• The Journal of the Convergence on Culture Technology
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• v.6 no.2
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• pp.529-534
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• 2020

The development of civilization is in line with evolution of cities and transportation technology caused by industrialization. Up to now, a city has been developed owing to transportation cost reduction and needs for land utilization as a limited core business district. Continuous increase of urban population density has accompanied by lots of problems socioeconomically such as rise of land value, traffic congestion, gap between the rich and poor, air pollution, etc. Those issues are difficult to be solved in existing city ecosystem. However, a clue for solving the problems could be found in there. The design of Seoul mid-night bus route was from analysis of movement of people in the rural area by using ICT so that a city ecosystem should be firstly analyzed for solving rural issues. If the cause of those is found, big data platform construction is required to raise the life quality of citizen and the problems could be solved. Big data should be located in the middle of the platform connected with every element of city based on ICT for real-time collection, analysis and application. This paper addresses construction of big data platform and its application for sustainable smart city.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.2
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• pp.85-102
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• 2021

Phytosociological characteristics on Quercus acutissima forests distribution in Daechong-dam basin survey has been carried out using Z.-M. School's methodology and numerical-classification analyses. A total of 43 phytosociological relevés were sampled. Syntaxa were described as Oplismenus undulatifolius-Quercus acutissima community(typicum subcommunity, Phryma leptostachya var. asiatica subcommunity, Ulmus davidiana var. japonica subcommunity), Quercus acutissima community and Quercus variabilis-Quercus acutissima community (typicum subcommunity, Castanea crenata subcommunity). The above three plant communities were classified with species composition reflecting local environmental characteristics of mountain topographies, inclination degrees, and rock exposure rates. Conclusively, those communities were recognized as secondary vegetation affected by high intensity and frequency of human impacts as they inhabited in southward hill lands and low lying grounds in mountains adjacent to human settlements and arable lands. Quercus acutissima community was classified as rural type syntax based on their inlandward distribution and species composition differences from urban forests. Afforest process and natural succession were discussed in relation with habitat environmental elements of Quercus acutissima forest in the survey area.

• KEPCO Journal on Electric Power and Energy
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• v.8 no.2
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• pp.103-110
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• 2022

Ultrafine Particle number and size distributions were simultaneously measured at rural area around the power plant in Dangjin, South Korea. New Particle formation and growth events were frequently observed during January, 2021 and classified based on their strength and persistence as well as the variation in geometric mean diameter(GMD) on January 12, 21 and 17. In this study, we investigated mechanisms of new particle growth based on measurements using a high resolution time of flight aerosol mass spectrometer(HR-ToF-AMS) and a scanning mobility particle sizer(SMPS). On Event days(Jan 12 and 21), the total average growth rate was found to be 8.46 nm/h~24.76 nm/hr. These growth rate are comparable to those reported for other urban and rural sites in South Korea using different method. Comparing to the Non-Event day(Jan 17), New Particle Growth mostly occurred when solar radiation is peaked and relative humidity is low in daytime, moreover enhanced under the condition of higher precusors, NO₂ (39.9 vs 6.2ppb), VOCs(129.5 vs 84.6ppb), NH₃(11 vs 4.7ppb). The HR-ToF-AMS PM_1.0 composition shows Organic and Ammoniated nitrate were dominant species effected by emission source in domestic. On the other hand, The Fraction of Ammoniated sulfate was calculated to be approximately 16% and 31% when air quality is inflow from China. Longer term studies are needed to help resolve the relative contributions of each precusor species on new particle growth characteristics.

• Journal of the Korean Institute of Rural Architecture
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• v.24 no.2
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• pp.21-28
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• 2022

Focusing on the creation of a new han ok, especially a mid-rise hybrid-structured Han-ok, this study proposes a middle-rise (four-story) Han-ok on one and two lots located in Seoun-dong, the existing Han-ok intensive housing site in downtown Cheongju. 1) In terms of layout and function, according to the existing L-shaped Han-ok corresponding to the road and the direction, the parking lots and shops on the 1st floor, the business facility on the 2nd floor, the Han-ok on the 3rd and 4th floors are placed. There are yards, open roof yards, and semi-open Daecheong(大廳, main hall), which can be shared by residents. 2) In terms of structure and form, one or two floors (some 3 floors) are 5.4m square and 5.4×6.6m modules of the RC(Reinforced Concrete) group, and the upper floor reflects the 2.7m module, size and shape of the existing Han-ok. By extending the outer wall of the RC group in the lower floors (1st to 3rd floors) to the wooden exterior of the upper floors (2nd to 4th floors), it is attempted to avoid the awkward appearance of the RC group being exposed to wooden structures. And it is also attempted to reflect the wooden shape and design elements through the elevation elements such as horizontal windows, corner windows, picture frames, and vertical slits. 3) In environmental control and facilities, it is attempted to smooth the ventilation of the building by forming a vertical upward airflow from the dark space of the low floor to the positive of the upper floor. This doubles the effect through a vertical rise of cold air generated in a narrow alleyway, piloti parking lot, and the various voids. In addition to the Daecheong and Numaru(loft) of Han ok, the rooftop yard, the terrace, and the balcony, horizontal natural ventilation is generated through divided doors and transom windows.

