• Journal of Korean society of Dental Hygiene
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• v.8 no.4
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• pp.43-53
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• 2008

Some female college students have to recognize and understand the actual conditions of the tooth bleaching, and effective consultation and training to provide basic data for the purpose of investigation. this study made a survey about recognize and understand the actual conditions of the tooth bleaching and oral health knowledge and generalization methods for 649 female college student in Daejeon and Jeonbuk areas during the period between March. 15 and April. 10,2008. The results were as follows: 1. Tooth Status was found low, self-discontent respondents Status 44.2% and average 31.1%, self-contentment were 14.8%. Tooth color was average respondents were 69.8%, yellow 29.0%, White 1.7% (p=0.001, p=0.030). 2. Tooth bleaching experience has not experienced the most the military was 86.4%, to the desired Tooth bleaching for the external beauty 44.2%, confidence of smile time 37.5%. self-discontent 10.7%(p=0.000, p=0.000). 3. Tooth health status satisfaction was dental hygiene students higher than non dental hygiene, and scaling knowledge of the Tooth bleaching effect was non dental hygiene higher than non dental hygiene(p=0.039, p=0.000). 4. General knowledge for Tooth bleaching was found high 96.1%, as for the recognition route, 55.6% were through broadcast medium(p=0.025, p=0.000). 5. Medical institution chosen for Tooth bleaching treatment method appears the most preferred by 79.9% to the dental hospital dental clinic. 6. Important to consider that the choice of Tooth bleaching was Tooth bleaching duration of 37.1% cost 33%, And when Tooth bleaching hoped to be long-lasting. In this research the high recognized of Tooth bleaching treatment, but very low Tooth bleaching experience female college students for the Tooth bleaching had the wrong information. Therefore, Tooth bleaching treatment and counseling that can be used to development and education were required to provide the correct information.

• Journal of Korean society of Dental Hygiene
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• v.13 no.3
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• pp.395-401
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• 2013

Objectives : The purpose of this research was to investigate the awareness of an adult on implants and the relevant factors which affect the satisfaction of a patient after an implant treatment. Methods : This study was conducted to 407 adult subjects in Seoul and Gyeonggi. A total of 384 data were analyzed except the questionnaires having poor responses or errors. Results : The acquaintance route of implant was TV advertisements, self-knowledge, internet, news, and newspapers. Dentist's ability to practice implant was the most important factor in patient's choice. The responents answered the expected lifespan of an implant was more than 5 years to 10 years. In terms of dental health management behavior on implants, the average response of the highest 4.07 points of 5 Likert scale. Generally women are more concerned with implant than men(p<0.01). The highly educated and elderly patients had tendency to receive more treatment(p<0.0001). Patients were more satisfactory after receiving regular checkups after treatment(p<0.05). The low expenses of implant satisfied the patients(p<0.05). Conclusions : As implant technology advances, the concern of patients on implants also increase. So reduction of cost can make the patients have access to the dentist and the patients' oral health must be improved through continuous dental care.

• International Journal of Highway Engineering
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• v.9 no.3
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• pp.63-74
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• 2007

Traffic information provision plays an important role in increasing the efficiency of network operation and in providing convenience for roadway users. As a typical device for disseminating real-time traffic information for collective general public, VMS is a prevalent device nowadays and it is being expanded. However, the actual monetary value of traffic information is not quantified up to now. The previous studies regarding VMS traffic information are mainly focused on the behavioral aspects of road users such as departure time and route choices under traffic information provision conditions. This paper tried to estimate the monetary value of VMS traffic information using discrete choice theory and logit model through the stated preference study(SP). The methodological framework adopted in this paper can also be used in evaluating the monetary value of other traffic information providers including PDA, CNS, and mobile phone.

• Journal of Korean Society of Transportation
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• v.19 no.1
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• pp.77-88
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• 2001

Until now, though most of the studies related to demand estimation method using traffic counts use methods based on singleclass, travel demands or flows are made by mixing various vehicles in real networks. In general, existing demand estimation methods based on traffic counts estimate O/D by converting a multiclass O/D matrix and traffic counts into a singleclass O/D matrix and traffic counts through PCE conversion, and analyze a O/D matrix by dividing into a multiclass O/D matrix and traffic counts after multiplying an estimated O/D matrix by the fixed ratio of a singleclass O/D matrix and traffic counts before PCE conversion. However, the merits of a demand estimation method based on multiclass calculate each route choice ratio about multiclass O/D, and maximize the estimation capability of multiclass by calculating each gradient, the reduction direction of objective function. Therefore, this study aims to establish a demand estimation method which considers congestion between vehicle and vehicle by using multiclass instead of singleclass.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5D
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• pp.747-754
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• 2006

Real-time traffic information disseminated through VMS is known to have effects not only on driver to plan a route choice, detour the congestion, and cope with incident, but also on VMS operator to manage the traffic volume indirectly. But, the dissemination of traffic information is operated in the side of provider, not of user. Importance-Performance analysis (IPA) offers a simple, useful method for simultaneously considering both the importance and performance dimensions when evaluating or improving strategy. This technique has been successfully used in a variety of settings to define priorities and guide resource optimization decisions. This study uses IPA to evaluate traffic information strategies through VMS to make resource improvement recommendations. It gained 760 samples by field surveys, which are conducted in Korean Thanksgiving Day, weekday and weekend at the service areas of expressways. The results indicate that the motivations in quadrant I (concentrate here) are dissemination of exactly information and quick transmission, while distance of VMS, most drivers are not satisfied with that is located in quadrant III (low priority).

