• Journal of Korean Society of Transportation
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• v.28 no.6
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• pp.147-158
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• 2010

Studies on the distribution of traffic demands have been proceeding by providing traffic information for reducing greenhouse gases and reinforcing the road's competitiveness in the transport section, however, since it is preferentially required the extensive studies on the driver's behavior changing routes and its influence factors, this study has been developed a discriminant model for changing routes considering driving conditions including traffic conditions of roads and driver's preferences for information media. It is divided into three groups depending on driving conditions in group classification with the CART analysis, which is statistically meaningful. And, elements of the driving conditions and the preferred media affecting the change of paths are classified into statistical meaningful groups through the CHAID analysis, and the major factors affecting the change of paths are examined. Finally, the extent that driving conditions and preferred media affect a route change is examined through a discriminant analysis, and it is developed a discriminant model equation to predict a route change. As a result of building the discriminant model equation, it is shown that driving conditions affect a route change much more, the entire discriminant hit ratio is derived as 64.2%, and this discriminant equation shows high discriminant ability more than a certain degree.

• Archives of Reconstructive Microsurgery
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• v.5 no.1
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• pp.121-127
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• 1996

Peripheral nerve injury occurs mostly by trauma and is usually associated with fracture of bone and joint, muscular injury and tendon injury and it also evokes paralysis and anesthesia. When treatment of peripheral nerve injury is considered,, the modality of treatment is decided by the general condition of the patient, type of injury, associated injuries and the condition of wound. To get the maximum results, surgical treatment and reconstruction and rehabilitation should all go in hand-in-hand. From January 1985 to December 1994, we observed 61 patients that had operation without reconstruction due to peripheral nerve injury with a follow-up period of more than 1 year. Among the 61 patients, 44 were men(72%) and 17 were women(28%). Follow-up period was average 19 months. Age distribution was mostly in their twenties with a mean age of 28 years. Time interval of operation after injury was average 11 months. Trauma was the main cause of peripheral nerve injuries with a proportion of 87%. 31 patients had neurorrhaphy, in which case 14 patients had stay suture and 17 patients did not. 14 patients had nerve graft, and 16 patients had neurolysis. We used our scales to compare the results of surgery on the basis of British Research Council System. We gave scores to every sensory and motor scale to estimate functional improvement and emphasized on motor functional improvement. The total score = sensory score + ($2{\times}motor$ score). We considered 8-9 points as excellent, 6-7 points as good, 2-5 points as fair, 0-1 points as poor result. We considered excellent and good as much improved. Excellent and good results were obtained in 13 out of 14 neurorrhaphy with stay suture(93%), 12 out of 17 neurorrhaphy without stay suture(71%), 6 out of 14 nerve graft(43%), 12 out of 16 neurolysis(75%). Among the patients with neurorrhaphy done within 3 months, 11 out of 14(86%) showed improvement, but among the patients after 4 months 3 out of 17(76%) showed improvement. 84% of improvement was observed in the patients with time interval from injury to surgery within 3 months, and 64% in the patients with time interval after 4 months. In the aspect of age, 77% with the age below 20 years, 70% with the age between 21 and 30 years, 66% with the age above 31 years showed improvement. We conclude that considering degree of injury, time interval from injury and age with the adequate method of treatment, we can obtain good results from surgery.

• Journal of Nutrition and Health
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• v.28 no.7
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• pp.653-674
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• 1995

