• Journal of Korean Society of Rural Planning
• /
• v.4 no.1
• /
• pp.32-39
• /
• 1998

In Korea, rural village improvement has mainly been led by goverment investment. This approach, however, has its own limit since there are so many village to be improved while the budgetary sources are restricted, As an alternative, inducement of private investments to these area is considered in order to promote rural village improvement. The possibility of inducing private investments to the rural village improvement depends on the location of the village. The possibility may be highest in the sub-urban area since expected benefits from land development is usually high. One desirable approach to induce private investment to these area is the cooperative development system. Residents, private investors and governments plays its own role, independently and cooperatively, But benifits from the investment to improve rural village in general plain area are so low that it is difficult to induce the private investments to these area. In that case, indirect development system will be a proper strategy which maintaining government-led development method as usual, expanding the participation of private developers such as the construction companies. In general, rate of returns from investment to the rural sectors is lower than that to the other sectors, therefore financial support such as the long- term, low loan rate and a partial value-added tax exemption should be given to the investors to the rural village improvement projects.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.2
• /
• pp.404-420
• /
• 2021

In this paper, an automatic system of locating the indoor area with weak or no mobile signal was proposed and demonstrated experimentally by using the Internet of Things (IoT) technology. Nowadays, the technicians of mobile services providers need to go along with numerous heavy equipment to measure and record the mobile signal strength at outside environment. Recently, there are systems proposed to do such measurement at outdoor area by using the IoT technology automatically. However, these works could not be applied in the indoor area since there are difficulties to do the indoor mapping and positioning. In this work, the Bluetooth Low Energy (BLE) was used to tackle these two difficulties. After a proper placement of BLE in the testing site, while the technician walk around with a handheld analyzer, the data can be obtained accordingly for further analysis in the proposed system which includes the construction of floor plan, detection of mobile signal strength and suggestion of indoor base stations. The gift wrapping and centroid algorithms were used during the analysis. The experimental results showed that the proposed system successfully demonstrated the indoor mapping, positioning of weak mobile signal area and suggestion of indoor base stations for the normal rectangular rooms with an area of 100 m² on single floor.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.36 no.1
• /
• pp.29-35
• /
• 2023

Herein we investigated the effect of the conductive agent on the electrochemical performance of the SiOx anode. SiOx anodes have a relatively low volume expansion (~160%) compared to Pure-silicon, but have a problem in that they have a poor electrical conductivity characteristic. In this study, physical and electrochemical measurements were performed using two 0-dimensional amorphous carbon conductive agents with different crystallinity and surface area. The crystal structure of the conductive agents and the local graphitization degree were analyzed through XRD and Raman, and the surface area of the particles was observed through BET. In addition, the electrical performance according to the graphitization degree of the conductive agents was confirmed through a 4-point probe. As a result of the electrochemical cycle and rate performance, it was confirmed that the performance of SiOx using a conductive agent having a low graphitization degree and a high surface area was improved. The results in this study suggest that the graphitization degree and surface area of the amorphous carbon conductive agent may play an important role in the SiOx electrode.

• The Korean Journal of Ecology
• /
• v.9 no.1
• /
• pp.25-31
• /
• 1986

A study was made on the change of vegetation in Yungil area after the erosion control works. The area was divided into three major areas, the devastated land area, the afforested area and the subclimax area. Two groups of plant, i.e., the common species in all area and the different species confined in the subclimax area, were identified by the interspecific correlation analysis based on the positive correlation value at 5% significance level. High similarity among the sites in the afforested region was indicated by the DIF (difference measure) value, lower than 0.33. However, the devastated area and the subclimax area were distinguished completely. The change in species diversity has been extremely low since the erosion control works. Robinia pseudo-acacia was the dominant species in the afforested region and showed an adequate growth status.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.40 no.2
• /
• pp.15-23
• /
• 2012

This study was accomplished by analyzing the change of land cover pattern in high-rise buildings in Korea. For this study, we selected 15 locations of high-rise buildings. The ratio of average building coverage and paved area was 79.7%, and both green and water area were low, relatively. The biotope area factor of the site showed low percentage by 15.90% due to the underground space development. As a result of correlation analysis between the time of construction and land-cover type, building coverage has been decreased according to the stream of time. However, biotope area factor has been increased And, the paved area has m correlation. It was identified that reducing paved area is effective to enhance the ecological functions of a high-rise building outdoor.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.23 no.2
• /
• pp.229-250
• /
• 1993

