• Spatial Information Research
• /
• v.14 no.1 s.36
• /
• pp.163-176
• /
• 2006

The concept of 'spatial association' explains spatial distribution pattern of geographical phenomenon based on similarity with neighborhoods, as in the Tobler's Law of Geography: 'Everything is related to everything else, but near things are more related than distant things.' In this study, we develop a time-series exploratory analysis tool for discovering temporal patterns of spatial association by combining spatial statistics and geo-visualization, and thus present a possibility to support spatial decision-making process. As for the spatial proximity weight matrix indispensable to measuring global and local spatial association, we employ a variety of flexible weighting schemes using geometric characteristics of areal unit. In addition, we renovate the existing visualization methods for more effective understanding of the procedures and results of time-series analysis on spatial association: for instance, temporal parallel coordinate plot with box plot, animated map for spatial association, and 3D Moran scatterplot. The feasibility of our system is verified by time-series analysis experiments on the spatial association of land price fluctuation rate for all administrative units in Korea, $1995{\sim}2004$.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38B no.5
• /
• pp.394-400
• /
• 2013

WoT (Web of Things) was proposed to realize intelligent thing to thing communications using WEB standard technology. It is difficult to adapt security protocols suited for existing Internet communications into WoT directly because WoT includes LLN(Low-power, Lossy Network) and resource constrained sensor devices. Recently, IETF standard group propose to use DTLS protocol for supporting security services in WoT environments. However, DTLS protocol is not an efficient solution for supporting end to end security in WoT since it introduces complex handshaking procedures and high communication overheads. We, therefore, divide WoT environment into two areas- one is DTLS enabled area and the other is an area using lightweight security scheme in order to improve them. Then we propose a mutual authentication scheme and a session key distribution scheme for the second area. The proposed system utilizes a smart device as a mobile gateway and WoT proxy. In the proposed authentication scheme, we modify the ISO 9798 standard to reduce both communication overhead and computing time of cryptographic primitives. In addition, our scheme is able to defend against replay attacks, spoofing attacks, select plaintext/ciphertext attacks, and DoS attacks, etc.

• Journal of Korean Society for Geospatial Information Science
• /
• v.23 no.3
• /
• pp.77-84
• /
• 2015

The key objective of this research is to review the effectiveness of spatial regression to identify the influencing factors of spatial distribution patterns of floating population. To this end, global and local spatial autocorrelation test were performed using seoul floating population survey(2014) data. The result of Moran's I and Getis-Ord $Gi^*$ as used in the analysis derived spatial heterogeneity and spatial similarities of floating population patterns in a statistically significant range. Accordingly, Geographically Weighted Regression was applied to identify the relationship between land use attributes and population floating. Urbanization area, green tract of land of micro land cover data were aggregated in to $400m{\times}400m$ grid boundary of Seoul. Additionally public transportation variables such as intersection density transit accessibility, road density and pedestrian passage density were adopted as transit environmental factors. As a result, the GWR model derived more improved results than Ordinary Least Square(OLS) regression model. Furthermore, the spatial variation of applied local effect of independent variables for the floating population distributions.

• The Journal of the Korea Contents Association
• /
• v.14 no.9
• /
• pp.529-537
• /
• 2014

To establish a foundation to objectively interpret Chosun history, we construct people network of the Chosun dynasty. The network shows scale free network properties as if most social networks do. The people network is composed of 1,379 nodes and 3,874 links and its diameter is 14. To analysis of the network dynamics, whole network that is composed of 27 king networks were constructed by adding the first king, Taejo network to the second king, Jeongjong network and then continuously adding the next king networks. Interestingly, betweenness and closeness centralities were gradually decreased but stress centrality was drastically increased. These results indicate that information flow is gradually slowing and hub node position is more centrally oriented as growing the network. To elucidate key persons from the network, k-core and MCODE algorithms that can extract core or module structures from whole network were employed. It is a possible to obtain new insight and hidden information by analyzing network dynamics. Due to lack of the dynamic interacting data, there is a limit for network dynamic research. In spite of using concise data, this research provides us a possibility that annals of the Chosun dynasty are very useful historical data for analyzing network dynamics.

