• Journal of Korean Dental Science
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• v.16 no.2
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• pp.115-127
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• 2023

The demand for orthodontic clear aligner therapy (CAT) has increased significantly over the last decade, offering advantages over the fixed appliances (FA) including enhanced aesthetics, better hygiene and comfort, along with minimal restrictions on the patient's diet. Moreover, a marked improvement in the efficacy of tooth movement using aligners has been documented. On the contrary, there have been known limitations of CAT including the compliances issues and the apparent lack of efficacy for certain types of tooth movement such as closure of extraction space compared to FA. Thus, evidence-based evaluation of the accuracy of prediction of tooth movement with clear aligners and their ability to effectively perform major tooth and root movements compared to FA are crucial. Although several systematic reviews have investigated various aspects of the effectiveness of CAT, we are yet to obtain a rather conclusive answer to this question. The current review attempted to summarize the evidence-based findings of most systematic reviews about CAT available to date. Major issues regarding the predictability of tooth movement, the role of attachments and auxiliaries in improving the effectiveness of CAT, and the treatment outcomes in comparison to FA were investigated. Clinical recommendation have been also elaborated based on the interpretation of the findings of all systematic reviews included in this study.

• Industry Promotion Research
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• v.5 no.3
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• pp.105-122
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• 2020

The purpose of this thesis is to contemplate Astrology, 28 Fixed star, and Naksatra. The goal of this study was to look through the birth process of Astrology in the classical literature, and to examine how it can be applied to each individual's life by looking into the meaning of 28 Fixed star and Nakshatra. From the literary review, Astrology existed among the Babylonians 1000 BC and it originated from the start of calling by naming the animal. Assyrians called it "the zodiac is the Way of the Moon" which was written on Molapin in the Enuma Anu Enil, the clay plate recorded by Assyrians. Therefore, it was found that the zodiac, called Astrology, was made through the movement of the moon. There are also 28 stars in 배도, which is the way the moon passes, and it is called 28 Fixed star. 28 Fixed Star is called Nakshatra in India and can read the natural destiny of an individual through Nakshatra., Knowing the lunar month and date, you can find the individual Nakshatra and choose the best life in the framework of your natural destiny. Therefore, this researcher reviewed the literature on Astrology, 28 Fixed Star and Nakshatra and suggested the utilization plan. I hope this study will help the related field in the future.

• The Korean Journal of Nuclear Medicine Technology
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• v.23 no.1
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• pp.54-58
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• 2019

Purpose At now, there are many kind of dedicated heart SPECT machine in clinical nuclear medicine. Among those, the fixed focusing type SPECT can make a good quality, quantity image because a detectors of this SPECT arranged forward a special ROI and didn't rotate around of body. So, in this paper, we will evaluate a spatial uniformity about resolution and sensitivity at a same plane of a fixed focusing type SPECT. Materials and Methods We used D-SPECT as a fixed focusing type SPECT and Cario MD as a rotated parallel type SPECT to comparing each other. We injected $^{99m}Tc(14.8MBq/1cc)$ to 10 capillary tube (diameter=1mm), and we set those line sources a tfield of view of each SPECT. And then we acquired SPECT date, we applied are construction by recommended methods. By using two tomography images, we calculated a full width of half maximum as a resolution and total counts as a sensitivity, and we compared a CV (coefficientofvariation) values between two images as a spatial uniformity. Results In case of D-SPECT, a CV of resolution and sensitivity are 7.45%, 12.34%. In case of Cario MD, an CV of resolution and sensitivity are 12.49%, 21.84% Conclusion As a results, CV of resolution and sensitivity of a fixed focusing type SPECT is 67.75%, 77.00% higher than ones of a rotated parallel type SPECT. It means that a fixed focusing type SPECT is more uniformed, because this new SPECT can reduce a motion blur artifact by rotating detector around body, also all of detector that made by semiconductor arrange forward a special FOV like heart.

