• Journal of Korean Society for Atmospheric Environment
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• v.28 no.1
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• pp.94-104
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• 2012

The purpose of this research is to quantify the compliance of on-road emission from a light duty diesel vehicle, based on a comparison to emission regulation standard. $NO_x$, CO and THC emissions were measured using a portable device on a selected real-world driving route with a length of approximately 22 km. On-road measurements were repeated by 10 times on a same route to reflect variability in traffic conditions. A test route was divided into 22 road links with length of 1 km to analyze emission results with higher spatial resolution. The average emissions of $NO_x$, CO and THC over total travel distance, which is approximately 220 km, were quantified to be in compliance with emission regulation standards. Under higher spatial resolution, $NO_x$ concentration exceeded a standard in 92 links out of 220 links. The extended time in stop period and the stop-and-go driving cycle were identified as two important reasons for increased $NO_x$ emissions in observed cases. Heavy traffics showed higher $NO_x$ emissions than free flow. These results indicate that the real-world vehicle emissions might exceed the compliance level associate with traffic conditions. Another interesting observation of this research is that the on-road emission characteristics can be independent to the average speed of road links with higher spatial resolution. Variability in on-road emission might not be fully described by solely relying on an average speed, because variability in traffic conditions and road conditions can influence on real-world vehicle emissions.

• Journal of Korea Game Society
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• v.11 no.5
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• pp.43-52
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• 2011

This study assumed the competitive structure based on genre classification for Korean online game market, and carried out the analysis on the degree and characteristics of the competition that appear differently in each sub market classified according to the genre. Analysis result can be summarized as follows. (1) In the view of the total play time, the proportions of the online games in each genre were appeared in the order of "RPG > FPS/RTS > Sports > Arcade/Poker > Go-stop > Board/Racing". (2) In the view of the shares in the play time, the degree of competition between games in the sub market structure of the online games according to the genre was found in the order of "RTS > Racing > FPS/Sports > Go-stop > Poker > Arcade/Board > RPG". The evaluation and interpretation of the high and low of the competition degree are as follows. As the degree of competition is higher, (RTS > Racing > ${\cdots}$) the royalty and the ratio of reusing of the users for the game is lower, and on the other hand, the tendency of replacing and using appeared higher, so the market entry barrier for a new game can be evaluated to be low. Reversely, as the degree of competition is lower, (${\cdots}$ > Arcade/Board > RPG) the royalty and the ratio of reusing of the users for the game is higher, and on the other hand, the tendency of replacing and using appeared lower, so the market entry barrier for a new game can be evaluated to be high.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.6
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• pp.2473-2481
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• 2013

The two characteristics of two-lane-and-two-way traffic flow are platoon and overtaking triggered by low-speed vehicle. It is crucial to develop a robust model which simultaneously generates the behaviors of platoon by low-speed vehicle and overtaking using opposite lane. Hence, a microscopic two-lane and two-way vehicle model was introduced (B. Yoon, 2011), which is based on CA (Cellular Automata) which is one of discrete time-space models, in Korea. While the model very reasonably explains the behaviour of overtaking low-speed vehicle in stable traffic flow below critical density, it has shortcomings to the overtaking process in unstable traffic flow above the critical density. Therefore, the objective of this study is to develope a vehicle model to more realistically explain overtaking process in unstable traffic flow state based on the model developed in the previous study. The experimental results revealed that the car-following model robustly generates the various macroscopic relationships of traffic flow generating stop-and-go traffic flow and the overtaking model reasonably explains the behaviors of overtaking under the conditions of both opposite traffic flow and stochastic parameter to consider overtaking in unstable traffic flow state. The vehicle model presented in this study can be expected to be utilized for the analysis of two-lane-and-two-way traffic flows more realistically than before.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.5
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• pp.1999-2007
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• 2013

The key characteristics of two-lane-and-two-way traffic flow are platoon and overtaking caused by low-speed vehicle such as truck. In order to develop two-way traffic flow model comprised of CF(car-following) and overtaking model, it is essential to develop a car-following model which is suitable to two-way traffic flow. Short distance between vehicles is caused when a high-speed vehicle tailgates and overtakes foregoing low-speed vehicle on two-way road system. And a vehicle following low-speed vehicle decides to overtake the front low-speed vehicle using suitable space within the headway distribution of opposite traffic flow. For this reason, a two-way CF model should describes not only running within short gap but also headway distribution. Additionally considering domestic two-way-road size, there is a on-going need for large-network simulation, but there are few studies for two-way CF model. In this paper, a two-way CA model is developed, which explains two-way CF behavior more realistic and can be applied for large road network. The experimental results show that the developed model mimics stop-and-go phenomenon, one of features of congested traffic flow, and efficiently generates the distribution of headway. When the CF model is integrated with overtaking model, it is, therefore, expected that two-way traffic flow can be explained more realistically than before.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.3 no.2 s.5
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• pp.75-83
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• 2004