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.3D
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• pp.199-204
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• 2010

The purpose of this study is to estimate the effectiveness of newly proposed guide sign system. Existing guide sign system on expressways in South Korea have point-based system with city, district names or land marks. They have also several problems as excessive amount of information, low use of exit number, and lack of lane designation arrows. Efficiency of existing guide sign system is deteriorated from these problems. The enhanced guide sign system is proposed to alleviate problems. The best alternative sign system is chosen from three different designs with preference survey and human factors evaluation. The new signs showed reduced time compared to existing signs with statical significance. The existing sign system conveys more information in farther distance and less information in nearer distance. Nevertheless new systems imparts more information i nearer distance. It is also suggested that lane designation signs should be established with overhead installation at 0m point for efficient direction choice.

• Journal of the Korean Society of Radiology
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• v.83 no.6
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• pp.1240-1258
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• 2022

The lymphatic system provides a route for the spread of inflammation and malignancies. The identification of nodal stations and lymphatic pathways of tumor spread is important for tumor staging, choice of therapy, and the prediction of the prognosis of patients with malignant diseases. Because lymph node metastasis is common in primary intra-abdominal malignant tumors, its detection is essential for radiologists to understand the pattern of disease spread. Using schematic pictures and color-coded CT images, this pictorial essay describes the locations and nomenclature of the abdominal lymph nodes. Furthermore, the lymphatic drainage pathways of the upper and lower gastrointestinal tracts, liver, gallbladder, bile duct, and pancreas have been highlighted. In addition, lymph nodes belonging to the regional lymph nodes in malignant tumors arising from each organ are described, and certain cases are presented with images from patients.

• Journal of Korean Society of Transportation
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• v.22 no.5
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• pp.139-149
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• 2004

As the expansion of road capacity has become impractical in many urban areas, congestion pricing has been widely considered as an effective method to reduce urban traffic congestion in recent years. The principal reason is that the congestion pricing may lead the user equilibrium (UE) flow pattern to system optimum (SO) pattern in road network. In the context of network equilibrium, the link tolls according to the marginal cost pricing principle can user an UE flow to a SO pattern. Thus, the pricing method offers an efficient tool for moving toward system optimal traffic conditions on the network. This paper proposes a continuous network design program (CNDP) in network equilibrium condition, in order to find optimal congestion toll for maximizing net economic benefit (NEB). The model could be formulated as a bi-level program with continuous variable(congestion toll) such that the upper level problem is for maximizing the NEB in elastic demand, while the lower level is for describing route choice of road users. The bi-level CNDP is intrinsically nonlinear, non-convex, and hence it might be difficult to solve. So, we suggest a heuristic solution algorithm, which adopt derivative information of link flow with respect to design parameter, or congestion toll. Two example networks are used for test of the model proposed in the paper.

• Journal of Korean Society of Transportation
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• v.19 no.3
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• pp.101-113
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• 2001

Since late 1970s. one of the principal research areas in transportation problem is dynamic traffic assignment (DTA). Although many models have been developed regarding DTA, yet they have some limits of describing real traffic patterns. This reason comes from the fact that DTA model has the time varying constraints such as state equation, flow propagation constraint, first in first out(FIFO) rule and queuing evolution. Thus, DTA model should be designed to satisfy these constraints as well as dynamic route choice condition, dynamic user equilibrium. In this respect, link-based DTA models have difficulty in satisfying such constraints because they have to satisfy the constraints for each link, while path-based DTA models may easily satisfy them. In this paper we develop a path-based DTA model. The model includes point queue theory to describe the queue evolution and simulation loading method for depicting traffic patterns in more detail. From a numerical test, the model shows promising results.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.1
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• pp.71-78
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• 2018

Transportation is gradually changing into the era of V2X and autonomous cars. Accurate judgement of traffic conditions is an important indicator of route choice or autonomous driving. There are many ways to use probes car such as taxis, as a way to identify accurate traffic conditions. These methods may vary depending on the characteristics of the probe vehicle, and there is a problem with the cost. The V2X vehicle can solve these problems and collect traffic information in real time. If all vehicles are of V2X vehicle, these issues are expected to be resolved briefly. However, if the communication information of a V2X vehicle is represented by a traffic representative in a traffic with only V2X, the traffic information of some V2X vehicles will be able to collect traffic information. To accomplish this, a virtual network and transport were created and various scenarios were performed through SUMO simulations. It has been analyzed that 3-5 % of V2 vehicles are capable of representative the road traffic characteristics. In the future, various follow-up studies are planned.