicted from the original chronosequence study. The pattern of higher organic matter content in the forest floors of older stands compared to young stands could be equally well explained by changes in logging practices over the last century as by the aging of the stand. The observed pattern of forest floor organic matter as a function of stand age was previously interpreted as a successional pattern, ignoring changes in treatment history. In the second case study, observed losses of base cations from the forest floor were attributed to cation depletion caused by acid rain and declining calcium deposition. We found that young stands were gaining base cations in the forest floor; losses of base cations were restricted to older stands. Differences in litter chemistry in stands of different ages may explain some of the pattern in cation gains and losses. In this case, the contribution of successional processes to cation loss had been overlooked in favor of environmental stress as the dominant mechanism behind the observed changes. Studies of environmental stress use repeated measures over time. but often don't consider stand age as a factor. Studies of successional change often assume that environmental factors remain constant. We were able to consider both forest succession and external factors because we repeatedly sampled stands of different ages.

• Journal of Chest Surgery
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• 제16권2호
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• pp.213-220
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• 1983

Pulmonary function is the determinant of blood gas tension. However, Acid-Base disturbances can also alter partial pressures of oxygen and carbon dioxide in arterial blood. During respiratory acidosis $PO_2$ will be lowered and reverse changes will be produced during respiratory alkalosis. On the other hand, in metabolic acidosis $PO_2$ will be elevated and $PCO_2$ will be lowered by the respiratory compensation, and reverse response will be induced in metabolic alkalosis. Urinary gas tension has many influencing factors than arterial blood and difficult to estimate the tendency of its alterations. Urinary $PO_2$ and $PCO_2$ are not always identical level as venous blood. It is to be altered by blood gas tension, flow rate of urine, metabolic rate of kidney, and Acid-Base status of blood. Particularly countercurrent exchange of oxygen and carbon dioxide in the renal medulla will make larger alteration of gas tension than venous blood. After induction of Acid-Base disturbances [disturbances] arterial and urinary $PCO_2$, $PO_2$, urinary volume, and osmolarity were determined in dogs, and the relationships between arterial and urinary $PCO_2$ , $PO_2$ Acid-Base disturbances, urinary volume, and osmolarity were investigated. 1. During the acute Metabolic and Respiratory disturbances urinary pH did not respond on respiratory origin. However, there were immediate urinary response in pH on metabolic origin. 2. Urinary $PO_2$, $PCO_2$, did not always follow arterial or venous gas tension and Acid-Base disturbance. Urinary $PCO_2$, correlate well with the urinary volume. The larger the urinary volume, $PCO_2$ lowered to the venous level. The smaller the urinary volume, urinary $PCO_2$ tends to be higher. However urinary $PO_2$ did not have any particular correlation with urinary volume. 3. Correlation between urinary $PCO_2$ and $PO_2$ were inversely proportional to arterial blood. Differences of $PCO_2$ between arterial blood and urine also did not have any particular correlation with urinary volume. This may suggest that changes on blood gas tensions can influence on urinary $PCO_2$. 4. There were eminent clear inverse correlation between urinary $PCO_2$ and osmolar concentrations of urine. Above results strongly suggest that partial pressure of gas in urine primarily depend upon counter-current exchanges in renal medullary tissues.

• 소음진동
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• 제10권2호
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• pp.325-330
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• 2000

A dynamic absorber is used to protect the primary vibration system under the steady-state harmonic disturbance. In a number of cases it appears expedient to install several absorbers of smaller masses instead of one. This may be due to the need of distribute the absorber's response along the construction, restrictions on the absorber's installation. So, we studied characteristics of the primary vibration system for the optimal natural frequency ratio and the optimal damping ratio of serial multi-dynamic absorber. Also we obtained the optimum values of the serial multi-dynamic absorber parameters using computer simulation for the damped primary vibration system. In designing multi-dynamic absorber, we presented for the optimal natural frequency and the optimal damping ratio of multi-dynamic absorbers.

• 한국안전학회지
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• 제7권4호
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• pp.95-99
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• 1992

The attraction of using expert system in operator support systems for modern plant is that it offers a way of dealing with the problem of information overload that can occur during a severe disturbance at a modern industrial plant. During such a disturance the volume of information presented to operators may be such that they are unable to decide quickly what is important and what is not. Therefore, arriving at a correct diagnosis of the initialling fault may be delayed. An expert system operator sup-port system is a means of focusing attention on what really matters and cutting out the rest. This paper presents the development of prototype expert system which detect the fault part, machine, system and decide action priority. This prototype expert system has 6 sub- system which is Interface Manager, Decision Maker, Inference Engine, Knowledge base, Simulatio, and D.P System ( Diagnosis and predictor)

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1703_1704
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• 2009

Fuzzy neural ship controllers is used in ship steering control. It can make full use of the advantage of all kinds of intelligent algorithms. This provides an efficient way for this paper. An RBF neural network and GA optimization are employed in a fuzzy neural controller to deal with the nonlinearity, time varying and uncertain factors. Utilizing the designed network to substitute the conventional fuzzy inference, the rule base and membership functions can be auto-adjusted by GA optimization. The parameters of neural network can be decreased by using union-rule configuration in the hidden layer of the network. The ship control quality is effectively improved in case of appending additional sea state disturbance. The performance of controller is evaluated by the system simulation using simulink tools.

• Journal of Electrical Engineering and Technology
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• 제3권3호
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• pp.363-372
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• 2008

In this paper, knowledge-based approach using Support Vector Machines (SVMs) are used for estimating the coordinated zonal settings of a distance relay. The approach depends on the detailed simulation studies of apparent impedance loci as seen by distance relay during disturbance, considering various operating conditions including fault resistance. In a distance relay, the impedance loci given at the relay location is obtained from extensive transient stability studies. SVMs are used as a pattern classifier for obtaining distance relay co-ordination. The scheme utilizes the apparent impedance values observed during a fault as inputs. An improved performance with the use of SVMs, keeping the reach when faced with different fault conditions as well as system power flow changes, are illustrated with an equivalent 265 bus system of a practical Indian Western Grid.