• Economic and Environmental Geology
• /
• v.28 no.6
• /
• pp.579-585
• /
• 1995

The Samkwang mine is Cretaceous gold-silver-bearing deposits located in the western part of the Ogcheon belt The ore deposits have been emplaced within granite gneiss of the Precambrian age. The Au-Ag deposits are hydrothermal-vein type, characterized by arsenic-, gold- and silver-bearing sulphides, in addition to the principal ore-forming sulphides arsenopyrite, galena, sphalerite, chalcopyrite, pyrite and pyrrhotite. Their proven reserves are 355,000 MT, and grades are 8.4 g Au/t and 13.6 g Ag/t. On the basis of their structural characters, the Au-Ag-bearing quartz veins are classified into three types of ore veins; (1) The Main vein shows $N40^{\circ}-80^{\circ}E$ strike and $55^{\circ}-90^{\circ}SE$ dip, (2) the Sangban vein shows E-W strike and $30^{\circ}-40^{\circ}S$ dip, and (3) the Gukseong vein has $N25^{\circ}-40^{\circ}W$strike and $65^{\circ}-80^{\circ}SW$ dip. The emplacements of the ore veins are closely related to the minimum stress axis $({\sigma}_3)$ during the strike-slip movement of the study area. The ore-bearing veins filled with extension fractures during strike-slip movements were sequentially emplaced as follows: I) When ${\sigma}_1$ operates obliquely to NE-series discontinous surface, the Main fault zone $(F_1)$ developes. 2) During the same time, extension fractures ($T_1$ Gukseong veins) take place. 3) When the fault progress continuously, the existing $T_1$, may be high angle and $T_2$ (Daehung vein) developes continuously. 4) When ${\sigma}_1$ changes to sinistral sense, $T_3$ (basic dyke) occurs. 5) When a reverse fault becomes active, the Sangban vein is branched from the Guksabong vein.

• Applied Chemistry for Engineering
• /
• v.21 no.4
• /
• pp.377-384
• /
• 2010

We perform a comparative study to investigate the properties of the new energetic chain extender (AzPD). A series of poly(glycidyl azide)/poly(tetramethylene oxide)-based energetic segmented polyurethane (GAP/PTMG ESPU) with different chain extender, which is 3-azidopropane-1,2-diol (AzPD), 1,4-butane diol (1,4-BD), or 1,5 pentane diol (1,5-PD), was synthesized by solution polymerization in dimethyl formamide (DMF) and their phase behaviors were investigated. The ESPUs were characterized with Fourier transform infrared-attenuated total reflection spectroscopy (ATR FT-IR), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). The results of the ATR FT-IR analysis of the urethane carbonyl group region showed that the 'free' C=O fraction was higher in GAP/PTMG AzESPU (0.5) than GAP/PTMG BDESPU (0.44) and GAP/PTMG PDESPU (0.41) for 7 days samples after preparation and that it was similar in the range of 0.26~0.29 for three 60 days ESPU samples. DMA curves of the GAP/PTMG AzESPU for 7 days samples showed amorphous polymers, but GAP/PTMG BDESPU and GAP/PTMG PDESPU showed viscoelastic behaviors with rubbery plateau and the flow region. However, DMA curves of the GAP/PTMG AzESPU for 60 days samples showed viscoelastic behaviors with rubbery plateau and the flow region like GAP/PTMG PDESPU, but GAP/PTMG BDESPU did not show the flow region. From phase behaviors with ATR FT-IR, DSC and DMA analysis, GAP/PTMG AzESPU showed good phase-mixing between components. However, it represented viscoelastic behavior of TPE similar to GAP/PTMG PDESPM according to phase equilibrium progress with aging time.

• International Journal of Highway Engineering
• /
• v.13 no.3
• /
• pp.21-30
• /
• 2011

