• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.04a
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• pp.133-142
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• 1992

A kineamatic nonlinear multivariable laundher is modeled of which the azimoth and elevation axes are drived simultaneously and SISO and MIMO LQG/LTR controllers are designed and evaluated for this system. Also, the suitable command input function is suggested for the desired command following performance and the LQG/LTR control system with disturbances and load variation is evaluated for the entire operating range by computer simulation. It is found that the linear SISO LQG/LTR controller can be used for the kinematic nonlinear multivariable launder in the entire operating range and is effective for disturbance rejection and load variation.

• Journal of Periodontal and Implant Science
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• v.36 no.2
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• pp.345-359
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• 2006

Loss of maxillary molar teeth leads to rapid loss of crestal bone and inferior expansion of the maxillary sinus floor (secondary pneumatization). Rehabilitation of the site with osseointegrated dental implants often represents a clinical challenge because of the insufficient bone volume resulted from this phenomenon. Boyne & James proposed the classic procedure for maxillary sinus floor elevation entails preparation of a trap door including the Schneiderian membrane in the lateral sinus wall. Summers proposed another non-invasive method using a set of osteotome and the osteotome sinus floor elevation (OSFE) was proposed for implant sites with at least 5-6mm of bone between the alveolar crest and the maxillary sinus floor. The change of grafted material in maxillary sinus is important for implant survival and the evaluation of graft height after maxillary sinus floor elevation is composed of histologic evaluation and radiomorphometric evaluation. The aim of the present study was radiographically evaluate the graft height change after maxillary sinus floor elevation and the influence of the graft material type in height change and the bone remodeling of grafts in sinus. A total of 59 patients (28 in lateral approach and 31 in crestal approach) who underwent maxillary sinus floor elevation composed of lateral approach and crestal approach were radiographically followed for up to about 48 months. Change in sinusgraft height were calculated with respect to implant length (IL) and grafted sinus height(BL). It was evaluated the change of the graft height according to time, the influence of the approach technique (staged approach and simultaneous approach) in lateral approach to change of the graft height, and the influence of the type of graft materials to change of the graft height. Patients were divided into three class based on the height of the grafted sinus floor relative to the implant apex and evaluated the proportion change of that class (Class I, in which the grafted sinus floor was above the implant apex; Class II, in which the implant apex was level with the grafted sinus floor; and Class III, in which the grafted sinus floor was below the implant apex). And it was evaluated th bone remodeling in sinus during 12 months using SGRl(by $Br\ddot{a}gger$ et al). The result was like that; Sinus graft height decreased significantly in both lateral approach and crestal approach in first 12 months (p$MBCP^{TM}$ had minimum height loss. Class III and Class II was increased by time in both lateral and crestal approach and Class I was decreased by time. SGRI was increased statistically significantly from baseline to 3 months and 3 months(p<0.05) to 12 months(p$ICB^{(R)}$ single use, more reduction of sinusgraft height was appeared. Therefore we speculated that the mixture of graft materials is preferable as a reduction of graft materials. Increasing of the SGRI as time goes by explains the stability of implant, but additional histologic or computed tomographic study will be needed for accurate conclusion. From the radiographic evaluation, we come to know that placement of dental implant with sinus floor elevation is an effective procedure in atrophic maxillary reconstruction.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.1
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• pp.43-48
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• 2020

Open pit mines for limestone mining require rapid development of technologies and efforts to prevent safety accidents due to rapid deterioration of the slope due to deforestation and rapid changes in the topography. Accurate three-dimensional spatial information on the terrain should be the basis for reducing environmental degradation and safe development of open pit mines. Therefore, this study constructed spatial information about open pit mine using UAV(Unmanned Aerial Vehicle) and analyzed its utility. images and 3D laser scan data were acquired using UAV, and digital surface model, digital elevation model and ortho image were generated through data processing. DSM(Digital Surface Model) and ortho image were constructed using image obtained from UAV. Trees were removed using 3D laser scan data and numerical elevation models were produced. As a result of the accuracy analysis compared with the check points, the accuracy of the digital surface model and the digital elevation model was about 11cm and 8cm, respectively. The use of three-dimensional geospatial information in the mineral resource development field will greatly contribute to effective mine management and prevention of safety accidents.

