• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.1
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• pp.575-580
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• 2014

The liquid crystalline copolymers were synthesized through direct polycondensation using 4-[4-(4-hydroxyphenoxy)butoxy]benzoic acid (HBBA) and p-hydroxy benzoic acid (HBA) as monomers. The structure and properties for synthesized copolymers were investigated by $^1H$-NMR, FT-IR, differential scanning calorimetry (DSC), thermogravimetry analysis (TGA) and polarizing optical microscope (POM). As result of investigations, inherent viscosities (${\eta}_{inh}$) of polymers were measured as 0.77~1.60 dL/g in phenol/p-chlorophenol/1,1,2,2-tetrachloroethane (25/40/35=w/w/w). Except for P-80, the ranges of the transition and mesophase temperature of copolymers were increased with increasing the amount of HBA. These properties of polymers were presumably due to increasing of the irregularity and rigidity of polymer chains.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.6
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• pp.2575-2582
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• 2013

In the delivery systems for public construction works, design-build methods such as turn-key and alternative have contributed to improving the quality of structures and developing the construction technology. However, it is pointed out that construction based on a design-build method is likely to waste a budget due to its higher contract price than construction based on a design-bid-build method. Other issues such as contract monopoly, bid rigging and deliberation irregularity in design-build. Since there are not much works have been accomplished to comparatively analyze the actual performance and effect based on delivery methods, discussing and judging the performance and effect of each deliver method with limited information could lead to an error. Thus, this study by extensively investigates the actual project cost data, ranging from contract price to the construction cost of the public construction works and comparatively analyzed the characteristics of each delivery method about cost structure and fluctuation trend. This work is expected to assist stake-holders in properly understanding delivery systems for public construction works and promoting their efficient management.

• Journal of the Korean Society for Railway
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• v.15 no.6
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• pp.623-630
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• 2012

Formation used as trackbed foundation for providing vertical bearing capacity onto rail foundation are composed of crushed stones usually with certain type of grain size distribution. Permanent deformation in trackbed foundation can be generated by increasing number of load repetition due to train traffic increases, causing track irregularity. In this study, a specially prepared trackbed foundation materials (M-40) used in Korea has been tested using a large repetitive triaxial compression apparatus in order to understand resilient and permanent deformation characteristics of the material. From these test results, resilient and permanent deformation characteristic are analyzed so that a permanent deformation model is developed which can consider number of load repetition N, confining stress (${\sigma}_3$), shear stress ratio(${\tau}/{\tau}_f$) and stiffness of the material.

• Journal of Korean Dental Science
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• v.6 no.2
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• pp.87-95
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• 2013

Synovial chondromatosis (SC) is a rare, benign disease found in metaplastic cartilaginous nodules within the synovial membrane. The etiology of SC is not well-known, but it may be associated with trauma, chronic abnormal loading, or inflammatory joint disease. It is often found in knee, elbow, ankle, and shoulder joint but rarely in the temporomandibular joint (TMJ) area. SC of TMJ frequently appears in middle age and more often in females. Clinical symptoms include periarticular swelling, pain, crepitus, and limitation of joint motion. The most common feature is a radiographic finding of loose bodies in the joint. Irregularity of joint space and condylar head is also observed. Treatment involves the surgical removal of synovium and loose bodies. The prognosis is good, with low postsurgical recurrence rate. Functional improvement of the joint and pain relief are noted in many patients. Malignant transformation of SC has not been recorded. In this study, we report a 54-year-old female patient who experienced discomfort on the right TMJ with SC on the area but made a satisfactory recovery after surgery.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.1
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• pp.53-61
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• 2018

Ballast track requires constant maintenance work due to progress of track irregularity. Fast Hardening Track(FHT) has been developed to reduce the maintenance effort done by injecting fast hardening mortar in aged ballast to convert slab track. For the application of FHT to a railway bridge, post-installed anchors should be placed at center of the track segment to fix it on bridge. This paper presents track-bridge interaction analysis results with FHT considering stiffness and strength of post-installed anchor, age of FHT concrete and friction between FHT and bridge deck surface. Based on the analysis results, this study suggests when is good to install the anchors and allow normal operation of passing train.

• Journal of the East Asian Society of Dietary Life
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• v.13 no.3
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• pp.155-166
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• 2003

This study was conducted to investigate the dietary behavior and health-related lifestyles of university students in Incheon arear Self administered questionnaires were collected ken 179 food and nutrition major and non-major students. Statistical data analysis was completed using a SPSS v.10.0 program. The results are summarized as follows: The average weight, height, BMI and PIBW of the major and non-major male and female students were 69.89kg, 172.89cm, 23.4 and 106.49 ; 67.27kg, 173.98cm, 22.2 and 101.35 ; 50.61kg, 161.20cm, 19.53 and 92.25 ; 53.77kg, 161.53cm, 20.56 and 97.18, respectively. The breakfast skipping ratio of the subjects were very high, which was mainly due to the reason“lack of time”More than 75% of male students and 61% of female students responded to have lunch at university canteens or restaurants around campus regularly. About 56% of male students and 68% of female students responded to have dinner irregularly, which mainly caused by the reasons“irregularity of lecture”and “appointment with friends”. The ratio of snacks intake of the subjects were high; Ramyun was the snack item taken the most by the male students and fruits and cookies by the female ones. More than 50% male students and 2% of female students were smokers. A half of students dunk alcohol once or twice a week. The dietary behaviors and health-related lifestyles between major and non-major male students tended to be very similar. The major female students showed more health-oriented dietary behaviors in comparison with the non-major ones. Therefore, they should have a major-oriented and practically organized nutritional education program to correct their dietary behaviors and health-related lifestyles fur health.

