• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.12
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• pp.974-981
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• 2017

Globally, owing to the rapid expansion of radio stations overseas, the frequency coordination system is managed as a preconditioning system. As a result, it is predicted that many types of radio stations will be established for domestic purposes, such as 5G, low-power IoT devices with long distance, based on licenses and non-license in the future. Many problems such as unnecessary launching of radio resources and spectrum-sharing technology exist, and it is necessary to consider the introduction of the abovementioned system and other plan system. In this paper, we explore the outline of radio station licensing and introduce the contents of the survey on another industry licensing. The plans were studied by discussing problems that may occur in future, through comparative analysis of radio stations and other industry licensing. Moreover, the differences were compared and analyzed using graphs. Finally, we discussed the problems convergence products such as drone may offer in the future.

• Journal of Oral Medicine and Pain
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• v.20 no.1
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• pp.195-204
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• 1995

The purpose of this study was to evaluate effect of head posture change on initial occlusal contacts through measuring the distances between initial occlusal contacts and maximum intercuspal position at different head posture. Two special devices were designed and constructed. Mandibular movement replicator was used to assess reliability of the K6 diagnostic system(MKG; Myo-tronic Inc, Seatle, USA) and head posture calibrator was used to maintain the constant head posture during experiment. We measured difference of distance between initial occlusal contact and maximum intercuspal position with MKG in upright, supine, 45 degrees extension, 30 degrees flexion, 30 degrees right and left bending postion of the head. The Frankfurt horizontal plane was used as a reference plane. 21 adults aged from 23 to 25 were selected, who have normal or class I molar relationship, and have no symptoms on TMJ and masticatory muscles, and have restorations less than 3 surfaces on each tooth, and have no other prosthetic restoration. The obtained results were as follows : The mean absolute distances between initial occlusal contact and maximum intercuspal postion were 0.39(0.18mm in the upright position, 0.65(0.37mm in the supine position, 0.59(0.33mm in the 45 degree extension, 0.70(0.53mm in the 30 degrees flexion, 1.12(1.10mm in the 30 degrees right bending and 1.94(0.67mm in the 30 degrees left bending of the head. The positions of the initial occlusal contacts have a tendency to locate anterior, left and inferior to maximal intercuspal position in upright position, posterior and inferior in supine position and 45 degrees extension, anterior and inferior in 30 degrees flexion, right and inferior in 30 degrees right bending, and left and inferior in 30 degrees left bending of the head. There were significant differences among the initial occlusal contacts in each head postures(P<0.0001). Therefore, we need to check initial occlusal contacts in the altered head posture during occlusal analysis and adjustment of occlusal appliance and dental occlusion for diagnosis and treatment of temporomandibular disorder.

• Journal of The Korean Digital Architecture Interior Association
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• v.11 no.4
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• pp.5-11
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• 2011

The present study investigated the actual conditions of physical therapy rooms at long-term hospitals in Korea and conducted a comparative analysis to develop an efficient floor plan and facility improvement measures. 1. At hospitals surveyed, physical therapy services were used at a high frequency but they did not have enough space for rehab treatment and long paths of patient flow were found to make patient management inconvenient. Therefore, physical therapy units should be conveniently located both in terms of distance and direction so as to be accessible from patient rooms or wards. The space should be organized in a concentrated layout for efficiency of physical therapy, and floor planning for therapy units should ensure the best possible viewing angle to therapists. 2. With regard to the disease characteristics of patients, many physical therapy rooms were in difficult circumstances because of poor facilities, so they need to secure skilled personnel, supplement apparatuses and equipment and have rooms for functional recovery, hydrotherapy and operation treatment. In addition, each of the curtained or partitioned areas for treatment should be set up with consideration for the amount of space taken up by medical equipment. The area under each bed should be designed for patient convenience so that it can be used as storage space for patient's belongings and shoes. 3. Patients complained about the lack of physical therapy space, resting places or exercise areas and demanded the expansion of rehab programs and facilities. Physical therapy facilities need to be improved for patient privacy and effective natural ventilation. 4. At most of the long-term hospitals surveyed, physical therapy units were found to have small areas and treatment equipment and devices were insufficient compared to the number of patients. Therefore, it is required to secure more space (at least 138.24 sq. meters per 100 beds) and improve facilities for better physical therapy services.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.13-14
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• 2012