This study was aimed at comparing the dietary patterns of university female students according to their residence type. As for subjects, one hundred and twenty students of Kongju national university were chosen as a total. They were devided into three groups ; those who live in family home, or university dormitory, or self-boarding house. In this study, intakes of food and nutrient and dietary behaviors of each group were investigated through two-day food records and questionnaire. The result was that mean daily intakes of calcium and iron were lower than RDAs in all groups. According to residence type, subjects of family home and self-boarding seemed to have more serious problem in the nutrients mentioned above considering the proportions of less than 2/3 of RDAs. Especially, iron status was poorer than any other nutrients in the aspects of this proportion and food source. Iron was taken largely from vegetable foods which were recognized as a source of low bioavailability of iron. The average distribution ratios of breakfast, lunch, dinner and snack to total calorie intake was 22, 29, 30 and 19. Thus, it proved that breakfast tended to be more negligent than any other meals, and that snack was an important means to give nutrients for subjects. This meal pattern might be one of the factor for the decrease of the dietary quality. Processed foods were founded to be an important source for providing nutrients. Percentages of calorie, carbohydrate and fat consumed by processed foods to total nutrients. Percentages of calorie, carbohydrate and fat consumed by processed foods to total nutrients intake were 30.6, 29.5 and 46.2. However, other nutrient intakes from processed foods such as vitamin and mineral were small. And processed foods which give nutrients were mainly cereal products like ra myon, bread, and milk and milk products. Consequently, processed foods seemed to be selected as a combinient substitute food which supply calorie to fill their hunger. According to the living type, dormitory students had them more frequently than any other groups. Food habit score was within the category of poor or fair. Particularly, the score of self-boarding students was the lowest of groups(p<0.05). The major dietary problems were small or overating, missing meal and irregular eating. The degree of these problems was a little different among groups(P<0.01). Nineteen kinds of food were consumed per day, and family home and self-boarding students had foods less variously than dormitory students(P<0.05). Proportions of skipping breakfast, lunch and dinner were 20.8, 12.5 and 8.3%. Accordingly, breakfast was missed more often than any other meals. And self-boarding students missed breakfast more often than any other groups. As a conclusion, subjects should take more calcium and iron, and eat diverse foods to improve their nutritional status. And it is also necessary that breakfast should be regarded more importantly, and that processed foods should be taken considering nutritional balance. In view of residence type, subjects of family home or self-boarding had more dietary problems than dormitory subjects. Thus, these results suggest that university female students might have low ability of meal management, and dietary patterns were different by their residence type. Therefore, nutrition education for them should be carried out with respect to dewelling environment.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.17 no.1
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• pp.21-30
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• 2004

This study deals with free vibrations of laminated composite structures with a channel section using finite element method. In this paper, the mixed finite element method using Lagrangian and Hermite interpolation functions is adopted and a high-order plate theory is used to analyze laminated composite non-prismatic folded plates with a channel section more accurately for free vibration. The theory accounts for parabolic distribution of the transverse shear stress and requires no shear correction factors supposed in the first-order plate theory. An 32×32 matrix is assembled to transform the system element matrices from the local to global coordinates using a coordinate transformation matrix, in which an eighth drilling degree of freedom (DOF) per node is appended to the existing 7-DOF system. The results in this study are compared with those of available literatures for the conventional and first-order plate theory. Sample studies are carried out for various layup configurations and length-thickness ratio, and geometric shapes of plates. The significance of the high-order plate theory in analyzing complex composite structures with a channel section is enunciated in this paper.

• Asia pacific journal of information systems
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• v.17 no.4
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• pp.97-112
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• 2007