• Journal of The Korea Institute of Healthcare Architecture
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• v.27 no.3
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• pp.71-78
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• 2021

Purpose: It is important to plan the ward module at a time when the size of beds, the floor area, and the construction budget are all set prior to the hospital design. In this context this study aims (1) to derive various factors affecting the ward module, and (2) to analyze the appropriate room module according to the type. Methods: Design factors related to hospital modules are derived through precedential studies, and the types of ward elevation are classified by reviewing the drawings of 18 case hospitals. And the detailed dimensions and area of the derived elements are analyzed. Results: The X-axis modules of the ward are switched to long span structural columns of 9.9 m, 12.6 m and 13.2 m, but the ward modules still represent 6.6 m. The Y-axis module of the ward shows a dimension of 9 to 9.9m in the process of changing a multi-person room into a four-person room. Type A of curtain wall with columns located on the wall of the room and type B of curtain wall located in the center of the room are analyzed due to their variations. The square window type, which forms the elevation of the square window by exposing the columns to the elevation, and the outframe type, which protrudes from the structural columns and beams, have elevation designs limited. There are, however, no obstacles to the interior space of the hospital room, so the wall composition and furniture arrangement are expected to be free. The ward area of Curtain Wall Type A, which can secure an effective area of 5.9m*5.0m, are 52.1m². The Curtain Wall Type A, Square window type, and the outframe type are 49.8m². Implications: As part of the hospital standard module plan for economical and reasonable hospital building planning, a type was proposed in this study in conjunction with the external design. It is hoped that it be a base for standard module research linked together to the Central Treatment department, Outpatient department and underground parking lot.

• Journal of Advanced Navigation Technology
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• v.22 no.6
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• pp.610-615
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• 2018

Globally, global navigation satellite system (GNSS) is being developed and operated in advanced countries. China's Beidou is developing rapidly, starting with global positioning system (GPS), which is the most representative system. In this paper, we analyze the visibility of Beidou satellite in Korea at present time to utilize rapidly changing Beidou. In this analysis, it is compared with GPS which is stable service. The results of the visibility analysis are based on the results of the mask angle (the low elevation satellite exclusion angle) and the result of the skyplot (a visual representation of the position of the satellite at the user location). Visibility analysis shows that the high elevation angle of Beidou satellite is higher than that of GPS satellite in Korea. In addition, GPS and Beidou's availability and positioning accuracy analysis are performed to confirm the effect of increasing elevation angle satellites. According to the results, Beidou is more effective than GPS in using high elevation satellites in Korea.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.4
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• pp.238-246
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• 2015

A stepping motor is widely used to operate the elevation and azimuth stage of the X-band antenna with 2-axis gimbal system for effective image data transmission from a satellite to a ground station. However, such stepping motor also generates an undesirable micro-vibration which is one of the main disturbance sources affecting image quality of the high-resolution observation satellite. In order to improve the image quality, the micro-vibration isolation of the X-band antenna system is essential. In this study, the low rotational stiffness isolator has been proposed to reduce the micro-vibration disturbance induced by elevation direction operation of the X-band antenna. In addition, its structural safety was confirmed by the structure analysis based on the derived torque budget. The effectiveness of the design was also verified through the micro-vibration measurement test.

• Journal of Korean Clinical Nursing Research
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• v.22 no.3
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• pp.249-256
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• 2016

Purpose: The purpose of this study was to examine the effect of leg raising and peripheral excercise on recovery of the patients who were applied with dexmedetomidine for their dental surgery. Methods: There were two groups, the experimental group (n=35) and control group (n=35), in this study. We checked blood pressure, pulse rate, oxygen saturation, sedation level and symptoms such as dizziness and somnolence every 30 minutes. These parameters were assessed throughout the participants' recovery room stay. Leg raising and peripheral excercise were conducted in the experimental group in the recovery room. We have conducted chi-square test, Fisher's exact test, t-test, ANOVA, and ANCOVA to compare the measured parameters in both groups. Results: The experimental group showed a significant elevation of mean arterial blood pressure, and mitigation of somnolence, sedation and dizziness compared to the control group. Conclusion: Leg raising and peripheral exercise is effective to expedite recovery in the patients who were applied with dexmedetomidine for their dental surgery.