Than fluorescent lamps or light bulbs, long life, small power consumption and to the development of modern technology, LED (Light Emitting Diode) devices have the advantage of easy control. For these reasons, using the LED device, lighting has been widely used. LED using optical fiber technology using LED lighting technology with the development of wireless communication technology is attracting attention again. Using LED lights this study analyzed the performance of the technology transfer and implementation of the information transmission system of the visible light communication using LED lighting of the White Visible Light Communication (VLC) based PC module transmitter and receiver modules. Has made a system that can transmit information more than the value of the initial distance ~ 50cm, depending on the presence or absence of the lens, in order to increase the efficiency of the LED modules with different efficiencies that could confirm the performance of the implementation of the research, analysis, and application methods. and about the possibility that you want to check.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.7
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• pp.595-601
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• 2009

For the silicon oxide $(SiO_x)$ films prepared by using the facing target sputtering (FTS) apparatus that was manufactured to enhance the preciseness of the fabricated thin-film and sputtering yield rate by forming a higher-density plasma in the electrical discharge space for using it as a thin-film passivation system for flexible organic light emitting devices (FOLEDs). The deposition characteristics were investigated under various process conditions, such as array of the cathode magnets, oxygen concentration$(O_2/Ar+O_2)$ introduced during deposition, and variations of distance between two targets and working pressure. We report that the optimum conditions for our FTS apparatus for the deposition of the $SiO_x$ films are as follows: $d_{TS}\;and\;d_{TT}$ are 90mm and 120mm, respectively and the maximum deposition rate is obtained under a gas pressure of 2 mTorr with an oxygen concentration of 3.3%. Under this optimum conditions, it was found that the $SiO_x$ film was grown with a very high deposition rate of $250{\AA}$/min by rf-power of $4.4W/cm^2$, which was significantly enhanced as compared with a deposition rate (${\sim}55{\AA})$/min) of the conventional sputtering system. We also reported that the FTS system is a suitable method for the high speed and the low temperature deposition, the plasma free deposition, and the mass-production.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.6
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• pp.734-744
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• 2013

In this study, the telematics device was installed on the car (OBD-II) to collect the information on the operation conditions from each sample vehicle. Based on the information the domestic driving pattern was analysed and the ratio of cold start length was estimated. As a result of analysis for driving pattern, we found a difference in the frequency of driving on the hourly or seasonal basis. Then, the driving pattern of the rush hours, weekdays, and weekends could be derived. Also, from the study, an average of 2.22 times per day occurred in a single trip and average driving distance for the trip was 15.72 km. In addition, the proportion of cold start length was analyzed to be 16.11%. The seasonal cold start length has big difference from season to season (Winter 26.63%, Summer 8.22%, Intermediate 12.65%). There was an inverse relationship between the outside temperature and ratio of cold start length. In order to improve the accuracy of the cold emission estimation, it is necessary to apply domestic ratio of cold start length that driving pattern and temperature in Korea is reflected.

• Archives of design research
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• v.17 no.4
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• pp.61-68
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• 2004

A great variety of handheld device are coming onto the market. Some have advanced features compacted into very small sized hardware. In order to maximize the capability of these devices, we need to understand the characteristics of different input methods and utilize them in a sufficient way. Our study aims to understand characteristics of each device, so that we can design user interfaces more effectively. Two experiments were conducted to compare target pointing performance with a pen and with a hardware key on small displays. In experiment 1, we examined participants' performance of target pointing with both input methods at different target sizes. It was found that pen operation is more erroneous than key based operation when target size is smaller than 5mm, but at a target size of 5mm, the error rate decreased to the same level as for key input. In experiment 2, we examined the effect of the number of targets. The results showed, with a target size of 5mm, the pen could point to targets quicker than with key input, when the distance to the target exeeds a path length of 3 steps.