Most traditional newspaper publishers provide online editions to counter the competition of online news providers. However, the relationship between the online and print editions of the same newspaper has not been clearly defined. Some see the online newspaper as a substitute, while others consider it a complement. A 2002 NAA online newspaper consumer survey indicated that one-third of its respondents said they were now using the print newspaper less. Others have argued that the online edition will not wipe out print consumption, and may even complement it. While the print edition offers particular advantages such as portability, less eye strain, and the tactile experience of a printed page, the online edition also offers specific advantages such as access to breaking news, continually updated information, access to old archives, etc. All these factors would tend to lower the degree of interchangeability between the products. However, recent empirical studies show that the online edition is a substitute for rather than a complement of the print edition. Still, to some print readers, the online edition provides additional value. In this paper, by capturing the two different aspects of online editions the substitute aspect and the additional value added aspect as well as other available online alternatives, we develop an analytical model to derive the optimal production and distribution strategies of both online and print editions. Confronting the "free versus fee" issue, we show that it is optimal to provide an online version of the print newspaper for free to non-print subscribers. However, the amount of free news content that the publishers need to put on the Web depends on the available alternatives on the online market. The "fee" and "free" options both have merits and demerits as well. If the publisher charges for the online version of the print newspaper, she can generate revenue from the fee charged to online readers. However, doing so will limit the size of the online audience and further reduce online advertising revenue. At the same time, by providing a high-quality online version and charging for it, the price of the print newspaper must stay low in order to lure high valued readers. On the contrary, if the publisher provides an online version of the print newspaper for free, she can obtain a larger audience for the online version. At the same time, by providing a low-quality online newspaper, the publisher can increase the print newspaper price to get more revenue from high valued offline readers, although no revenue is incoming from online version readers. Through systematic measuring of all the pros and cons, our analysis shows that the optimal option is not "fee" but "free."

• Journal of the Korean Electrochemical Society
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• v.11 no.2
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• pp.89-94
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• 2008

We synthesized and investigated $(La_{0.75}Sr_{0.25})_{1-x}FeO_{3-\delta}$ perovskite oxides having different stoichiomety (x = 0, 0.02, 0.04, 0.06, 0.08) as cathode materials. SEM images and XRD patterns reveal that the synthesized powder has uniform size distribution and high degree of crystallinity. The electrochemical performances of the synthesized powders were investigated by AC impedance spectroscopy. Both the electric conductivity and the electrochemical performance showed the highest properties at the stoichiometry x = 0.02. Finally, we concluded that the variation of A-site deficiency results in the variation of the amount of oxygen vacancy and micro structure, which leads to the variation of electric conductivity and polarization resistance.

• Journal of Global Scholars of Marketing Science
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• v.8
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• pp.61-87
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• 2001

Internet, which has been developed as a new exchange revolution, forms a huge virtual exchange market, and the innovative electronic commerce has completely broken off the way of existing goods distribution. This study begins with an awareness of the importance of customer retention to keep winning over the competition in internet shopping mall. In order to explain of the customer retention between individual and internet shopping mall, the study introduces first a satisfaction on shopping followed by an awareness of the importance of customer retention, and looks into a formation process of trust, satisfaction, and relationship orientation occurred by the offer of valuable convenience to customers. The study also explores the influence on shopping value by the characteristics with which internet shopping mall can bear, unfold by a cause and effect relationship the degree of shopping satisfaction, trust, and relationship orientation, and inquires a question to find out how to fuse the characteristics for internet retention. Therefore, this study has the following purposes: After examining prior research for the characteristics of internet shopping mall, it presents a possibility to connect shopping value with customer retention in light of theoretical system on characteristic elements derived from emotional and utilitarian perspectives. In order to achieve the purposes, the characteristics of internet retailing shop included site design, virtual reality, web awareness, customer concern, merchandise search, information supply, product value, and transaction system. Hypotheses were set up for the relationship with these characteristics and substantially analyzed. To prove this research, we analyzed collected data in which customers had experienced in shopping at internet shopping mall and discussed strategic current issues about its analytic results.

• The Korean Journal of Ecology
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• v.16 no.3
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• pp.239-259
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• 1993

