• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.12 no.4
• /
• pp.47-71
• /
• 2009

The resource plants of northern region in Gapyeong-gun were investigated 7 times from Apr. 2007 to Oct. 2007. In the result of survey, the flora of this area, depend on voucher specimens, consist of 480 taxa totally; 94 families, 286 genera, 412 species, 4 subspecies, 52 varieties and 12 forms. The Resource plants in this area were categorized by their use into edible 177, pasturing 136, medicinal 124, stainable 69, ornamental 133, afforest 24, timber 10, fiber 6, industrial 2 taxa and unknown use plants 72, respectively. There were remarkable plants such as 14 taxa of Korean endemic plants, 85 taxa of specific plants which were designated by the Ministry of Environment, and 12 taxa of rare and endangered plants of Korea Forest Service. Furthermore, 22 taxa of naturalized plants 4.6% were also observed in this area and Urban Index (UI) was 8.2%. The vegetation status of investigated area was comparatively well conserved, but the degree of UI could be increased rapidly by the climbers, development of forest road. Therefore, the systems for conservation need to prepared for the effective management of forest, and the special plans need to control the number of climbers and visitors.

• Korean Journal of Ecology and Environment
• /
• v.51 no.3
• /
• pp.234-244
• /
• 2018

The roadkill that animals die after bumping by vehicles on the roads is acting as a factor to decrease the size of various animal populations. It has also been known to be the biggest artificial causations of Vertebrata deaths not only in urban areas but also protected areas such as national parks. Nevertheless, in the national park areas which are major protected national areas for conservation of national biodiversity and ecological diversity, snake roadkills occur frequently. Up to date, related studies are rare. Therefore, in this study, we described snake roadkill patterns on the roads in six national parks between 2006 and 2015. We identified total 736 snake roadkills compromising 10 different species. Five species, Rhabdophis lateralis, Elaphe dione, Gloydius ussuriensis, Lycodon rufozonatus, Gloydius brevicaudus occupied more than 91.7% of total roadkill cases. Active forager snakes were killed by roadkills more than ambush foragers, and the snake roadkill frequency was the highest in September, a migration period and in August when the young individuals dispersed at between 100 and 799 m altitude areas. Roads where roadkills were frequent lie between forest and hydrosphere or between forest and crop field road sides. Our results could be used to identify the trend of snake roadkills on the roads in national parks, and to establish effective roadkill mitigation measures and policies.

• The Journal of Korean Institute of Information Technology
• /
• v.15 no.12
• /
• pp.181-188
• /
• 2017

As a population of leisure activities grows and diversifies, there is a great demand for portable and environment-friendly power generation systems. A small wind power generation system is emerging as a suitable power generation equipment to meet these needs. The most important thing when developing a small portable wind turbine is to reduce the weight of the generator and increase the efficiency. The existing 300W wind turbine generator weighs about 10kg, which is heavy to carry. Therefore, a new generator weighing less than 4kg to make it easy to carry with high efficiency has been developed. In addition, considering complicated characteristics of wind volume and topography of Korea, a small wind turbine that can be used in urban and rural areas individually was constructed. Through basic designing and optimization, the lightweight and efficient generator was manufactured. It is a 300W wind turbine designed and fabricated with reduced weight as a prototype. The average output voltage of the generator was 24.7V at 900rpm no-load test. On a load test with the average line voltage 36.8V and the average phase current 2.62A, when the mechanical input was 339.84W, an average voltage output of the generator was measured as 289.5W with efficiency of 85.18%. The generator weight was 3.84kg.

• Journal of Convergence for Information Technology
• /
• v.11 no.11
• /
• pp.172-177
• /
• 2021

As part of the digital era, a digital twin that simulates the weak part of a product by performing a stress test that reduces the lifespan of some expensive equipment that cannot be done in reality by accurately moving the real world to virtual reality is being actively used in the manufacturing industry. Due to the development of IoT, the digital twin, which accurately collects data collected from the real world and makes it the same in the virtual space, is mutually beneficial through accurate prediction of urban life problems such as traffic, disaster, housing, quarantine, energy, environment, and aging. Based on its action, it is positioned as a necessary tool for smart city construction. Although digital twin is widely applied to the manufacturing field, this study proposes a smart city model suitable for the 4th industrial revolution era by using it to smart cities and increasing citizens' safety, welfare, and convenience through the proposed model. In addition, when a digital twin is applied to a smart city, it is expected that more accurate prediction and analysis will be possible by real-time synchronization between the real and virtual by maintaining realism and immediacy through real-time interaction.

• Journal of Korean Society of Disaster and Security
• /
• v.15 no.4
• /
• pp.87-98
• /
• 2022

In recent years, frequent localized heavy rainfalls, which have a lot of rainfall in a short period of time, have been increasingly causing flooding damages. To prevent damage caused by localized heavy rainfalls, Hydrological Quantitative Precipitation Forecast (HQPF) was developed using the Local ENsemble prediction System (LENS) provided by the Korea Meteorological Administration (KMA) and Machine Learning and Probability Matching (PM) techniques using Digital forecast data. HQPF is produced as information on the impact of heavy rainfall to prepare for flooding damage caused by localized heavy rainfalls, but there is a tendency to overestimate the low rainfall intensity. In this study, we improved HQPF by expanding the period of machine learning data, analyzing ensemble techniques, and changing the process of Probability Matching (PM) techniques to improve predictive accuracy and over-predictive propensity of HQPF. In order to evaluate the predictive performance of the improved HQPF, we performed the predictive performance verification on heavy rainfall cases caused by the Changma front from August 27, 2021 to September 3, 2021. We found that the improved HQPF showed a significantly improved prediction accuracy for rainfall below 10 mm, as well as the over-prediction tendency, such as predicting the likelihood of occurrence and rainfall area similar to observation.