• Geomechanics and Engineering
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• v.35 no.5
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• pp.511-523
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• 2023

Canal-side roads frequently collapse due to an unexpectedly greater soft-clay thickness with a rapid drawdown situation. This causes annually increased repair and reconstruction costs. This paper aims to explore the effect of soft-clay thickness on the failure in the canal-side road in the case study of Phra Nakhon Si Ayutthaya rural road no. 1043 (AY. 1043). Before the actual construction, a field vane shear test was performed to determine the undrained shear strength and identify the thickness of the soft clay at the AY. 1043 area. After establishing the usability of AY. 1043, the resistivity survey method was used to evaluate the thickness of the soft clay layer at the failure zone. The screw driving sounding test was used to evaluate the undrained shear strength for the road structure with a medium-stiff clay layer at the failure zone for applying to the numerical model. This model was simulated to confirm the effect of soft-clay thickness on the failure of the canal-side road. The monitoring and testing results showed the tendency of rapid drawdown failure when the canal-side road was located on > 9 m thick of soft clay with a sensitivity > 4.5. The result indicates that the combination of resistivity survey and field vane shear test can be successfully used to inspect the soft-clay thickness and sensitivity before construction. The preliminary design for preventing failure or improving the stability of the canal-side road should be considered before construction under the critical thickness and sensitivity values of the soft clay.

• Journal of Korean Society of Water and Wastewater
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• v.37 no.6
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• pp.363-373
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• 2023

Numerous studies have established a correlation between sociodemographic characteristics and water usage, identifying population as a primary independent variable in mid- to long-term demand forecasting. Recent dramatic sociodemographic changes, including urban concentration-rural depopulation, low birth rates-aging population, and the rise in single-person households, are expected to impact water demand and supply patterns. This underscores the necessity for operational and managerial changes in existing water supply systems. While sociodemographic characteristics are regularly surveyed, the conducted surveys use aggregate units that do not align with the actual system. Consequently, many water demand forecasts have been conducted at the administrative district level without adequately considering the water supply system. This study presents an upward water demand forecasting model that accurately reflects real water facilities and consumers. The model comprises three key steps. Firstly, Statistics Korea's SGIS (Statistical Geological Information System) data was reorganized at the DMA level. Secondly, DMAs were classified using the SOM (Self-Organizing Map) algorithm to consider differences in water facilities and consumer characteristics. Lastly, water demand forecasting employed the PCR (Principal Component Regression) method to address multicollinearity and overfitting issues. The performance evaluation of this model was conducted for DMAs classified as rural areas due to the insufficient number of DMAs. The estimation results indicate that the correlation coefficients exceeded 0.9, and the MAPE remained within approximately 10% for the test dataset. This method is expected to be useful for reorganization plans, such as the expansion and contraction of existing facilities.

• Korean journal of food and cookery science
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• v.11 no.4
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• pp.370-378
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• 1995