This study was performed to investigate the morphological and structural changes of bone tissues and the effects of irradiation on the mandibular bodies of rats which were fed low calcium diets. In order to carry out this experiment, 160 seven-week old Sprague-Dawley strain rats weighing about 150 gm were selected and equally divided into one normal diet group of 80 rats and one low calcium diet group with the remainder. These groups were then subdivided into two groups, 40 were assigned rats for each subdivided group, exposed to radiation. The Group 1 was composed of forty non-irradiated rats with normal diet, Group 2 of forty irradiated rats with normal diet, Group 3 forty non-irradiated rats with low calcium diet, and Group 4 forty irradiated rats with low calcium diet. The two irradiation groups received a single dose of 20 Gy on the jaw area only and irradiated with a cobalt-50 teletherapy unit. The rats with normal and low calcium diet groups were serially terminated by ten on the 3rd, the 7th, the 14th, and the 21st day after irradiation. After termination, both sides of the dead rats mandible were removed and fixed with 10% neutral formalin. The bone density of mandibular body was measured by use of bone mineral densitometer(Model DPX -alpha, Lunar Corp., U.SA). Triga Mark ill nuclear reactor in Korea Atomic Research Institute was used for neutron activation and then calcium contents of mandibular body were measured by using a 4096 multichannel analyzer (EG and G ORTEC 919 MCA, U.SA). Also the mandibular body was radiographed with a soft X-ray apparatus(Hitex Co., Ltd., Japan). Thereafter, the obtained microradiograms were observed by a light microscope and were used for the morphometric analysis using a image analyzer(Leco 2001 System, Leco Co., Canada). The morphometric analysis was performed for parameters such as the total area, the bone area, the inner and outer perimeters of the bone. The obtained results were as follows: 1. In the morphometric analysis, total area and outer perimeter of the mandibular bodies of Group 3 were a little smaller than that of Group 1. The mean bone width and bone area were much smaller than that of Group 1 and the inner perimeter of Group 3 was much longer than that of Group 1. The total area and outer perimeter of Group 2 and Group 4 showed little difference. The mean bone width and bone area of Group 4 were smaller than that of Group 2 and the inner perimeter of Group 4 was longer than that of Group 2. 2. The remarkable decreases of the number and thickness of trabeculae and also the resorption of endosteal surface of cortical bone could be seen in the microradiogram of Group 3, Group 4 since the 3rd day of experiment. On the 21st day of experiment, the above findings could be more clearly seen in Group 4 than in Group 3. 3. The bone mineral density of Group 3 was lesser than that of Group 1 and the bone mineral density of Group 4 was lesser than that of Group 2 on the 7th, 14th, 21st days. The irradiation caused the bone mineral density to be decreased regardless of diet. In the case of Groups with low calcium diet, the bone mineral density was much decreased on the 21st day than on the 3rd day of experiment. 4. The calcium content in mandible of Group 3 was smaller than that of Group 1 throughout the experiment. roup 4 showed the least amount of calcium content. The irradiation caused the calcium content to be decreased regardless of diet. In the case of Groups with low calcium diet, the calcium content was much decreased on the 21st day than on the 3rd day of experiment. In conclusion, the present study demonstrated that morphological changs and decrease of bone mass due to resorption of bone by low calcium diet, and that the resorption of bone could be found in the spongeous bone and endosteal surface of cortical bone. So the problem of resorption of bone must be considered when the old and the postmenopausal women are taken radiotherapy because the irradiation seems to be accelerated the resorption of osteoporotic bone.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.3 no.4
• /
• pp.203-213
• /
• 1998

To investigate impacts of waste disposal on the marine environment for 9 years since dumping activity commenced in the Yellow Sea, chemical analysis of seawater has been done in and around the ocean dumping site. Results show that biogeochemical changes have occurred locally in the dumping area compared with the reference area, resulting in low dissolved oxygen saturation, low pH, and high accumulation of nutrients in the bottom layer. According to cluster analysis, chemical environment of the study area can be largely divided into surface layer and bottom layer, and again the bottom layer can be divided into that of dumping area where nutrients are accumulated and that of reference area. Low pH, low dissolved oxygen, high COD and accumulation of nutrients mainly characterize the dumping area. Average concentration of total inorganic nitrogen in the bottom layer below the thermocline has increased from $3.7{\mu}M$ to $9.5{\mu}M$, 250% accumulation in the dumping area since 1988. Therefore, the present results clearly show that the dumping site of Yellow Sea has received excessive sewage input beyond the environmental assimilatory capacity during the last decade. It may result in serious aggravation of seawater quality and basic ecosystem, and devastation of overall fishing grounds of Yellow Sea in the near future.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2016.02a
• /
• pp.416-416
• /
• 2016