• The korean journal of orthodontics
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• v.49 no.1
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• pp.49-58
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• 2019

Objective: The aim of this retrospective study was to evaluate and compare the changes in the pharyngeal airway (PA), maxillary sinus volume, and skeletal parameters after rapid maxillary expansion (RME) and alternate rapid maxillary expansion and constriction (Alt-RAMEC) followed by facemask (FM) therapy. Methods: The records of 40 patients with skeletal Class III malocclusion due to maxillary retrognathism were collected, and the patients were assigned into two groups. The first group comprised 8 male and 12 female patients (mean age, $10.0{\pm}1.1years$) treated using RME/FM for an average of 10 months. The second group comprised 10 male and 10 female patients (mean age, $9.64{\pm}1.3years$) treated using Alt-RAMEC/FM for an average of 12 months. Cone-beam computed tomography images acquired before (T0) and after treatment (T1) were evaluated. Results: Regarding the skeletal effects, significant differences between the groups were the increase in ANS-HRP (perpendicular distance of ANS to the horizontal reference plane, 0.99 mm, p <0.05) in the Alt-RAMEC/FM group and the decrease in PP-SN (palatal plane to Sella-Nasion plane, $0.93^{\circ}$, p < 0.05) in the RME/FM group. Maxillary sinus volumes increased significantly in both the groups, and the increase was statistically significantly higher in the Alt-RAMEC/FM group. Although no significant intergroup differences were observed in PA volumes, both lower ($1,011.19mm^3$) and total ($1,601.21mm^3$), PA volume increased significantly in the Alt-RAMEC/FM group. Conclusions: The different expansion devices and protocols used with FM therapy do not seem to affect the forward movement of the maxilla and PA volumes. In contrast, the increase in maxillary sinus volume was greater in the Alt-RAMEC/FM protocol.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.12A
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• pp.982-990
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• 2009

The IEEE 802.15.4 wireless sensor network is composed of the unique sensor devices to monitor and collect physical or environmental conditions. The interests in a positioning technology, which is one of the environment monitoring technologies, are gradually increased according to the development of the sensor technology and IT infrastructure. Generally, it is difficult for the positioning system using RSSI (Received Signal Strength Indication) based implementation to get accurate position because of obstacles, RF wave's delay and multipath. Therefore, in this paper, we investigate the improved positioning technologies for RSSI-based positioning system. This paper also proposes the enhanced scheme to improve the accuracy of positioning system by applying the Gaussian Filter algorithm, which is widely used for enhancing the performance of image processing system. For the implementation of proposed scheme, we firstly make a look-up tables, which represent the distance between target node and master node and corresponding RSSI value of each target node which are recorded as an average value after investigating the characteristics of attenuation of transmitted signal By applying the pre-determined look-up tables and Gaussian Filtering in the proposed scheme, we analyzed the positioning performance and compared with other conventional RSSI-based positioning algorithms.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.9
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• pp.757-762
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• 2012

In general, an ordinary CCTV camera has equipped with 24 frames per second. This camera is not capable of capturing an image of bullet trace which has speed about 1km per second. In spite of these difficulties, by means of the stereographical projection, a long distance trace is able to be contained in one image. Currently, to capture a series of image of an object with high speed, it is usual to use one of the complicated camera with high shutter speed or computerized devices with capability of controlling shutter timing with slightly different capture time. This paper proposed a monitoring tracer bullet single camera system equipped convex mirror trying to see whether or not a normal set of camera and convex mirror is capable of shooting on target located in as far as 250m.