• Journal of the Korean Applied Science and Technology
• /
• v.20 no.2
• /
• pp.101-109
• /
• 2003

Provitamin $B_5$ liquid crystal ($PVB_5$-LC) was the new emulsion system to enhance moisturizing activity on the skin. In this study, it should be mentioned that PVB5-LC could be prepared with the main compound of hydrogenated lecithin (HL) in oil-in water (O/W) emulsion. The key ingredient of humectants was contained 2% of provitamin $B_5$ ($PVB_5$) into the $PVB_5$-LC. The best suitable compositions of $PVB_5$-LC were made from 4.0 wt% of HL, 4.0 wt% of cetostearyl alcohol (CSA) as emulsifier and gelling agent, 3.0 wt% of 1,3-butylene glycol (1,3-BG) and 2.0 wt% of glycerin as moisturizers, 3.0 wt% of cyclomethicone (CMC), 3.0 wt% of isononanoate (ININ), 3.0 wt% of capric/caprylic triglyceride (CCTG), 3.0 wt% of macadamia nut oil (MNO) as emollients. As the analytical result of $PVB_5$-LC, it could know that the distribution range of particle size was 0.14 to 12.37 m level (mean size 3.24 m). It was certified the multi lamellar phase around the droplet of liquid crystal when observed the droplet particles through a polarization microscope. And it clinically was tested the effectiveness of moisturizing activity (in-vivo) compared with control sample (O/W emulsion). The effectiveness of moisturizing activity of $PVB_5$-LC with Skincon-200EX after 6 hours went up 49.0% (p<0.05, n=20) whereas the effectiveness of moisturizing activity of generally O/W emulsion cream was 25.7% (p<005, n=20). Also, in case of Comeometer CM-825, the moisturizing activity of $PVB_5$-LC after 6 hours rose 36.6% (p<0.05, n=20) whereas the effectiveness of moisturizing activity of generally O/W emulsion cream was 10.8%. Therefore, it was known that the effectiveness moisturizing activity of $PVB_5$-LC with HL was remarkably superior compared with O/W emulsion cream.

• Journal of Korean Society of Forest Science
• /
• v.98 no.5
• /
• pp.548-557
• /
• 2009

For centuries, forests have been a key component of rural livelihood. They are important both socially and economically in Nepal. Firewood and fodder are the basic forest products that are extracted daily or weekly basis in most of the rural areas in Nepal. In this study, a field survey of 100 households was conducted to examine the degree of forest dependency and forest resource availability, households' livelihood strategy and their relationship with forest dependency in Chitwan, Nepal. A household' response indexes were constructed, Gini coefficient, Head Count Poverty Index (HCI) and Poverty Gap Index (PGI) were calculated and one way ANOVA test was also performed for data analysis. Data revealed that 82/81% of all households were constantly used forest for firewood and fodder collection respectively while 42% of households were used forest or forest fringe for grazing. The Forest Product Availability Indexes (FPAI) showed a sharp decline of forest resources from 0.781 to 0.308 for a 20-yr time horizon while timber wood was noticeably lowered than the other products. Yet, about 33% of households were below the poverty threshold line with 0.0945 PGI. Income distribution among the household showed a lower Gini coefficient 0.25 than 0.37 of landholdings size. However, mean income was significantly varies with F-statistics=246.348 at P=0.05 between income groups (rich, medium and poor). The extraction of firewood, fodder and other forest products were significantly different between the income group with F-statistics=16.480, 19.930, 29.956 at P=0.05 respectively. Similarly, landholdings size and education were also significantly different between the income groups with F-statistics=4.333, 5.981 at P=0.05 respectively. These findings suggested that income status of households was the major indicator of forest dependency while poor and medium groups were highly dependent on the forests for firewood, fodder and other products. Forest dependency still remains high and the availability of forest products that can be extracted from the remaining forestlands is decreasing. The high dependency of households on forest coupled with other socioeconomic attributes like education, poverty, small landholders and so on were possibly caused the forest degradation in Chitwan.Therefore, policy must be directed towards the poor livelihood supporting agenda that may enhance the financial conditions of rural households while it could reduce the degree of forest dependency inspired with other income generating activities in due course.

