• Journal of Korea Water Resources Association
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• v.40 no.12
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• pp.1007-1014
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• 2007

Recently, existing river improvement methods for flood control purpose have changed into nature friendly river improvement methods and the efforts to improve the river environment including river restoration have been made, and close-to-nature river improvement and nature friendly river restoration are actively conducted all over the country. In the present situation where various revetment methods are used after the introduction of the concept of close-to-nature river improvement, the environmental characteristics of rivers need to be considered to apply more suitable revetment methods. Therefore, as a precedent study for the development of revetment evaluation techniques and methods for close-to-nature river improvement, the present study suggested evaluation techniques using detailed survey items through field survey. Evaluation items of hydraulic stability consist of mode of streamline, stream bed gradient, flow velocity and tractive force ratio and those of environmental efficiency consist of revetment of vegetation, state of river water, land use of the terrace land on the river, vegetation and materials of the terrace land on the river. Each item was graded with the point 1 through 5. Hydraulic stability and environmental efficiency was evaluated by the points which were averaged in each items. As the result of the application of the proposed evaluation technique, it was found that a number of existing revetments excessively focus on hydraulic stability with little consideration about environmental term. It is expected that the proposed technique in the present study can be used as a base for providing guidelines to construct the design and construction of revetments in the future.

• Polymer(Korea)
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• v.25 no.1
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• pp.142-150
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• 2001

Until now rubber industry field has used organic solvent base adhesive, there was always existed a fire risk, variety of quality and harmfulness of human body. To solve this problem we were developed a new adhesive that was maked by raw materials of hydrocarbon series which has the properties of nonvolatile and high flash point. Because of this new adhesive has the properties of nonvolatile and non-harmfulness to the human body, we expected to solve the problems of a fire hazard and the pollution of the environmental. Instead of the rubber binder that is used to a present adhesive, the new idea is adopted in a new type of adhesive. Nonvolatile solvent penetrated to the rubber surface and caused the swelling in rubber surface and as a result of this action, it has the self-adhesive power. In comparision with the present adhesive a new type of adhesive remarkably improved the maintenance time of adhesion and the durability of this adhesive showed similar aspect. Because it did not exhibit a drop of physical properties of rubber which was caused by swelling effect, we estimate that new type adhesive are very stable and not reacted to several rubber additives. While present adhesive appear the crack at cutting surface of curing rubber that caused by gas, new type adhesive not exist these crack.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.11_12
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• pp.692-704
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• 2005

With the improvement of computer hardware, GPUs(Graphics Processor Units) have tremendous memory bandwidth and computation power. This leads GPUs to use in general purpose computation. Especially, GPU implementation of compute-intensive physics based simulations is actively studied. In the solution of differential equations which are base of physics simulations, tridiagonal matrix systems occur repeatedly by finite-difference approximation. From the point of view of physics based simulations, fast solution of tridiagonal matrix system is important research field. We propose a fast GPU implementation for the solution of tridiagonal matrix systems. In this paper, we implement the cyclic reduction(also known as odd-even reduction) algorithm which is a popular choice for vector processors. We obtained a considerable performance improvement for solving tridiagonal matrix systems over Thomas method and conjugate gradient method. Thomas method is well known as a method for solving tridiagonal matrix systems on CPU and conjugate gradient method has shown good results on GPU. We experimented our proposed method by applying it to heat conduction, advection-diffusion, and shallow water simulations. The results of these simulations have shown a remarkable performance of over 35 frame-per-second on the 1024x1024 grid.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6905-6916
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• 2015

The primary purpose of this paper is to find out the environmental regulation in our global society with complex system concept. After the industrial revolution, there were working toward solving various problems while there has been an industry advancement. But, there are various issues that a simple international trade or economic technologic levels were not solved. The evolution of technologies through complex systemic thought are not accidental issues. These issues build and provide a predictable technology innovation that system was emergent a new order. With complex systemic thought, the earth that was facing environmental problems was in the phrase edge of chose. These conditions played the trigger role for the solving various problems in environmental regulations but they don't get along well together. There were no causal relationship between structural elements. This paper describes an emergence of new order through these interactions in environmental regulation. These environmental regulations make desperate efforts not only public sectors but also private or/and firms that make an emergence of new order with the critical point reached. Also, we provide the understanding base an environmental regulation with new order for uncertainty.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.1
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• pp.40-49
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• 2004