As well known, dowel bars are used to transfer traffic load acting on one edge to another edge of concrete slab in concrete pavement system. The dowel bars widely used in South Korea are round shape steel bar and they shows satisfactory performance under bending stress which is developed by repetitive traffic loading and environment loading. However, they are not invulnerable to erosion that may be caused by moisture from masonry joint or bottom of the pavement system. Especially, the erosion could rapidly progress with saline to prevent frost of snow in winter time. The problem under this circumstance is that the erosion not only drops strength of the steel dower bar but also comes with volume expansion of the steel dowel bar which can reduce load transferring efficiency of the steel dowel bar. To avoid this erosion problem in reasonable expenses, dowers bars with various materials are being developed. Fiber reinforced plastic(FRP) dower that is presented in this paper is suggested as an alternative of the steel dowel bar and it shows competitive resistance against erosion and tensile stress. The FRP dowel bar is developed in tube shape and is filled with high strength no shrinkage. Several slab thickness designs with the FRP dowel bars are performed by evaluating bearing stress between the dowel bar and concrete slab. To calculated the bearing stresses, theoretical formulation and finite element method(FEM) are utilized with material properties measured from laboratory tests. The results show that both FRP tube dowel bars with diameters of 32mm and 40mm satisfy bearing stress requirement for dowel bars. Also, with consideration that lean concrete is typical material to support concrete slab in South Korea, which means low load transfer efficiency and, therefore, low bearing stress, the FRP tube dowel bar can be used as a replacement of round shape steel bar.

• Journal of Korea Water Resources Association
• /
• v.44 no.10
• /
• pp.797-807
• /
• 2011

Phenomenon of vegetation recruitment on the sand bar is drastically rising in the streams and rivers in Korea. In the 1960s prior to industrialization and urbanization, most of the streams were consisted of sands and gravels, what we call, 'White River'. Owing to dam construction, stream maintenance, etc. carried out since the '70s, the characteristic of flow duration and sediment transport have been disturbed resulting in the abundance of vegetation in the waterfront, that is, 'Green River' is under progress. This study purposed to identify the correlation among water level, water temperature, rainfall, soil moisture and soil texture out of the factors which give an effect on the vegetation recruitment on the sand bar of unregulated stream. To this purpose, this study selected the downstream of Naeseong Stream, one of sand rivers in Korea, as the river section for test and conducted the monitoring and analysis for 289 days. In addition, this study analyzed the aerial photos taken from 1970 to 2009 in order to identify the aged change in vegetation from the past to the present. The range of the tested river section was 361 m in transverse length and about 2 km in longitudinal length. According to the survey analysis, the tested river section in Naeseong Stream was a gaining river showing the higher underground-water level by 20~30 m compared to Stream water level. The difference in the underground water temperature was less than $5^{\circ}C$ by day and season and the Stream temperature did not fall to $10^{\circ}C$ and less from May when the vegetation germination begins in earnest. The impact factor on soil moisture was the underground water level in the lower layer and the rainfall in the upper layer and it was found that all the upper and lower layer were influenced by soil particle size. The soil from surface to 1 m-underground out of 6 soil moisture-measured points was sand with the $D_{50}$ size of 0.07~1.37 mm and it's assumed that the capillary height possible in the particle size would reach around 14~43 cm. On the other hand, according to the result of space analysis on the tested river section of unregulated stream for 40 years, it was found that the artificial disturbance and drought promoted the vegetation recruitment and the flooding resulted in the frequency extinction of vegetation communities. Even though the small and large scales of recruitment and extinction in vegetation have been repeated since 1970, the present vegetation area increased clearly compared to the past. It's found that the vegetation area is gradually increasing over time.

• Journal of Korean Academy of Nursing
• /
• v.20 no.2
• /
• pp.227-248
• /
• 1990