This study is to seek methods for optimum management of foodservice system for elementary schools in Korea through surveying and analyzing the current status of the "common-management foodservice system" and certain important factors relating to its operations. For the survey of the current status of the "common-management foodservice system", questionnaires are prepared as against schools adopting "common-management system"("Common Schools") as well as schools adopting "conventional management system" ("Conventional Schools") in Kyungsangbookdo ("Kyungbook") area. The survey items are composed of general items, items concerning tasks of dietitians, items concerning purchasing activities and items concerning level of recognition and job-satisfaction of the dietitians. Total 46 dietitians from Common Schools and 65 dietitians from Conventional Schools in Kyungbook region responded the questionnaires. The results of this study are as follows: 1. Information Concerning Dietitians Average age of the dietitians: 26.6 yrs Ratio of two years or less of experiences as school dietitian: Dietitians from Common Schools: 59.1％ Dietitians from Conventional Schools: 50.8％ 2. Types of the Foodservice In both schools, rural type are prevalent; however, between urban types and islands types, the ratio of urban types are larger than the ratio of islands types in Conventional Schools, and the opposite is true in Common Schools. 3. Decision of Suppliers The ratio of dietitian＇s participaion in the decision making reaches only 38.3％, indicating the possibility of problems in quality control and hygienic aspects of the food supply. 4. Factor Analysis of the Foodservice Duties Food supply and general affairs administration work was carried out very well (4.2), while personnel management and operational improvement work (2.8), nutritional education work (2.3), and information related work were poorly carried out. No significant differences were found between the two types of the foodservice management systems. 5. Job Satisfaction scores of Dietitians Dietitians were more satisfied with the works (50.0), supervision (50.5) and co-workers (46.9) than pay (18.0) and promotion (22.3).

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.6
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• pp.123-134
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• 2013

Strengthening vehicle emission regulation is one of important policies to improve air quality in urban area. Due to the limitation of specified driving cycles for certification test to reflect real driving conditions, additional off-cycle emission regulations have been adopted in US and being developed in Europe. The driving cycles of US or Europe have been used in emission certification for Korean light-duty vehicles, but it has not been known how well the driving cycles reflect various real driving patterns in Korea. In that point of view, it is required to estimate vehicle emission based on real road driving conditions to raise the effectiveness of vehicle emission regulation in Korea. In this study, real driving emission measurements have been conducted for three Korean light-duty vehicles with PEMS. The driving routes consisted of urban, rural and motorway in Seoul and Incheon. The data have been analyzed with various averaging methods including moving averaging windows method and compared to emission limits set with emission certification modes applied to tested vehicles. The results have shown that the real driving pollutant emissions of a gasoline and a LPG vehicles have been ranged quite lower than those of emission limits on CVS-75 driving cycle. But real driving NOx of a light duty diesel vehicle has been considerably higher than emission limit of NEDC driving cycle. The higher than expected NOx emission of a diesel vehicle might be caused by different strategy to control EGR in real driving condition from NEDC driving.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.2
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• pp.47-55
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• 2003

In this paper, the performance of DS-CDMA system with smart antenna is analyzed for different bandwidths (1.25MHz,5MHz) and different channel environments (rural, urban) in wideband multipath channel. For the analysis of smart antenna system, the vector channel having the spatio-temporal correlation is modeled as a time-variant linear filter in time, and each multipath is assumed as a reflective wave from only one direction (only one cluster) in space. Several multipath is within one chip are distingushed into each one and the strongest signal is selected, DS-CDMA system with smart antenna using wider bandwidth present better performance than that using narrow bandwidth. It is shown that the smart antenna is more effective in urban area when using 2D-RAKE receiver.

• Land and Housing Review
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• v.8 no.4
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• pp.223-232
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• 2017

The purpose of this study is to identify the supply status and planning trend of North Korean housing through analysis on the North Korean architecture specialized media data. The flat composition is changing and the living room is becoming the center of the houses. Also, in the urban areas, the standard apartment type is four apartments in a row and the plan form is getting diversified into circle type, Y type, and irregular type. On the other hand, in the rural areas, two houses in a row and single house are typical and the change in planning scale and space structure are not substantial. Since the 2000s, design changes have been made to emphasize the third dimensional structure of buildings such as the elliptical houses and L-shaped houses. Furthermore, 8~10 households are located on one floor which leads to the tendency of the building enlargement. In terms of house size, a square concept was introduced to replace the initial 2~3 room concept and the basic module of the room planning the 3 room house based on $3m{\times}3m$. However, there seems to be no standard house size, and the house size may differ depending on the social classandregion. In the early 1980s, when there was focus on the apartment complex construction, the high-rise apartment buildings of 30~40 floors was planned. However, during the Pyongyang redevelopment project, apartments of more or less than 10 floors were built and row-houses of more or less than 4 floors were built. In terms of the complex scale, a lot of small complexes of around 300 households are emerging after 2010. The construction projects are mainly limited to specific regions such as Pyongyang and Samjiyeon, and also limited to specific classes such as the workers and soldiers initially and the scientists lately. In addition, living boundary composition and ancillary facilities for sufficient green area ratio securement and the people of North Korea are maintained consistently. In recent years, the specialized floor planning such as solar house and the house for the disabled people, framework houses for redevelopment business, and multi-storied house construction technology are also emerging.