• Journal of the Korean Geographical Society
• /
• v.47 no.3
• /
• pp.375-389
• /
• 2012

Many policy makers believe that geographically clustered business activities, in order to stimulate regional innovation, are the keys to development. Underlying the assumption between cluster and development, mere co-located forms engaged in innovative process helped from knowledge transmission locally. To address the constraints of creative economy, creative milieu require networking to support innovation activities. This paper examines the development of the mini cluster reconsidered in creative milieu that shifted environment development through network activities. It shows that the powerful node get more powerful, weak node get weaker in institutional network. Moreover, the significant of cluster in creative milieu is that brings out synergy to spill over knowledge through inter-relationship based on face-to-face meeting. Creative milieu benefits from and contributes to the competitiveness of the city, they are also embedded in its network activities.

• Journal of Korea Water Resources Association
• /
• v.45 no.3
• /
• pp.275-290
• /
• 2012

In this study, we have developed an optimal time distribution model through extraction of peaks over threshold (POT) series. The median values for annual maximum rainfall dataset, which are obtained from the magnetic recording (MMR) and the automatic weather system(AWS) data at Seoul meteorological observatory, were used as the POT criteria. We also suggested the improved methodology for the time distribution of extreme rainfall compared to Huff method, which is widely used for time distributions of design rainfall. The Huff method did not consider changing in the shape of time distribution for each rainfall durations and rainfall criteria as total amount of rainfall for each rainfall events. This study have suggested an extracting methodology for rainfall events in each quartile based on interquartile range (IQR) matrix and selection for the mode quartile storm to determine the ranking cosidering weighting factors on minutely observation data. Finally, the optimal time distribution model in each rainfall duration was derived considering both data size and characteristics of distribution using kernel density function in extracted dimensionless unit rainfall hyetograph.

• Journal of Korean Society of Environmental Engineers
• /
• v.28 no.12
• /
• pp.1287-1292
• /
• 2006

Constructed wetlands are well known as highly efficient system to treat wastewater from different sources. Among the constructed wetlands, upflow types of constructed wetlands have become a common selection of wastewater during the last decade. We conducted a pilot scale study at peen house on treating potential of nutrients by upflow vegetated filter(UVF) pilot wetland which was combined with hydrodynamic separator and used the cattail plant(Typha angustifolia), and operated with artificial nutrients influent. This study evaluate the performances of upflow vegetated fille, in removal of nutrients. The objectives of this study were two-fold: (i) to evaluate the nutrients removal performance of pilot-scale upflow vegetated filter, filled with a mixture of perlite and soil media and planted with cattails and (ii) to design of scale-up upflow vegetated filter using Froude number. Results indicated that, under the condition of the ranges of hydraulic surface load rate were $22.7{\pm}9.6\;m^3/m^2/day$, the average removal of $COD_{Mn}$, and TN, TP were 57.5%, 40.0% and 41.5%, respectively. Computational fluid dynamics, FLUENT 6.0 program was used to predict the distribution of velocity in UVF and hydrodynamic separator. Full scale UVF was designed using the Froude number scale-up method that was assumed geomertic similarity between model and prototype. Result shows that the UVF with 3 m diameter has capacity of design sewage flowrate 75 $m^3/day$.

• Journal of Cadastre & Land InformatiX
• /
• v.44 no.2
• /
• pp.155-175
• /
• 2014

This study targets to recognize needs of spatial pattern analysis and to draw the relationship between relocation of Capital Region firms and population outflow in Capital Region through the regression analysis. The population outflow in Capital Region has moved to and around Yesan-gun and Asan-si. Also, such outflow is found to compose mostly one or two household members for their jobs. In addition to this study has analyzed to find effect factors through the Geographically Weighted Regression. The results of the analysis has confirmed that the most decisive factors affecting population flow from Capital Region to Chungcheongnam-do were population factors and transportation factors and others. Thus, the below policy implications could be derived and also may be applied toward Sejong City which are currently experiencing the relocating of Public sectors and new constructions. Firstly, the effect of Capital Region firms movement on population inflows could be better observed in small-scale towns like "kun" than larger-scale towns like "si.". On the other hand, people in Capital Region moved to larger-scale towns like "si" unlike the Capital Region firms. This difference implicates that people select their residence according to not only their jobs but also residential environment. Secondly, moving people from Capital Region to another region for their jobs are expected to appear more in a form of family units rather than individual units. Sejong city, where public organizations are being relocated, should recognize this particular Chungcheonnam-do phenomenon and be prepared to be more effectively used in perspectives of land use as well as urban planning.

• Journal of Korean Society of Transportation
• /
• v.36 no.2
• /
• pp.86-97
• /
• 2018

City tour service has a function not only informs tourists of historical and cultural resources in the city but also contributes to improving city image making. In this study, a questionnaire was surveyed to tourists who used Suwon city tour to find out which factors make affect their intention to re-visit or recommendation to others. Structural equation model was constructed and set a hypothesis that overall city tour satisfaction would have a positive effect. The fitness of the final model was found out to be meet the statistical criteria. As a result of the final model, both satisfaction of guide and satisfaction of city tour operation were significant at 5% significance level (P<0.01). On the other hand, both satisfaction of bus facility and of promotion, customer service were statistically insignificant. Consequently, City tour service satisfaction was found to effect to the intention of re-visit and recommendation. Especially, The higher the satisfaction of guide and city tour operation, the more tendency to recommend. It is expected that local government which operates city tour bus could take advantage of this result in the future.