The study was conceived in relation to a concern over the growing gap between the needs of chronic patients and the availability of care from the current health care system in Korea. Patients with agonizing chronic pain, discomfort, despair and disability are left with helplessly unprepared families with little help from the acute care oriented health care system after discharge from hospital. There is a great need for the development of an alternative means of quality care that is economically feasible and culturally adaptible to our society. Thus, the study was designed to demonstrate the effectiveness of home heath care as an alternative to bridge the existing gap between the patients' needs and the current practice of health care. The study specifically purports to test the effects of home care on health expenditure, readmission, job retention, compliance to health care regime, general conditions, complications, and self-care knowledge and practices. The study was guided by the operations research method advocated by the Primary Health Care Operations Research Institute(PRICOR) which constitutes 3 stages of research : namely, problem analysis solution development, and solution validation. The first step in the operations research was field preparation to develop the necessary consensus and cooperation. This was done through the formation of a consulting body at the hospital and a steering committee among the researchers. For the stage of problem analysis, the Annual Report of Seoul National University Hospital and the patients records for last 5 years were reviewed and selective patient interviews were conducted to find out the magnitude of chronic health problems and areas of unmect health care needs to finally decide on the kinds of health problems to study. On the basis of problem analysis, the solution development stage was devoted to home care program development asa solution alternative. Assessment tools, teaching guidelines and care protocols were developed and tested for their validity. The final stage was the stage of experimentation and evaluation. Patients with liver diseases, hemiplegic and diabetic conditions were selected as study samples. Discharge evaluation, follow up home care, measurement and evaluation were carried out according to the protocols of care and measurement plan for each patient for the period of 6 months after discharge. The study was carried out for the period from Jan. 1987 to Dec. 1989. The following are the results of the study presented according to the hypotheses set forth for the study ; 1. Total expenditures for the period of study were not reduced for the experimental group, however, since the cost per hospital visit is about 4 times as great as the cost per home visit, the effect of cost saving by home care will become a reality as home care replaces part of the hospital visits. 2. The effect on the rate of readmission and job retention was found to be statistically nonsignificant though the number of readmission was less among the experimental group receiving home care. 3. The effect on compliance to the health care regime was found to be statistically significant at the 5% level for hepatopathic and diabetic patients. 4. Education on diet, rest and excise, and medication through home care had an effect on improved liver function test scores, prevention of complications and self - care knowledge in hepatopathic patients at a statistically significant level. 5. In hemiplegic patient, home care had an effect on increased grasping power at a significant level. However. there was no significant difference between the experimental and control groups in the level of compliane, prevention of complications or in self-care practices. 6. In diabetic patients, there was no difference between the experimental and control groups in scores of laboratory tests, appearance of complications, and self-care knowledge or self -care practices. The above findings indicate that a home care program instituted for such short term as 6 months period could not totally demonstrate its effectiveness at a statistically significant level by quantitative analysis however, what was shown in part in this analysis, and in the continuous consultation sought by those who had been in the experimental group, is that home health care has a great potential in retarding or preventing pathological progress, facilitating rehabilitative and productive life, and improving quality of life by adding comfort, confidence and strength to patients and their families. For the further studies of this kind with chronic patients it is recommended that a sample of newly diagnosed patients be followed up for a longer period of time with more frequent observations to demonstrate a more dear- cut picture of the effectiveness of home care.

• The korean journal of orthodontics
• /
• v.31 no.2 s.85
• /
• pp.173-185
• /
• 2001

The orthodontic osseointegrated titanium implant, a kind of intraoral skeletal anchorage can be an alternative to tooth-borne anchorage, in case that the conventional tooth-borne anchorage is not available or the anchorage is critical. This study was conducted to elucidate the effect of early loading on the osseointegration of the orthodontic titanium implant and the healing process of the impaired bone at the site of implant after removing it. In two adult beagle dogs24 osseointegrated titanium implants were inserted into the alveolar bone, with 12 implants placed in each dog. In dog1, 6 out of 12 implants were loaded with 200-300gm of force immediately after placing, and the remaining 6 implants were not loaded for 4weeks. In dog2, all 12 implants had healing period of 4weeks, and then were loaded with 200-300gm of force for another 4weeks. Following an observation period of 4 and 8 weeks, the animals were sacrificed. Then the implants and the surrounding bone of dog1 and dog2 were removed, respectively. Undecalcified sections along the long axis of implant were made and the degree of osseointegration was examined under the light microscope. The results were as follows. 1. In the histologic features of tissues around implants anchored in dog1, there was no difference between immediately loaded implants and unloaded implants. Immature woven bone was ingrowing into the thread spaces from the original compacta and in direct contact with the implant surface in part. 2. The premature loading just after 4weeks healing period did not halt the progress of the osseointegration between bone and implant surface. The woven bone around the implants was maturing into the lamellar bone which resembled the structure of the original compacta at the end of 8weeks observation period. 3. Most implants with the inflammed surrounding mucosa were lost or mobile. The mobile implants were encapsulated by fibrous connective tissue which separated the implant surface from the bone. 4. The impaired bone at the site of the implant failed to anchor was showing recovery without inflammatory reaction 2weeks after removing, with the immaure woven bone lined by active osteoblasts and osteoid. Based on the results of this study, the integration of this orthodontic implant seemed to be impaired by the inflammation of the tissue surrounding the Implant rather than by early loading on implant, and increased with time lapsed after placing the implant. The use of implant described in this report can be recommended as an orthodontic anchorage unit immediately after insertion under the careful control of orthodontic force applied and plaque.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.3 no.1 s.4
• /
• pp.85-96
• /
• 2004