July 1, 2004 Seoul Metropolitan city is operating the Median Bus Lane System on Gangnam Main Street, Seongsan-Susaek-ro (Road) and Dobong- Mia-ro (Road) as one of the systematic reorganizations in public transportation. It has been assumed that there was an improvement in the speed of bus considering that the Median Bus Lane System practiced on Cheonho-daero (Main Street) since 1996 have had 35km/h on the average. If the Median Bus Lane goes into effect, there is a problem with the left turn on the crossroad. The buses go on the existing first lane so that the left fuming cars cannot help but turn left on the second lane. In case that the Median Bus Lane is put into practice, the left turn on the crossroad should not be allowed. However, if the left turn is not permitted on the crossroads in the aforementioned main streets, neighboring residents will complain about it and there will be some difficulties in finding other detour. On the premise that the prevalent left turn on the crossroads is allowed while the Median Bus Lane is being put into practice, this study suggests the separation of a stop line between buses and other vehicles as a way of fuming left in a safe manner and a way to calculate the appropriate distance.

• Journal of Korean Academy of Nursing
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• v.25 no.2
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• pp.259-278
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• 1995

This study was done to investigate levels of physical fitness, self efficacy(SE), instrumental activities of daily living(IADL), and quality of life (QL), and their relationships among the elderly Data were collected from 47 noninstitutionalized elderly dwell-ing in their own homes and 43 institutionalized elderly living in homes for older people. The ages of the subjects were 65 years and over. The data were col lected from January 20th to February 20th, 1995. Physical fitness was measured with T.K. K dyna mometer, grip dynamometer, stop watch, and Purdue pegboard. Structured questionnaires developed by Kim by Lawton & Brody, and by Ro were adopted to measure SE, IADL, and QL, respectively. The data were analyzed using t-test, ANOVA, and Pearson correlation coefficients. The results were as follows : 1. The noninstitutionalized elderly had higher scores in such measures of physical fitness as body weight, skinfold thickness, flexibility and coordination as compared to the institutionalized elderly. 2. On the following measures of physical fitness, men showed higher levels than women ; in height when standing, height when sitting, body weight, and muscle strength. Women had more trunk flexibility than men. 3. Muscle strength was positively correlated with height when standing, height when sitting, and body weight. The following measures of physical fitness, muscle strength, flexibility and coordi nation, were negatively correlated with "up and go”. 4. The noninstitutionalized elderly had higher scores in SE(t=2.28, p<0.05), IADL(t=2.24, p<0.05), and QL(t=2.41, p<0.05) as compared to the institutionalized elderly. 5. SE was positively correlated with both IADL(r=0.41, p<0.001) and QL(r=0.54, p<0.001), and the latter two variables were a positively correlated (r=0.30, p<0.001). 6. SE was positively correlated with the physical fitness measures of height when standing, body weight, strength of leg muscles, strength of back muscles, grip strength, and level of touching the floor, but negatively correlated with "up and go”. 7. Positive correlations were revealed between IADL and the physical fitness measures of height, strength of leg muscles, level of trunk muscle extension, level of touching the floor, and coordination. The IADL was negatively correlated with “up and go”. 8. QL was positively correlated with body weight (r=0.28, p<0.01) and skinfold thickness (r=0.26, p<0.05). 9. Age was negatively correlated with the physical fitness measures of height when standing, height when sitting, “up and go”, strength of leg muscles, strength of back muscles, grip strength, level of trunk muscle extension, and coordination. 10. Age was also negatively correlated with SE (r=-0.24, p<0.05) and IADL(r=-0.22, p<0.05). The above results suggest that caring elderly in their own homes were more effective and that nursing interventions to enhance physical fitness, SE, IADL, and QL especially for the institutionalized elderly are stressed.

• The Journal of Korean Medical History
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• v.18 no.2
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• pp.55-62
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• 2005