The vegetation types and distributional characteristics of the forest vegetation on Mt. Ilwol were investigated by the Z-M school method. Geographical distribution of the vegetation was a central/montane(CEMO) type of the Korean Peninsula subtype. The forest was classified into five vegetation units: Artemisio-Quercetum mongolicae (Artemisio-Quercetum typicum subass. nov., Artemsio-Quercetum pinetosum dens~florae subass. nov. ). Lychno-Quercetum mongolicae (Lychno-Quercetum Calamagrostetosum arundinaceae subass. nov.. Lychno-Quercetum ligularetosum f~scherii subass. nov.), Fraxinus rhynchophylla community, Quercus variabilis community and Larix leptolepis afforestation. Species with percentage constance degree more than 61% are Quercus mongolica (89.5%, V), Lespedeza maximowiczii (73.7%, IV), Isodon japonicus(73.7%, IV), Fraxinus rhynchophylla (68.%, IV), Arlemisia stolonifera (65, 8%, IV), etc. Artemisio-Quercetum mongolicae was chiefly distributed on the ridge lines of low altitudes (570~700m) and on the ground with exposed rocks in sloping surface (800~1, 000m). Both Fraxinus sievoldiana and Rhododendrou schlippenbachii of the Artemisio-Quercetum mongolicae showed a predominant condition all over the subtree and shrub layers. Of Artemisio-Quercetum pinetosum densifloraes, Pinus densiflora becomes powerful over the tree layer and, on the other hand, Quercus mongolica over the subtree layer. Lychno-Quercetum mongolicae was distributed somewhat on the humid region of the high altitude area (840~1.200m). Fraxinus rhynchophylla community was chiefly distributed in the vicinity of the ravines. Quereus rariabilis community was distributed at subxeric slope on southeast side of the mountain. Larix leptolepis has been reforested at the ecotone between Artemisio-Quercetum mongolicae and Lychno-Quercetum mongolicae. Percentage cover degrees of the subtree layer In Lychno-Quercetum mongolicae, Quereus rariabilis community and Larix leptolepis afforestation were relatively low, 15.3%, 5% and 2.5%, respectively.The contents of moisutre and organic matter in the soil were much higher in Luchno-Quercetum monogolicae and Larix leptolepis afforestaion than in the other communities. Contents o Ca, Mg, K and the available phosphorus were relaively high compared with forests of the other area. This result seems to be influenced by a forest fire. As the altitude increases, the moisure content in the forest soil also increases.

• The KIPS Transactions:PartD
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• v.9D no.5
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• pp.755-768
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• 2002

We investigate the effect of the data skew of join attributes on the performance of a pipelined multi-way hash join method, and propose two new hash join methods with load balancing capabilities. The first proposed method allocates buckets statically by round-robin fashion, and the second one allocates buckets adaptively via a frequency distribution. Using hash-based joins, multiple joins can be pipelined so that the early results from a join, before the whole join is completed, are sent to the next join processing without staying on disks. Unless the pipelining execution of multiple hash joins includes some load balancing mechanisms, the skew effect can severely deteriorate system performance. In this paper, we derive an execution model of the pipeline segment and a cost model, and develop a simulator for the study. As shown by our simulation with a wide range of parameters, join selectivities and sizes of relations deteriorate the system performance as the degree of data skew is larger. But the proposed method using a large number of buckets and a tuning technique can offer substantial robustness against a wide range of skew conditions.

• The KIPS Transactions:PartB
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• v.15B no.5
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• pp.457-464
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• 2008

In the real-world operational environment, most of text classification systems have the problems of insufficient training documents and no prior knowledge of feature space. In this regard, $Na{\ddot{i}ve$ Bayes is known to be an appropriate algorithm of operational text classification since the classification model can be evolved easily by incrementally updating its pre-learned classification model and feature space. This paper proposes the improving technique of $Na{\ddot{i}ve$ Bayes classifier through feature weighting strategy. The basic idea is that parameter estimation of $Na{\ddot{i}ve$ Bayes considers the degree of feature importance as well as feature distribution. We can develop a more accurate classification model by incorporating feature weights into Naive Bayes learning algorithm, not performing a learning process with a reduced feature set. In addition, we have extended a conventional feature update algorithm for incremental feature weighting in a dynamic operational environment. To evaluate the proposed method, we perform the experiments using the various document collections, and show that the traditional $Na{\ddot{i}ve$ Bayes classifier can be significantly improved by the proposed technique.