• Restorative Dentistry and Endodontics
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• v.28 no.2
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• pp.146-155
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• 2003

여러 가지 장점으로 인해 Ni-Ti 전동 파일을 근관성형에 사용하는 빈도가 점차 증가되는 추세이지만, 초심자를 대상으로 한 연구는 부족한 실정이다. 이에 본 연구에서는 초심자에서 Ni-Ti 전동 파일을 사용할 때 근관 형성의 효용성을 평가하고, 어떤 방법이 초심자에게 적절한지를 알아보고자 하였다. 근관형태가 재현된 레진 블록을 이용하여 12명의 초심자와 4명의 숙련자가 근관 형성을 시행하였다. 각 술자는 ProFile, ProTaper, Hybrid (ProFile＋ProTaper)를 이용하여 각각의 레진 블록을 세 개씩 근관형성하고, 각 파일 별의 근관 형성 시간을 기록하였다. 근관 형성 전과 후의 digital 이미지를 중첩하여 치근단으로부터 1, 2, 3, 4, 5, 6, 7mm level에서 근관단면의 총길이 변화량, 만곡 외측의 길이 변화량, 만곡 내측의 길이 변화량, 중심이동량, 중심이동율과 치근단에서의 apical transportation을 구하고, 초심자와 숙련자 사이의 차이를 비교 평가하였다. 실험결과 ProFile군의 1, 3, 5, 6, 7mm level과 ProTaper군의 6mm level, Hybrid군의 3mm level에서 초심자의 근관단면의 총길이 변화량이 숙련자보다 많았다. 모든 군에서 치근단으로부터 4, 5, 6, 7mm level에서는 근관 중심이 만곡내측으로 이동하였고, 1 2, 3mm level 에서는 만곡외측으로 이동하였으나, 숙련자가 시행한 Hybrid군의 3mm level과 비숙련자가 시행한 ProTaper 군의 3mm level에서는 만곡내측으로 이동하였다. 모든 군의 3mm level과 ProFile 군의 5mm level에서 초심자의 중심이동율이 숙련자에 비해 컸으며, 초심자가 ProTaper를 사용시 더 큰 apical trans portation을 보였고, 모든 군에서 초심자가 근관형성시 더 많은 시간이 걸렸다. ProFile과 ProTaper를 이용한 Hybrid technique이 초심자에게 추천되며, 초심자들도 충분히 교육받는다면 만곡된 근관의 근관형성에 있어서 Ni-Ti rotary file의 이용이 가능하리라고 사료된다.

• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.5
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• pp.616-621
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• 2006

Recently many cars are equipping a navigation system. The main purpose of the early system guides a user through the route. A navigation system includes various abilities by development of various technologies and it has given more convenience to user. It can play various records on the tape and announces which are useful information about each road. Also it can use various multi-media contents by DMB device during driving. However, guide function of basic and important road in the navigation system has not grown greatly yet. In this paper, we proposed recommendation method of human-friendly road considering user's condition through various information of outside environment, user's velocity intention, a driver's emotion and a preference of the road. Modules consists of hierarchical structure that can easily correct and add each algorithm and those use fuzzy logic algorithm.

• Asian Journal of Turfgrass Science
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• v.22 no.2
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• pp.217-223
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• 2008

This study was conducted to figure out the effect of silicate as growth stimulator on growth of 'Pencrosss' creeping bentgrass. Creeping bentgrass(Agrostis palustris cv. 'Pencross') at the nursery of Sinwon Country Club was used. Silicate was applied at the concentration of 0, $200{\times}$, $500{\times}$, $1.000{\times}$. Polt size was 1 by 2 meter and there were three replications with completely randomized design(CRD). Creeping bentgrass growth was evaluated with visual turf grass quality, root length and No. of tiller density(ea/$cm^2$). Results of this study are as followings; 1. Average root length with silicate was $1.5{\sim}1.9cm$ longer than control. Especially, Root length of silicate was $7{\sim}8cm$ in summer. 2. Tiller density with silicate was $l8{\sim}22ea/cm^2$, $0.4{\sim}2.l$ less than control. But there was no significant difference. 3. Visual turfgrass quality with silicate was $5.0{\sim}8.3$, $0.3{\sim}1.5$ higher than control. But there was no significant difference. In conclusion, silicate might be grown as root growth stimulator of creeping bentgrass during summer in Korea. However, this study was conducted under one year. Accordingly, in-depth experiment should be done over several years.

• Korean Journal of Medicinal Crop Science
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• v.14 no.4
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• pp.206-211
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• 2006

This study was performed to examine antitumor activities of Rubus coreanus Miquel and Angelica gigas Nakai extracts against sarcoma-180 and anti-stress activities in ICR mice. The variation of body weights of the 20 days of Rubus coreanus extracts-administrated mice group was very low. The survival rate (T/C %) of Rubus coreanus extract administrated group was 161% after 50 days from the inoculation of sarcoma-180 and the increment of their body weights was suppressed. Anti-stress effect of the extracts of R. coreanus and A. gigas were estimated by maeasuring blood chemical value and internal organs weight in ICR mice. The extracts of R. coreanus reduced the cholesterol and glucose to the normal level in the all stress animal models. The extracts of R. coreanus reduced the hypertrophy of the internal organs such as adrenal, spleen and liver to the regular level.