In "Lingshu Benshen". five vicera are damaged due to changes in emotion having qi flow opposite to five viscera. As a result, it suggests that mental and physical illness could develop. The content of this piece can be explained in relation to five elements but uniformly through qi's flow. The contents can be summarized as follows. 1. The Heart is fire among the five elements and mainly characterized with dispersing. The flow of its qi is characterized facing upward and outward. On the other hand, being afraid or thinking seriously is characterized by making qi to go downward and stop so that the flow of qi is mainly facing toward inward and downward, damaging the heart. 2. The spleen has the conveyance function and spreads qi. On the other hand, worry and emotion inhibit qi function, blocking qi, damaging the spleen. 3. The liver has dispelling and removing functions and the power of sending up. The qi flow goes toward upward and outward. On the other hand, sadness stagnates qi, preventing the flow of liver's qi, damaging the liver. As a result, work is not done accurately. Madness develops with heat accumulated with qi stagnation. When qi is not sending up, mentality is not clear, leading to forgetfulness. 4. The lung has astringent and sending down functions, lowering qi. On the other hand, happy and joyful emotions bring up qi, showing the opposite flow of qi compared with the lung, damaging the lung. 5. The kidney has closing and storing functions, making qi flow to downward and inward. On the other hand, being angry makes qi to go up. Excessive expression of anger damages the kidney. As a result, the yin function of kidney does not work properly, leading to forgetfulness.

• Journal of the Korea Furniture Society
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• v.28 no.3
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• pp.248-258
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• 2017

A study was carried out to observe the 1% aqueous safranine solution flow speed in longitudinal and radial directions of softwood Thuja orientalis L., diffuse-porous wood Gmelina arborea Roxb., and ring-porous wood Phellodendron amurense Rupr., Longitudinal flow was considered from bottom to top while the radial flow was considered from bark to pith directions. In radial direction, ray cells and in longitudinal direction tracheids, vessel and wood fiber were considered for the measurement of liquid penetration speed at less than 12% moisture contents(MC). The variation of penetration speed for different species was observed and the reasons behind for this variation were explored. The highest radial penetration depth was found in ray parenchyma of T. orientalis but the lowest one was found in ray parenchyma of P. amurense. The average liquid penetration depth in longitudinal trachied of T. orientalis was found the highest among all the other cells. The penetration depth in fiber of G. arborea was found the lowest among the other longitudinal cells. It was found that cell dimension and also meniscus angle of safranine solution with cell walls were the prime factors for the variation of liquid flow speed in wood. Vessel was found to facilitate prime role in longitudinal penetration for hardwood species. The penetration depth in vessel of G. arborea was found highest among all vessels. Anatomical features like ray parenchyma cell length and diameter, end-wall pits number were found also responsible fluid flow differences. Initially liquid penetration speed was high and the nit gradually decreased in an uneven rate. Liquid flow was captured via video and the penetration depths in those cells were measured. It was found that even in presence of abundant rays in hardwood species, penetration depth of liquid in radial direction of softwood species was found high. Herein the ray length, lumen area, end wall pit diameter determined the radial permeability. On the other hand, vessel and fiber structure affected the longitudinal flow of liquids. Following a go-stop-go cycle, the penetration speed of a liquid decreased over time.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.8
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• pp.3677-3688
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• 2011

The patent information retrieval system can serve a variety of purposes. In general, the patent information is retrieved using limited key words. To identify earlier technology and priority rights repeated effort is needed. This study proposes a method of content-based retrieval using text mining. Using the proposed algorithm, each of the documents is invested with characteristic value. The characteristic values are used to compare similarities between query documents and database documents. Text analysis is composed of 3 steps: stop-word, keyword analysis and weighted value calculation. In the test results, the general retrieval and the proposed algorithm were compared by using accuracy measurements. As the study arranges the result documents as similarities of the query documents, the surfer can improve the efficiency by reviewing the similar documents first. Also because of being able to input the full-text of patent documents, the users unacquainted with surfing can use it easily and quickly. It can reduce the amount of displayed missing data through the use of content based retrieval instead of keyword based retrieval for extending the scope of the search.

• International Journal of Automotive Technology
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• v.4 no.2
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• pp.101-108
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• 2003

There are a lot of factors that influence automotive fuel economy such as average trip time per kilometer, average trip speed, the number of times of vehicle stationary, and so forth. These factors depend on road conditions and traffic environment. In this study, various driving data were measured and recorded during road tests in Seoul. The accumulated road test mileage is around 1,300 kilometers. The objective of the study is to identify the driving patterns of the Seoul metropolitan area and to analyze the fuel economy based on these driving patterns. The driving data which was acquired through road tests was analysed statistically in order to obtain the driving characteristics via modal analysis, speed analysis, and speed-acceleration analysis. Moreover, the driving data was analyzed by multivariate statistical techniques including correlation analysis, principal component analysis, and multiple linear regression analysis in order to obtain the relationships between influencing factors on fuel economy. The analyzed results show that the average speed is around 29.2 km/h, and the average fuel economy is 10.23 km/L. The vehicle speed of the Seoul metropolitan area is slower, and the stop-and-go operation is more frequent than FTP-75 test mode which is used for emission and fuel economy tests. The average trip time per kilometer is one of the most important factors in fuel consumption, and the increase of the average speed is desirable for reducing emissions and fuel consumption.