• 대한임상검사과학회지
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• 제40권2호
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• pp.135-141
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• 2008

Benign paroxysmal positional vertigo (BPPV) is one of the most common clinical entities encountered in a dizziness clinic. Treatment of this disease, canalith repositioning procedures, have been reported to be successful in 44-90%. Treatment requires only one treatment visit in most patients. However, there are significant numbers of patients who require multiple treatment visits for relief. The goal of this study is to identify variables that may be associated with these difficult to treat cases. Retrospective review was performed for the patients diagnosed as BPPV at St. Carollo dizziness center. Variables for statistical analysis included age, sex, involved canal, presence of bilateral disease, presence of recent head trauma, presence of chronic otitis media, history of middle ear surgery, history of otologic surgery, unilateral vestibular loss, underlying disease such as hypertension or diabetes, change of involved canal during treatment course and number of treatment visits. Two hundred patients with BPPV who received treatment were identified from JAN. 2006 to JUN. 2007. 87% required one treatment visit, 5% required second treatment visit, and 95% were successfully treated after three treatment visits. Variables such as bilateral disease, post-traumatic BPPV, duration of symptom before treatment and change of involved canal during treatment were significantly related with number of treatments. Patient's with bilateral BPPV or with recent head trauma or longer duration of symptom are more likely to require multiple visits for canalith repositioning.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2002년도 추계학술발표회 논문집
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• pp.205-208
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• 2002

• 대한공간정보학회지
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• 제17권1호
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• pp.97-104
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• 2009

지적도근점과 도시기준점은 설치의 목적과 성격은 다르지만 측량방법, 매설 위치 등이 매우 유사하다. 그렇기 때문에 두 기준점을 연계하여 활용할 수 있다면 도근점 망실에 의한 복구비용의 최소화는 물론 배점밀도의 향상을 가져올 수 있을 것이다. 따라서 본 연구에서는 지적도근점을 기초로 도시기준점의 위치정확도를 분석하여 봄으로써 두 기준점을 연계하여 활용할 수 있는 가능성을 제시하고자 하였다. 연구결과는 다음과 같다. 연구대상지역 총 13점의 도시기준점의 위치정확도를 분석하여 본 결과, 각각의 측점에 대한 연결오차의 RMSE가 최소 ${\pm}8cm$에서 최대 ${\pm}11cm$ 오차를 보이는 것으로 나타났다. 이러한 결과는 현행 지적법에서 규정하고 있는 허용오차 범위내의 성과로 지적도근점과 도시기준점을 연계하여 이용할 수 있는 가능성을 확인할 수 있었다.

• 대한두개안면성형외과학회지
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• 제18권4호
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• pp.249-254
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• 2017

Background: Lower eyelid incisions are widely used for the orbital approach in periorbital trauma and aesthetic surgery. In general, the subciliary approach is known to cause disposition of the lower eyelid by scarring the anterior lamella in some cases. On the other hand, many surgeons believe that a transconjunctival approach usually does not result in such complications and is a reliable method. We measured positional changes in the lower eyelid in blowout fracture repair since entropion is one of the most serious complications of the transconjunctival orbital approach. Methods: To measure the positional changes in the lower eyelids, we analyzed preoperative and postoperative photographs over various time intervals. In the analysis of the photographs, marginal reflex distance 2 ($MRD_2$) and eyelash angle were used as an index of eyelid position. Statistical analyses were performed to identify the significance in the positional changes. All patients underwent orbital reconstruction through a transconjunctival incision by a single plastic surgeon. Results: In 42 blowout fracture patients, there was no statistical significant difference in the MRD2 and eyelash angle. Furthermore, there were no clinical complications, such as infection, hematoma, bleeding, or implant protrusion, during the follow-up periods. Conclusion: The advantages of the transconjunctival approach for orbital access include minimal scarring and a lower risk of eyelid displacement compared with other approaches. Based on these results, we recommend the transconjunctival approach for orbital exposure as a safe and reliable method.