• The Journal of Society for e-Business Studies
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• v.22 no.3
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• pp.43-55
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• 2017

The market for medical tourism services in the world is steadily increasing and the medical tourism market in the South Korea is also showing high growth. However, they have also problem such as informal various information and services, irregularity price competition etc. In order to solve this problem, We have designed a medical tourism service model based on ICT specific on domestic medical ecosystem. First, analysis trends of domestic and overseas medical ecosystem and identify current problem of medical tourism. In order to solve existed problem we also have designed a medical tourism strategy. Based on the strategy, we have designed business service model based on ICT platform for as fit as Korea medical tourism status. The proposed medical tourism business service model can provide usability to customer and also can solve current medical tourism problem. We expect industrial effect and contribution to the activation.

• Journal of the Korean Society for Railway
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• v.20 no.1
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• pp.156-163
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• 2017

In the major operation sections of the urban railway, there has been habitual delay, and delay propagation; another problem is the increase of crowds and of inconvenience to passengers. The urban railway has different characteristics from rural railways, such as uncertainty of demand and irregularity of train operation. In urban railways, recently, operators manage quality indicators of service using operation results, such as the delay of train operation and the congestion of trains. However, because the urban railway has characteristics in which demand, passenger behavior, and train operation mutually affect each other, it is difficult to express the quality of service that passengers actually feel. In this paper, we suggest a quality indicator of service from the viewpoint of passengers, and present a demand responsive multi-train simulation method to predict dynamic dwell time and train operation status; we also use simulation results to consider changes in the quality indicator of service.

• The korean journal of orthodontics
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• v.46 no.4
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• pp.199-211
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• 2016

Objective: Given the considerable disagreement between the Peer Assessment Rating (PAR) index and the American Board of Orthodontics Cast-Radiograph Evaluation, we aimed to develop a novel assessment system-the Improvement and Completion of Outcome (ICO) index-to evaluate the outcome of orthodontic treatment. Methods: Sixteen criteria from 4 major categories were established to represent the pretreatment malocclusion status, as well as the degree of improvement and level of completion of outcome during/after treatment: dental relationship (arch length discrepancy, irregularity, U1-SN, and IMPA); anteroposterior relationship (overjet, right and left molar position, ANB); vertical relationship (anterior overbite, anterior open-bite, lateral open-bite, SN-MP); and transverse relationship (dental midline discrepancy, chin point deviation, posterior cross-bite, occlusal plane cant). The score for each criterion was defined from 0 or -1 (worst) to 5 (ideal value or normal occlusion) in gradations of 1. The sum of the scores in each category indicates the area and extent of the problems. Improvement and completion percentages were estimated based on the pre- and post-treatment total scores and the maximum total score. If the completion percentage exceeded 80%, treatment outcome was considered successful. Results: Two cases, Class I malocclusion and skeletal Class III malocclusion, are presented to represent the assessment procedure using the ICO index. The difference in the level of improvement and completion of treatment outcome can be clearly explained by using 2 percentage values. Conclusions: Thus, the ICO index enables the evaluation of the quality of orthodontic treatment objectively and consecutively throughout the entire treatment process.

• Structural Engineering and Mechanics
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• v.53 no.4
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• pp.791-818
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• 2015

RC buildings constitute the prevailing type of construction in earthquake-prone region like Kathmandu Valley. Most of these building constructions were based on conventional methods. In this context, the present paper studied the seismic behaviour of existing RC buildings in Kathmandu Valley. For this, four representative building structures with different design and construction, namely a building: (a) representing the non-engineered construction (RC1 and RC2) and (b) engineered construction (RC3 and RC4) has been selected for analysis. The dynamic properties of the case study building models are analyzed and the corresponding interaction with seismic action is studied by means of non-linear analyses. The structural response measures such as capacity curve, inter-storey drift and the effect of geometric non-linearities are evaluated for the two orthogonal directions. The effect of plan and vertical irregularity on the performance of the structures was studied by comparing the results of two engineered buildings. This was achieved through non-linear dynamic analysis with a synthetic earthquake subjected to X, Y and $45^{\circ}$ loading directions. The nature of the capacity curve represents the strong impact of the P-delta effect, leading to a reduction of the global lateral stiffness and reducing the strength of the structure. The non-engineered structures experience inter-storey drift demands higher than the engineered building models. Moreover, these buildings have very low lateral resistant, lesser the stiffness and limited ductility. Finally, a seismic safety assessment is performed based on the proposed drift limits. Result indicates that most of the existing buildings in Nepal exhibit inadequate seismic performance.