The study begin with a basic concept, if the occupancy length of vehicle detector is directly proportional to the delay of vehicle. That is, it analogize vehicle's delay of a occupancy time. The results of a study was far superior in the estimation of a queue length. It is a very good points the operator is not necessary to optimize s1, s2, Thdoc. Thdoc(critical congestion degree) replaced 0.7 with 0.2 - 0.3. But, if vehicles have been experience in delay was not occupy vehicle detector, the study is in existence some problems. In conclusion, it is necessary that stretch queue detector or install paired queue detector. Also I want to be made steady progress a following study relation to this study, because it is required traffic signal control on congestion.

• Journal of Intelligence and Information Systems
• /
• v.23 no.2
• /
• pp.139-160
• /
• 2017

Technology commercialization creates effective economic value by linking the company's R & D processes and outputs to the market. This technology commercialization is important in that a company can retain and maintain a sustained competitive advantage. In order for a specific technology to be commercialized, it goes through the stage of technical planning, technology research and development, and commercialization. This process involves a lot of time and money. Therefore, the duration and cost of technology commercialization are important decision information for determining the market entry strategy. In addition, it is more important information for a technology investor to rationally evaluate the technology value. In this way, it is very important to scientifically estimate the duration and cost of the technology commercialization. However, research on technology commercialization is insufficient and related methodology are lacking. In this study, we propose an evaluation model that can estimate the duration and cost of R & D technology commercialization for small and medium-sized enterprises. To accomplish this, this study collected the public data of the National Science & Technology Information Service (NTIS) and the survey data provided by the Small and Medium Business Administration. Also this study will develop the estimation model of commercialization duration and cost of R&D performance on using these data based on the market approach, one of the technology valuation methods. Specifically, this study defined the process of commercialization as consisting of development planning, development progress, and commercialization. We collected the data from the NTIS database and the survey of SMEs technical statistics of the Small and Medium Business Administration. We derived the key variables such as stage-wise R&D costs and duration, the factors of the technology itself, the factors of the technology development, and the environmental factors. At first, given data, we estimates the costs and duration in each technology readiness level (basic research, applied research, development research, prototype production, commercialization), for each industry classification. Then, we developed and verified the research model of each industry classification. The results of this study can be summarized as follows. Firstly, it is reflected in the technology valuation model and can be used to estimate the objective economic value of technology. The duration and the cost from the technology development stage to the commercialization stage is a critical factor that has a great influence on the amount of money to discount the future sales from the technology. The results of this study can contribute to more reliable technology valuation because it estimates the commercialization duration and cost scientifically based on past data. Secondly, we have verified models of various fields such as statistical model and data mining model. The statistical model helps us to find the important factors to estimate the duration and cost of technology Commercialization, and the data mining model gives us the rules or algorithms to be applied to an advanced technology valuation system. Finally, this study reaffirms the importance of commercialization costs and durations, which has not been actively studied in previous studies. The results confirm the significant factors to affect the commercialization costs and duration, furthermore the factors are different depending on industry classification. Practically, the results of this study can be reflected in the technology valuation system, which can be provided by national research institutes and R & D staff to provide sophisticated technology valuation. The relevant logic or algorithm of the research result can be implemented independently so that it can be directly reflected in the system, so researchers can use it practically immediately. In conclusion, the results of this study can be a great contribution not only to the theoretical contributions but also to the practical ones.

• Journal of the Korean earth science society
• /
• v.25 no.7
• /
• pp.615-628
• /
• 2004