• 한국수자원학회논문집
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• 제55권spc1호
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• pp.1187-1195
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• 2022

관망의 세그먼트를 파악하기 위한 알고리즘을 구동시키기 위해서는 관망의 주요 구성요소들인 절점, 파이프, 및 밸브 간의 상대적인 위치 관계를 세그먼트 탐색 알고리즘의 입력정보로 준비해야 한다. 실제 지자체 관망에 존재하는 세그먼트를 보다 정확하게 파악하기 위해서는 관망 수리해석 프로그램 구동을 위해 모델링된 관망 정보를 이용하기 보다는, 모든 제수밸브가 포함된 지자체 상수도 관망 GIS/CAD 데이터베이스를 이용하여 세그먼트 탐색에 적합하게 재구성된 관망 정보를 이용할 필요가 있다. 본 연구에서는 지자체 상수도 관망 GIS/CAD 데이터를 이용하여 관망 세그먼트 탐색에 적합한 노드-파이프-밸브 간의 상대적 위치관계를 수립할 수 있는 컴퓨터 계산 알고리즘을 개발하였으며, 이를 구현할 수 있는 MATLAB 프로그램을 개발하였다. 개발된 MATLAB 프로그램을 국내 지자체 상수도 관망에 적용하여 그 실효성을 확인하였다.

• 한국측량학회지
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• 제35권1호
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• pp.55-62
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• 2017

The SRP (Solar Radiation Pressure) model has always been an issue in the dynamic GPS (Global Positioning System) orbit determination. The widely used CODE (Center for Orbit Determination in Europe) model and its variants have nine parameters to estimate the solar radiation pressure from the Sun and to absorb the remaining forces. However, these parameters show a very high correlation with each other and, therefore, only several of them are estimated at most of the IGS (International GNSS Service) analysis centers. In this study, we attempted to numerically verify the correlation between the parameters. For this purpose, a bi-directional, multi-step numerical integrator was developed. The correlation between the SRP parameters was analyzed in terms of post-fit residuals of the orbit. The integrated orbit was fitted to the IGS final orbit as external observations. On top of the parametric analysis of the SRP parameters, we also verified the capabilities of orbit prediction at later time epochs. As a secondary criterion for orbit quality, the positional discontinuity of the daily arcs was also analyzed. The resulting post-fit RMSE (Root-Mean-Squared Error) shows a level of 4.8 mm on average and there is no significant difference between block types. Since the once-per-revolution parameters in the Y-axis are highly correlated with those in the B-axis, the periodic terms in the D- and Y-axis are constrained to zero in order to resolve the correlations. The 6-hr predicted orbit based on the previous day yields about 3 cm or less compared to the IGS final orbit for a week, and reaches up to 6 cm for 24 hours (except for one day). The mean positional discontinuity at the boundary of two 1-day arcs is on the level of 1.4 cm for all non-eclipsing satellites. The developed orbit integrator shows a high performance in statistics of RMSE and positional discontinuity, as well as the separations of the dynamic parameters. In further research, additional verification of the reference frame for the estimated orbit using SLR is necessary to confirm the consistency of the orbit frames.

• Annals of Clinical Neurophysiology
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• 제8권1호
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• pp.40-43
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• 2006

Background: Benign paroxysmal positional vertigo (BPPV) is a relatively common disorder, and is characterized by episodic vertigo and nystagmus which was provoked by head motion. However, little is known about the short and long-term outcome and the prognostic factors for recurrence of BPPV. In this pilot study, we tried to identify the prognostic factors of BPPV for short-term outcome. Methods: We analyzed clinical features of 32 patients (men=21, mean $age=60.4^{\circ}{\pm}12.6y$) with BPPV that was diagnosed by typical nystagmus induced by positioning maneuver. The induced nystagmus was recorded using video-oculography (VOG). According to the semicircular canal involved, BPPV patients were classified into horizontal, posterior, or anterior canal type. Univariate analysis for age, sex, and history of vertigo, and Kaplan-Meier analysis for each canal type were performed. Results: Horizontal (n=21, 65.6%) semicircular canal type BPPV was more common than the posterior one (n=11, 34.4%). Median follow-up period was 113 day (from 34 to 216 days). Four patients with horizontal canal type BPPV had recurrent attacks. Age, history of vertigo, and days prior to diagnosis were not different between canal type. Overall recurrence rate of horizontal canal type BPPV by Kaplan-Meier estimation was 19% at 60 days (p=0.13). Conclusions: Horizontal canal type BPPV was more common and recurred more frequently than posterior canal type in the present study. However, we did not find prognostic factors for recurrence of BPPV.