This work carried out to define the characteristic of Cymbidium kanran habitat at Mt. Halla in Jejudo, Korea from the ecological point of view including geological and topographical features, air and soil temperature, relative humidity, fluctuations of light intensity, habitat vegetation, distribution altitude, area limit, and etc. And another goal of this study consider the conservation counterplan of the cymbidium habitat. Natural distribution areas of the cymbidium were observed more abundantly on the well drained south and east-facing slopes. Soil acidity was ranged from pH 4.1 to 5.3, and electric conductivity was ranged from 176.4 to 299.9 us/cm (average 215.3 us/cm). Base-saturation percentage of the habitat soil was below 50%, bulk density 0.42g/$cm^2$, particle density 2.05g/$cm^2$, humus content 26%, total nitrogen 0.82%, available phosphate 4.2 mg/kg, exchangeable potassium 0.63 Cmol/kg, calcium 0.44 Cmol/kg and magnesium 0.67 Cmol/kg. Annual mean air temperature was $15.4^{\circ}C$, however, air temperature was ranged $11.7{\sim}18.2^{\circ}C$ in spring, $21.2{\sim}23.8^{\circ}C$ in summer, $12.8{\sim}22.0^{\circ}C$ in fall and $5.5{\sim}7.8^{\circ}C$ in winter season. Annual mean soil temperature at depth of 10cm was $13.2^{\circ}C$ And minimum value was recorded $4.7^{\circ}C$ on January, and maximum value $22.5^{\circ}C$ on August. Relative humidity was ranged 90.8~94.7% in summer, 80.8~91.5% in fall and 77.6~84.2% in winter season. Minimum value was 56.5% on December, and maximum value was 100% on July and August. Light intensities were ranged from 400 to 1,800 lux at the greater part of Cymbidium kanran sites in Jejudo. Summer regarded as an lower light intensities was recorded to be range of 500~600 lux; however, autumn and winter were shown higher light regimes ranged from 3,500 to 3,800 lux. Therefore, one must be suprised that the cymbidium grow at the light condition of 6 lux (minimum) or 10,000 lux (maximum). Tree species keeping higher frequency rate and density were Eurya japonica, Camellia japonica, Castanopsis cuspidata, Carpinus laxiflora and Pinus densiflora. Number of trees growing in a 5${\times}$5m quardrat was 35 as an average, and proportion of evergreen versus deciduous was 5:1. Distribution altitude of the orchid habitat was ranged from 120m (low) to 840m (high) from sea level on the south facing slope of Mt. Halla, and was ranged eastern borderline of Gujwaup, Bukjejugun to western boundaries of Jungmundong, Seogwipo city. For the stable conservation of Cymbidium kanran habitat, sunlight regimes must be increased more by means of cutting trees or twigs in the site.

• Journal of Oriental Neuropsychiatry
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• v.7 no.1
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• pp.1-13
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• 1996

1. Out of 21 examples on a clinical base Alzheimer type dementia were 8 examples(38%), 11 vascular types(52%), 1 Alzheimer and vascular mixed type and rest 1 was secondary dementia type(NPH).2. Between the genders, there were 5 males and 3 females for Alzheimer types, 6 males and 5 females for the vascular types, 1 male for Alzheimer and vascular mixed type, and 1 female for secondary dementia type(NPH).3. For the degrees of Alzheimer type dementia there were 2 mild dementia, 4 moderate dementia, and 2 severe dementia. 4. Among the Alzheimer types 2 mild dementia were almost recovered back to normal in approximately 2 months, 2of 4 moderate dementia became significantly better in approximately 2 months and recovered to almost normal state in 3 to 5 months. The rest 2 have been under treatment for 3 months, but showed a little improvement. Out of 2 severe dementia examples, one showed a little improvement even if it has been under treatment over 2 years. The other example did not show any improvement, but dementia did not proceed any more.5. Among the 11 vascular examples, 7 recovered in 2 to 3 months, 1 in 5 months, 2 recovered in a year, and the treatment was stopped arbitrary for the last one.6 In the case of Alzheimer and vascular mixed type dementia, even the moderate dementia did not show any apparent result in 6 months.7. For NPHI (Normal Pressure Hydrocephalus), there was an improvement on dementia in 2 months after the treatment, but gait disturbance and urinary incontinence did not show any noticeable difference. As a conclusion, almost all the Alzheimer and vascular type patients recovered, but the treatment periods varied depending on the types of the dementia and the degree of seriousness, especially in the case of the severe Alzheimer patients, the treatment oniy suppression the progression of the dementia. The most important aspect from clinical point of view was even if almost all the patients were almost completely cired, they need to keep being cured for a long period of time. The method with respect to Four Constitutions is thought of the most desirable.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.16 no.1
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• pp.27-40
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• 1998