In order to elucidate seasonal sedimentary characteristics and depositional environment after construction of seawall on macrotidal flat, a seasonal observations of surface sediments (total 450) and sedimentation rates on 4 transects have been investigated for 2 years. The eastern area of Iwon tidal flat, has been changed from semi-closed coast to open coast by construction of seawall, shows general seasonal changes similar to characteristics of open coast type, which represented both fining and bad sorted distribution due to deposition of fine sediments under low energy condition in the summer, and relatively coarser and better sorted distribution because of erosion of fine sediments in the winter. In considering angles of transects, distribution patterns of surface sediments, the northern and southern parts of eastern tidal flat are dominantly influenced by wave and tidal effects, respectively. As time goes by, the eastern tidal flat shows coarsening-trend of surface sediments caused by direct effect of tidal current, were and typhoon. Meanwhile the western area of seawall, which has been re-formed by construction seawall, is sheltered from northwesterly seasonal wind. The seasonal change pattern of western area of seawall is slightly different from that of eastern tidal flat. Mean grain size and sorting of surface sediments during spring is finer and worse than those during summer. This seasonal change pattern maybe influenced by topographic effects caused from the construction of seawall. In consideration of all result, the transport of fine sediments in the study area, which is supplied to limited sediments, shows clockwise circulation pattern that fine sediments are transported from the eastern tidal flat to the western area of seawall because of blocking of seawall in the winter and are transported reversed direction the summer. As a result, many changes have been observed in the study area after construction of seawall; however, this change is still in progress and is expected to need continuous monitoring.

• The Korean Journal of Pharmacology
• /
• v.9 no.1
• /
• pp.1-21
• /
• 1973

During the last decade extensive studios on catecholamines have evolved new knowledge in the physiology and biochemistry of adrenergic mechanism. Cardiac muscle, receiving adrenergic fibres from the stellate, cervical and thoracic ganglia, has been repeatedly shown to have a specific capacity to uptake and to store catecholamines. The catecholamine stores in cardiac muscle have also been shown to be important sites for the action of numerous drugs. Under normal condition, a certain level of catecholamines is maintained in the stores and serves as the basis for studying the changes in the catecholamine content of the heart. Because myocardial catecholamines play such important role in the patho-physiology of the heart, it would be interesting to compare the normal level of myocardial catecholamines among various species of animals. An occasional study has dealt with myocardial catecholamines of several species add ages of animals but these have been insufficiently comprehensive to afford a basis for an understanding of the importance of these amines as related to species and ages. The present investigation was undertaken to determine whether or not there is any significance of myocardial catecholamines in the course of the evolution and development of animals. Seasonal changes, sex difference and regional and subcellular distribution of myocardial catecholamines were also examined. The concentration of cardiac catecholamines was determined by the spectrophotofluorometric procedure described by Shore and Olin. The results obtained were summarized as follows: 1. As animals phylogenetically progressed larger amounts of catecholamines were resent in their hearts. A negligibly small amount of catecholamine was present in the hearts of the clam, a non-vertebrate. Among the vertebrates, cold-blooded animals (snake, turtle, frog, eel and fish) had less myocardial catecholamines than warm-blooded animals, of which aves (fowl and duck) had less than mammalia (cat, dog, rabbit, rat, cow and pig). The ratio of norepinephrine to epinephrine also was greater as the animals progress phylogenetically. 2. Examination of the regional distribution of cardiac catecholamines in warm-blooded animals showed that the content of the auricle was generally higher than that of the septum and considerably than that of the ventricle, but the differences of contents among these regions were not so marked. 3. In the embryonic chick, cardiac catecholamines were firstly detected on the 4th day of incubation, the time before the cardiac innervation of sympathetic nerves. The concentrations of these catecholamines increased but not markedly on the 6th day of incubation, soon after the innervation of sympathetic nerves to the heart. The level of the cardiac catecholamines fluctuated throughout the remainder of embryonic development. 4. In newborn rat hearts, a considerable amount of catecholamines was present. With the development of the rats, the concentrations of myocardial catecholamines increased. The ratio of epinephrine and norepinephrine fluctuated within the range of 40 to 60 pervent. However, as development progressed, the percentage of norepinephrine continued to rise, attaining the adult value of $80{\sim}90%$ after $45{\sim}60$ days. In contrast, the total amount of epinephrine remained fairly constant throughout the animal's development. 5. No significant sexual differences were observed in the concentration of myocardial catecholamines in the developing rat. 6. The catecholamines in the rabbit hearts increased during the summer season (from May to August) and maintained a fairly constant level in the other seasons of the year. 7. The subcellular distribution of cardiac catecholamines was examined by differential centrifugation of homogenates of cardiac muscles in rabbits, cats and rats. The catecholamines were found to be present approximately 20% in particles of mitochondrial fraction, 45% in particles of microsomal fraction and 35% in soluble supernatant fraction. The particle containing catecholamines in cardiac muscle appears to be two different sizes.