• Advances in Traditional Medicine
• /
• v.4 no.2
• /
• pp.104-111
• /
• 2004

Sasang Constitutional Medicine is a major branch of Korean Traditional Oriental Medicine. The differences of disease susceptibility to be shown in Sasang constitution may be due to genetic factors. Therefore, we examined interrelationship among cerebral infarction (CI), apolipoprotein E (apoE) gene polymorphism, and Sasang constitutional classification. ApoE is a key protein modulating the highly atherogenic apoB containing lipoproteins and is a candidate gene for the development of coronary artery disease (CAD). The ${\varepsilon}2\;and/or\;{\varepsilon}4$ alleles were the first to be implicated in premature CAD, which resulted in this polymorphism being extensively studied. We investigated the association between apoE genotype and CI by case-control study in a Korean population. We also classified CI patients and control group into groups according to Sasang Constitutional Medicine. 196 CI patients and 379 controls without CI were examined. ApoE genotype was determined by 8% polyacrylamide gel separation after DNA amplification. A significant difference in the apoE genotype distribution was observed in the CI patients compared with that in controls ($X^{2}$=14.920, df=4, P=0.005). Also, the frequency of Taeumin constitution in patients with CI was significantly higher than that in controls (58.0% vs. 36.9%; P<0.001). However, the Taeumin constitution did not enhance the relative risk for CI in the subjects with apoE ${\varepsilon}2\;and/or\;{\varepsilon}4$ alleles. No differences in the apoE genotypes frequencies were observed in the Taeumin compared with that in the other constitutions. In addition, we investigated whether the DD genotype of angiotensin converting enzyme (ACE) gene, a candidate gene for CI, was associated with CI, Taeumin constitution, and apoE polymorphism. As a result, the frequency of Taeumin constitution was significantly higher in CI patients with both apoE ${\varepsilon}3/{\varepsilon}4$ and ACE ID/DD genotypes than in the remaining Sasang constitutions (14.5% vs. 8.3% and 0%) ($X^{2}$=13.521, df=6, P=0.035). In summary, we concluded that the apoE polymorphism is a major risk factor for CI in Koreans and the ACE ID/DD genotype enhanced the relative risk for CI in the subjects with apoE ${\varepsilon}3/{\varepsilon}4$ genotype and Taeumin constitution.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.16 no.2
• /
• pp.189-199
• /
• 2016

Pending issues present in the Nation Technical Qualifications System (NTQS) have been discussed to deal with the causes and improvements of the issues. The key present situations of the NTQS were investigated to analyze the problems of the NTQS. The acquisition distribution of the items of additional points in employment and the items applied to the laws and regulations of duty employment was revealed to be related with preferential items. The AHP analysis has been conducted based on issues for improvement of the NTQS raised till now. The urgency priority of the elements to be improved was ranked according to the AHP analysis result. The agendas for the improvement of the NTQS was suggested by consideration of the priority of the elements. First, a solution to raise discrimination of the NTQS was suggested by taking the view points of the experts into account. Second, an opinion was proposed that the preferential policies in employment should be directed toward expansion of qualification for duty employment. Third, two ideas were proposed to rectify problems embedded in the technician career handbook system. And four remedies have been made suggested, including the merger of similar events. The results of this research are expected to serve as a useful material for the future design of the NTQS.