This paper addresses the suitability of GPS positioning technology to monitoring deformation and movement of structures. The first part of the study is an empirical quantitative study of the repeatability of GPS observations and the second part is a performance evaluation of kinematic GPS, which requires only a few minutes per a point, for monitoring deformation of an engineering structure. On the test network for monitoring of a earth am, four observations have been conducted repeatedly on different seasons and water levels. The reference network was observed in static mode, and monitoring points were observed respectively in rapid-static mode as well as in kinematic mode in each epoch and then the results were compared with those obtained by conventional surveying techniques. The repeatability of baseline vectors to better than average 7 mm in three dimensions was achieved in base line observations between reference points and also the unclosure of reference networks showed the range of 4 ppm to 27 ppm. Compared with conventional surveying techniques, the kinematic approach showed the differences of 3∼4 m in slope distances which were observed from reference points to monitoring points, and showed the differences of 4∼8 m in height. It was ascertained that the kinematic GPS technology provides an efficient alternative to deformation monitoring by conventional means which are capable of detecting movements in the order of 5 mm.

• The Korean Journal of Nuclear Medicine
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• v.29 no.1
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• pp.22-30
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• 1995

To predict preoperatively the safety of permanent occlusion of an internal carotid artery with $^{99m}Tc$-HMPAO brain single photon emission computed tomography(SPECT) from an objective point of view, Twenty-four patients underwent balloon test occlusion (BTO) of the internal carotid arteries because of neck and skull base tumors. The authors assessed the uptake of both middle cerebral artery territories before and during BTO with $^{99m}Tc$-HMPAO brain SPECT using semiquantitative analysis method and compared the results with other factors(neurologic examination, arterial stump pressure and electroenceph-alogram). Nineteen patients had not experienced neurological deteriorating or any problem during BTO. Their comparative uptakes of the middle cerebral artery territories were 95 to 101% of the pre-BTO state. The remaining five patients showed severe neurologic symptoms such as transient hemiplegia and unconsciousness. Their comparative uptake of the middle cerebral artery territories were 77 to 85% of the pre-BTO state, and were well matched with other factors. $^{99m}Tc$-HMPAO brain SPECT before and during BTO seems to be a simple and objective method for prediction of permanent neurologic deficits when the comparative uptake of middle cerebral artery territories during BTO is lower than 85% of that before BTO.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.2
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• pp.105-112
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• 2018

To determine the position of receiver, the GPS (Global Positioning System) uses position information of satellites and pseudo ranges based on signals. These are reflected by surrounding structures and multipath errors occur. This paper proposes a method for multipath error reduction using digital images to enhance the accuracy. The goal of the study is to calculate the shielding environment of receiver using image processing and apply it to GPS positioning. The proposed method, firstly, performs a preprocessing to reduce the effect of noise on images. Next, it uses hough transform to detect the outline of building roofs and determines mask angles and permissible azimuth range. Then, it classifies the satellites according to the condition using the image processing results. Finally, base on point positioning, it computes the receiver position by applying a weight model that assigns different weights to the classified satellites. We confirmed that the RMSE (Root Mean Square Error) was reduced by 2.29m in the horizontal direction and by 15.62m in the vertical direction. This paper showed the potential for the hybrid of GPS positioning and image processing technology.

• Journal of Engineering Education Research
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• v.10 no.4
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• pp.78-92
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• 2007

This study presents how the engineering ethics instructional modules have been developed based on Korean culture and how they are implemented into the existing engineering curricula at Sungkyunkwan University. The engineering ethics instructional modules were designed to be taught by engineering faculty members who did not have any teaching experience in ethics. As a result, it was determined that the engineering ethics instructional modules should include a detailed instructor lesson plan and all supporting resources such as slides (Power Point base), and handouts, or assessment units (pre- and post-test). Two 75 minute modules developed in this study consist of the diverse instructional activities for various student group sizes. In order to improve students' interests and classroom attention, various visual and audio resources such as famous movies, cartoons, and poems were included in the instructional resources. In addition, a number of case studies which might happen in the students' daily lives were chosen. The resulting ethical module No. 1 has been instructed in the existing engineering classes during the 1st semester in 2007. Overall, the students reported positive impressions of the modules and the faculty members also reported favorable perceptions of the modules. Also, team based activities encouraged students to participate in constructing the event trees, which are a basic analysis tool for ethics case studies. The results of this study will provide a guideline of implementing engineering ethics into the engineering curricula to other engineering programs and schools.