• 한방안이비인후피부과학회지
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• 제34권4호
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• pp.71-89
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• 2021

Objectives : The purpose of this study is to evaluate the effect of Banhabaeckchulchunm a-tang(BBCT) for Benign Paroxysmal Positional Vertigo(BPPV) Methods : We searched randomized controlled trials(RCTs) which assess the effect of BB CT for BPPV through 8 electronic databases from their inception to July 2021. RevMan 5.4 was used to evaluate the risk of bias. Results : 12 RCTs with 901 subjects were included. The BBCT treatment group had significantly higher total effetive rate(TER) than the western medicine treatment group(P=0.0001), and the Dizziness Handicap Inventory(DHI) score(P=0.003), traditional chinese medicine syndrome(TCM syn.) score(P<0.00001), and Visual analog scale(VAS)(P=0.0006) were significantly lower than the western medicine treatment group. The combined treatment of BBCT and canalith repositioning procedure(CRP) group had significantly higher TER than only CRP treatment group(P=0.02), and there was no significant difference in DHI score(P=0.12). TG(P=0.006) and TC(P=0.04) were significantly lower, and ApoA1 was significantly higher(P=0.0001). There was no significant difference in LDL(P=0.24). Conclusions : These results demonstrate that BBCT could be effective for BPPV especially after CRP. However, because of limits of included studies such as high heterogeneity between the literatures, unclear risk of bias, insufficient reports of adverse events(AEs), a well-designed RCTs with a low risk of bias in more diverse countries are needed in the future.

• 한국측량학회지
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• 제13권2호
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• pp.229-236
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• 1995

본 연구는 사진측정 기법을 이용하여 정밀 시공 및 주기적 안전진단을 요하는 자기부상열차 선로의 정밀 위치해석을 보다 효율적으로 처리할 수 있는 기법을 연구한 것이다. 연구결과, 사진의 해석 정확도에 절대적 영향을 미치는 평면적 기준점의 배치를 보완한 공간적 분포의 기준점을 사용하므로서, Z의 정확도뿐 아니라 X, Y의 정확도를 향상시킬 수 있었으며, 진단에 요구되는 1 mm이내의 정확도로 자기부상열차의 선로에 대한 검증을 할 수 있었다. 그리고 구조물 상면의 정밀 위치해석은 물론 종 횡단경사에 대한 기하학적 특성을 효율적으로 도출할 수 있었다.

• 한국전자현미경학회:학술대회논문집
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• 한국현미경학회 2001년도 제32차 추계학술대회
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• pp.18-22
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• 2001

A technique to characterize specific site of materials using a combination of a dedicated focused ion beam system(FIB), and Intermediate-voltage scanning transmission electron microscope(STEM) or transmission electron microscope(TEM) equipped with a scanning electron microscope(SEM) unit has been developed. The FIB system is used for preparation of electron transparent thin samples, while STEM or TEM is used for localization of a specific site to be milled in the FIB system. An FIB-STEM(TEM) compatible sample holder has been developed to facilitate thin sample preparation with high positional accuracy Positional accuracy of $0.1{\mu}m$ or better can be achieved by the technique. In addition, an FIB micro-sampling technique has been developed to extract a small sample directly from a bulk sample in a FIB system These newly developed techniques were applied for the analysis of specific failure in Si devices and also for characterization of a specific precipitate In a metal sample.