• Journal of Industrial Technology
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• v.28 no.A
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• pp.43-49
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• 2008

The track of high-speed railway get deteriorated according as using it. In that case, the maintenance jobs are needed for improvement of track quality. A scheduling problem for the track maintenance of high-speed railway is to determine the jobs should be performed daily. In the problem, the set of jobs for maintenance is given. Each job has it's parameters such as due date, emergency level, and processing time. In addition, jobs can be worked during a certain fixed time when the train doesn't move. In this study, we developed a mathematical model of the scheduling problem for the maintenance of high-speed railway and solved the problem using the ILOG CPLEX library.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.5
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• pp.43-50
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• 2002

Friction welding has many merits such as energy efficiency, simple processing, etc butt difficult to obtain good weld at the welded interface and heat affected zone. To date, the continuum mechanics and fracture mechanics are utilized to analyse stresses at the interface and propagation of cracks. In this study. STS304 and SM15C are selected because they can be differentiated distinctively from metallic point of view and crack can be observed easily. It is ovserved during friction welding that STS304, rotary part is hatter than SH15C, fixed part. The last fracture occurs around the center because the surface of fatigue fracture has smooth regions, due to the separation phenomenon in plastic flows layers and striation dimple pattern.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.933-938
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• 2007

These days, up-to-date humanoid robots are continuously developed. Among them, Qrio, Asimo[1,2] are famous for its unique walking technology and natural movement. These robots could show manufacturers' technological improvement and leave a good impression to the customer. In accordance with global trends, Samsung is also producing humanoid robot. The humanoid robot, however, could walk like a human compared to the industrial robot fixed in the factory. This feature could cause another dynamic effect while walking. In this paper, the robot's feet were examined to find out parameters that affect stability of the humanoid robot's feet. With the sensitivity analysis, the optimization procedure in design of experiments finds the most suitable performance of robot. Maximum deflection of the frame upon various cases was minimized, and rubber coefficients for shock absorption were optimized.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.454-460
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• 2009

The objective of this study is to study the selection factors and satisfaction factors for different types of driving ranges and establish a basic date for marketing strategies of driving ranges. The research target group was fixed to customers older than full twenty of 12 indoor, outdoor driving ranges located in G metropolitan city & N city, M city, S city in. 564 surveys were used as effective samples. The result was achieved using the above mentioned objectives and methods.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.10 no.S_1
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• pp.11-22
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• 2001

Observations related to the along-wind dispersion of puffs were collected from 12 field sites and from a wind tunnel experiment and used to test simple similarity relations. Because most of the date made use of concentration time series observation from fixed monitors, the basic observation was t, the standard deviation of the concentration time series. This data also allowed the travel time, t, from the source to the receptor to be estimated, from which the puff advective speed ue, could be determined. The along-wind dispersion coefficient, x, was then assumed to equal tue. The data, which extended over four orders of magnitude, supported the similarity relations t=0.1 t and x=1.8 $u^*$t, where t is the travel time and $u^*$ is the friction velocity. About 50% of the observations were within a factor of two of the predictions based on the similarity relations.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.7 no.1
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• pp.1-9
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• 1989

Up to date, the ditermination of three dimentional position is performed sperately by horizontal and vertical adjustment. The purpose of this study is to determine simultaneously three dimentional coordinates of one unknown point by measuring only three slope distances from one unknown point to three fixed points. In this study, the adjustment problem for measurement values inclading redundancy is solved by observation equation and condition equation, and also the characteristic of these two analysis methods is studied and investigated.

• Korean Journal of Breeding Science
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• v.43 no.2
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• pp.145-153
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• 2011

To develop new varieties of rapeseed (Brassica napus L.), the seeds of three varieties 'Naehan', 'Tammi', and 'Halla' were treated with proton ion beams and gamma rays (0~2,000 Gy), and then the characteristics of the mutants induced were examined up to $M_5$ generation to select the lines with fixed useful traits. In $M_5$ generation, we had selected several lines that were highly fixed for some useful traits such as plant height, maturity and flower size; one line with both earlier maturity and shorter stem than wild type, one line with only earlier maturity, two lines with shorter stem, one line with large flower, and one line with chlorophyll mutation. Among them, NP600-1-1-198-2 (induced from variety 'Naehan' was treated with proton ion beams 600 Gy) was superior for its distinction from the original variety, uniformity and stability. The unique characteristics of NP600-1-1-198-2 were dark green leaves, green stem, yellow flower, and black seed coat. Its flowering date was April 14, eight days earlier than its original variety, while seed maturity date was June 16 (five days earlier) and plant height 105 cm (shorter by 10 cm). NP600-1-1-198-2 has 52 silique per panicle, 6.2 cm silique length, 23 seeds per silique, 4.2 g per 1000 seeds and 45.9% oil content. The seed oil contained 67.8% of oleic acid, 16.7% of linoleic acid and 7.3% of linolenic acid but no erucic acid.