Organic-inorganic metal halide perovskite solar cells have received attention because it has a number of advantages with excellent light harvesting, high carrier mobility, and facile solution processability and also recorded recently power conversion efficiency (PCEs) of over 20%. The major issue on perovskite solar cells have been reached the limit of small area laboratory scale devices produced using fabrication techniques such as spin coating and physical vapor deposition which are incompatible with low-cost and large area fabrication of perovskite solar cells using printing and coating techniques. To solution these problems, we have investigated the feasibility of achieving fully printable perovskite solar cells by the blade-coating technique. The blade-coating fabrication has been widely used to fabricate organic solar cells (OSCs) and is proven to be a simple, environment-friendly, and low-cost method for the solution-processed photovoltaic. Moreover, the film morphology control in the blade-coating method is much easier than the spray coating and roll-to-roll printing; high-quality photoactive layers with controllable thickness can be performed by using a precisely polished blade with low surface roughness and coating gap control between blade and coating substrate[1]. In order to fabricate perovskite devices with good efficiency, one of the main factors in printed electronic processing is the fabrication of thin films with controlled morphology, high surface coverage and minimum pinholes for high performance, printed thin film perovskite solar cells. Charge dissociation efficiency, charge transport and diffusion length of charge species are dependent on the crystallinity of the film [2]. We fabricated the printed perovskite solar cells with large area and flexible by the bar-coating. The morphology of printed film could be closely related with the condition of the bar-coating technique such as coating speed, concentration and amount of solution, drying condition, and suitable film thickness was also studied by using the optical analysis with SEM. Electrical performance of printed devices is gives hysteresis and efficiency distribution.

• Korean Journal of Plant Resources
• /
• v.16 no.1
• /
• pp.25-33
• /
• 2003

Different ages of the ginsengs were collected from the three soil areas, such as granite, phyllite and shale of Keumsan, with their field soils. Of the soils, phyllite and shale areas are high in the Ni, Cr, Co, Sc, V, As, Cu and Zn contents while the granite areas are low in the W, Pb, Th, U, Sn and Be contents. In the correlation coefficient of the soils, positive and negative relationships of the elements are mainly high in the shale and low in the granite area. Comparing between 2- and 3- year ginsengs, 2-year ginsengs are mainly high in most elements, especially for the granite and phyllite areas. In the regional comparisons among the same ages, the granite areas are mainly low and high in the shale area for the most of the elements. Comparisons among the parts of ginsengs suggest high contents in the most of the elements at the upper parts. In the comparisons between the top soils and ginseng compositions, top soils are mainly high and show similar increase/decrease trends between them. Following the transitional element contents, the granite area is best for the ginseng cultivation while , among the three areas, the shale area is worst.

• Proceeding of Spring/Autumn Annual Conference of KHA
• /
• 2009.04a
• /
• pp.84-87
• /
• 2009

This study aims to analyze characteristics of residents' housing life-style targeting Gatdui area and Daean area where the housing environment improvement project is carried out in the form of rehabilitation housing renewal program of old residence of the downtown area in Kyungju. This is in order to examine realistic problems of the method of residential improvement project, where residents' voluntary participation and preferences are low for low-income residents by seeking the methods of rehabilitation which correspond with the fundamental objective of the housing environment improvement project for low-income residents in urban areas. Based on the survey, we analyzed residents' satisfaction level with the current way of living and preferred ways of living and the planar pattern of houses in surveyed areas, and examined the housing environment improvement methods for residents living in the urban slam areas and perception of subjects. Survey analysis used statistics program SPSS14.0. As a result, of it, it was found that residents in surveyed areas were relatively satisfied with the current way of living but in the preferred housing life-style, they were demanding some change. This paper is significant in that it aims at change in paradigm of improvement of residential areas through renewal of urban deteriorated residence that characteristics of changing living space are compromised depending on living habitude left, and changing life style, and it proposes the directions of the housing environment improvement plan in the future.