• Proceedings of the Korean Society of Environment and Ecology Conference
• /
• 2003.10a
• /
• pp.105-126
• /
• 2003

In Korea most of annual rainfall is concentrated in several episodic heavy rains during the season of summer monsoon and typhoon. Because of uneven rainfall distribution many dams have been constructed in order to secure water supply in dry seasons. The Han River system has the most dams among Korean rivers, and the river is a series of dams now. Reservoirs need different strategy of water quality control from river water. Autochthonous organic matter and phosphorus should be the major target to be controlled in lakes. In this Paper some problems are discussed that makes efforts of water quality improvement ineffective in lakes of Korea, even after the substantial investment to wastewater treatment facilities.1) Phosphorus is the key factor controlling eutrophication of lakes and the reduction ofphosphors should be the major target of water treatment. However, water quality management strategy in Korea is still stream-oriented, and focused on BOD removal from sewage. Phosphorus removal efficiency remains as low as 10-30%, because biological treatment is adopted for both secondary treatment and advanced treatment. The standard for TP concentration of the sewage treatment plant effluent is 6 mgP/l in most of regions, and 2 mg/l in enforced region near metropolitan water intake point. TP in the effluents of sewage treatment plants are usually 1-2 mg/1, and most of plants meet the effluent regulation without a further phosphorus removal process. The generous TP standard for effluents discourages further efforts to improve phosphorus removal efficiency of sewage treatment. Considering that TP standard for the effluent is below 0.1 mg/l in some countries, it should be amended to below 0.1 mg/l in Korea, especially in the watershed of large lakes.2) Urban runoff and combined sewer overflow are not treated, even though their total loading into lakes can be comparable to municipal sewage discharges on dry days. Chemical coagulation and rapid settling might be the solution to urban runoff in regard of intermittent operation on only rainy days.3) Aggregated precipitation in Korea that is concentrated on several episodic heavyrains per year causes a large amount of nonpoint source pollution loading into lakes. It makes the treatment of nonpoint source discharge by methods of other countries of even rain pattern, such as retention pond or artificial wetland, impractical in Korea.4) The application rate of fertilizers in Korea is ten times as high as the average ofOECD countries. The total manure discharge from animal farming is thought to be over the capacity of soil treatment in Korea. Even though large portion of manure is composted for organic fertilizer, a lot of nutrients and organic matter emanates from organic compost. The reduction of application rate and discharge rate of phosphorus from agricultural fields should be encouraged by incentives and regulations.5) There is a lot of vegetable fields with high slopes in the upstream region of the HanRiver. Soil erosion is severe due to high slopes, and fertilizer is discharged in the form of adsorbed phosphorus on clay surface. The reduction of soil erosion in the upland area should be the major preventive policy for eutrophication. Uplands of high slope must be recovered to forest, and eroded gullies should be reformed into grass-buffered natural streams which are wider and resistant to bank erosion.

• International Commerce and Information Review
• /
• v.17 no.1
• /
• pp.217-240
• /
• 2015

This paper uses the modified gravity model of international trade to examine the impact of ODA on the export of Korea to 28 aid recipients. In this perspective, the study includes recipient's economic size, trade openness, population, donor's scale of aid and distance between them as key determinants of the export of Korea by using panel data over the period of 2005-2012. To do this task, important econometric methods are fulfilled to test the model adequately, such as panel unit root and panel co-integration test. In addition, the study incorporated the panel OLS, panel GLM and panel EGLS methods. The empirical analysis clearly showed that an increase in Korea's ODA promotes its own exports. The coefficients of recipients's per capita GDP, population and trade openness have a positive impact on Korea's export respectively, while distance between them has a negative impact. Regarding regional dummy variables, aid for the region of Africa and America have a negative impact on Korea's export. Overall, the main implication of this study is that even if it emphasized Korea's economic interests as determinants of ODA disbursements, but it also suggests that an improvement of recipient's economic development, income distribution and educational environment can be an important concern in the future.