• Journal of KIISE:Databases
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• v.37 no.6
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• pp.343-350
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• 2010

We can get answers we want to know via questioning in Knowledge Search Service (KSS) based on Q&A Community. However, it is getting more difficult to find credible documents in enormous documents, since many anonymous users regardless of credibility are participate in answering on the question. In previous works in KSS, researchers evaluated the quality of documents based on textual information, e.g. recommendation count, click count and non-textual information, e.g. answer length, attached data, conjunction count. Then, the evaluation results are used for enhancing search performance. However, the non-textual information has a problem that it is difficult to get enough information by users in the early stage of Q&A. The textual information also has a limitation for evaluating quality because of judgement by partial factors such as answer length, conjunction counts. In this paper, we propose the QualityRank algorithm to improve the problem by textual and non-textual information. This algorithm ranks the relevant and credible answers by considering textual/non-textual information and user centrality based on Social Network Analysis(SNA). Based on experimental validation we can confirm that the results by our algorithm is improved than those of textual/non-textual in terms of ranking performance.

• Journal of Korean Society of Forest Science
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• v.111 no.1
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• pp.186-200
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• 2022

The purpose of this study was to provide the basic data necessary for stakeholders to establish and promote policies related to the national forest trail. Awareness analysis was conducted on 800 visitors to the national forest trail, specifically to the Jirisan trail and Daegwallyeong forest trail, as well as 1,200 members of the public. Awareness of the national forest trail was low and at a similar level for both visitors and the general public; however, compared with the general public, the visitors had a higher need for the national forest trail system and were willing to visit and recommend the trail. The most common answers in response to the purpose of visit, reason for choosing the national trail, matters of interest, problems, necessary regulation, and role expectations were similar among the visitors and general public. Based on gender and age, there was a significant difference in the matters of interest and desired activity, but "scenery" was the most crucial factor. Therefore, after a comprehensive survey on the major view points, given that "scenery" was identified as an attractor, a system should be developed to identify and provide the information desired by visitors and the general public. These results are expected to be employed as basic data for stakeholders in decision making related to the national forest trail.

• Journal of the Korea Institute of Building Construction
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• v.18 no.2
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• pp.99-107
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• 2018

The objective of the present study is to propose a reliable shape of supplementary V-ties in the section jacketing approach for seismic strengthening of reinforced concrete columns. A total of 24 pull-out specimens were prepared. The test parameters selected with regard to bond strength of V-ties were the shape of V-ties, embedment length of V-tie legs, and compressive strength of concrete. The measured bond strength of V-ties with different shapes were compared with that of the conventional V-ties and predictions using CEB-FIP equation. Ultimately, V-ties with pressed end-details at their legs could be recommended for the supplementary lateral reinforcement of strengthening columns with jacketing thickness less than the embedment length [= max (75mm, $6d_b$)] of conventional V-ties, where $d_b$ is the diameter of the reinforcing bar used for V-ties.

• Archives of design research
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• v.12 no.1
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• pp.157-166
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• 1999

With the increase in use of the computer, the VCT syndrome has occured as a new socialJhea/health problem. ErgonomicaI design standards are a for the users to reduce stress and poor physical posture in the human body. In this study. we have suggested design dimensions recommended from previous studies. We also have reviewed users' preference dimenision, and analyzed differences between users' preference dimenision. and the previous design aiteria to verify physical appropriateness. We analyzed how each design dimension was reached and affected the tunan body by objective EMG evaluation. and subjective evaluation of physical discomfort and oorrIort. We have found that keyboard height is very important in a workstation. If the elbow's height is lower than the keyboard's height. it effedS the hand and wrist. If higher, it brings fatigue to the shoulder and neck. As a result of this experiment. we suggested that the height of a keyboard desk for Koreans be 660mm for the fixed type and 540-774mm for the adjustable type. Also other design reoommendations were suggested in the thesis. In ooncIusion, our research will be very important in the database because it provides adjustable ranges to fit user's body types in the various design flekIs.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.4
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• pp.67-75
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• 2012

For the last few years, LBS has attracted considerable attention from many industries and societies as a result of propagated smart devices. LBS has a high utilization of mobile users as it uses user positions as a significant factor. Current LBS has only taken user position into account and it makes some limits. So, it is necessarily suggested that support for personalized services which consider user's motion, traffic condition, weather condition, time, personal information and preferences that have a huge impact on the accuracy. The purpose of this study is to design the inference systems with user's motion, preferences and schedules and provide users with the personalized information. To achieve this, Movement Ontology, User Profile Ontology, Schedule Ontology and Work Ontology should be constructed and based on this, smart applications were developed. Developed applications induced appropriately recommended results according to user's preference, motion and directions.

• Clean Technology
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• v.17 no.4
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• pp.363-369
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• 2011

To evaluate the feasibility of electrodialysis for ammonia nitrogen removal from wastewater, the effects of operating parameters such as diluate concentration, applied voltage and flow rate on the removal of ammonia nitrogen were experimentally estimated. The removal rate was evaluated by measuring the elapsed time for ammonia nitrogen concentration of diluate to reach 20 mg/L. Limiting current density (LCD) linearly increased with ammonia nitrogen concentration and flow rate. The elapsed time was linearly proportional to initial concentration of diluate. Due to relatively large equivalent ion conductivity and ion mobility of ammonia nitrogen, the removal rate increased consistently with flow rate. Increase in the applied voltage gave positive effect to removal rate. From the operation of the electrodialysis module used in this research, the flow rate of 3.2 L/min and 80~90% of applied voltage for LCD are recommended as the optimum operating condition for the removal from high concentrate ammonia nitrogen solution.