• Journal of Nutrition and Health
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• v.32 no.6
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• pp.661-670
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• 1999

Effects of Ca supplementation on blood pressure(BP) response to dietary Na level were studied in 15 normotensive healthy college women with family history of hypertension. All subjects, randomly divided into 3 groups, ate low Na diet(1816mg/day) prepared in the laboratory during the first 2 weeks and normal Na diet(4064mg/day) of their own home for the next 8 weeks. The one group received daily 1g Ca supplement at both low and normal Na diet periods, the second group took daily 1g Ca supplement only at normal a diet period, and the last group took placebo during both periods. Average Ca and energy intakes at the basal of and during the trial ranged 450-600mg and 1735-1878kcal, respectively. Systolic/diastolic BP was decreased by 9.2-9.8/4.4-4.5 mmHg during low Na diet period and was increased again during next normal Na diet period. However simultaneous Ca supplementation during both low and normal Na diet period suppressed the elevation of systolic/diastolic BP occurred at normal Na diet period. Ca supplementation only at normal Na diet peroid did not affect the BP elevation. The increase of serum Ca and Ca/Mg ratio and the decrease of serum Na and Na/K ratio might be related to the BP lowering effects of Ca supplementation. In conclusion, Ca supplement could attenuate BP elevation induced by increasing Na intake. The BP lowering effect of Ca supplementation was not appeared at low Na intake. Further studies were needed to make it certain. Low Na intake was also confirmed as an effective diet control for lowering blood pressure.

• Archives of Plastic Surgery
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• v.42 no.5
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• pp.588-595
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• 2015

Background Radiotherapy treatment after keloidectomy is known to be an effective method for reducing the rate of recurrence. However, to date, the appropriate total radiation dose and fractionation have not yet been confirmed. The authors performed a retrospective analysis to identify the appropriate radiation dose and fractionation in post-keloidectomy radiotherapy. Methods From May 2000 to February 2011, postoperative radiotherapy was performed on 39 lesions in 28 patients after total keloidectomy. The keloid lesions were confined to the ear lobes. Between May 2000 and May 2004, 14 keloids were treated with surgical excision, followed by a total radiation dose of 1,200 cGy in three fractions over four to five days (group 1). Between June 2004 to February 2011, 25 keloids were treated with surgical excision, followed by a total radiation dose of 1,500 cGy in three fractions over four to five days (group 2). Patients were given a survey asking them to report their experiences regarding reoperation, recurrence of symptoms, recurrence of the lesion, and satisfaction with the operation. Results Of the 28 patients who were treated, 20 underwent follow-up. Group 2 had more cases showing elevation with erythematous changes, whereas group 1 had more cases showing progressive stages of elevation than group 2. These differences were statistically significant. Moreover, a correlation was observed between the level of keloid elevation and the extent of symptoms. Conclusions We suggest 1,500 cGy of radiation in three fractions following keloidectomy for ear lobe keloids. A further randomized study is needed to assess the recurrence of keloids after radiotherapy.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.1
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• pp.28-39
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• 2007

The purpose of this study is to evaluate the regenerative capacity of reconstruction in the atrophied posterior maxilla by comparing bone graft procedures and alveolar distraction osteogenesis (ADO) techniques. We performed the autogenous iliac bone graft (AGB group, 5 specimens in 3 patients), and the combination (Mixed group, 3 specimens in 3 patients) of the autogenous and deproteinized bovine bone ($Bio-Oss^{(R)}$, Geistlich Co., Switzerland) as the ratio of 2:1 in the sinus floor elevation procedures. ADO procedures using $TRACK^{(R)}$ (KLS Martin Co., Germany) were also performed to augment vertical alveolar height in atrophied posterior maxilla (ADO group, 5 specimens in 4 patients). Newly generated bone tissues were obtained with the 2.0mm diameter trephine bur (3i Co., USA) during implant fixture installation after 5-7 months. Routine histolomorphological observation, immunodot blot assay for quantitative evaluation, and immunohistochemical staining with antibodies to MMP-1, -9, -10, TIMP-1, -2, and BMP-2, -4 were all carried out. Lamellar bone formation was well shown in all specimens and new bone formations of ADO group increased than those of other procedures. In immunohistochemical staining, the strong expression of BMP-2 was shown in all specimens, and immunodot blot assay showed that bone formation is accompanied by the good induction of factors associated with angiogenesis and appeared more increased amount of osteogenic and angiogenic factors in ADO group. ADO is the most effective technique for new bone formation compared to sinus floor elevation with autogenous or mixed bone graft in the atrophied posterior maxilla. In the quantitative immunodot blot assay, the regenerated bone after ADO showed more increased products of VEGF, BMP-2, PCNA and MMP-1 than those after the other procedures, and these findings were able to be confirmed by immunohistochemical stainings.