• Title/Summary/Keyword: positional analysis

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Treatment of Benign Paroxysmal Positional Vertigo (양성돌발성 체위현훈의 치료)

  • Kim, Chul-Seung
    • Korean Journal of Clinical Laboratory Science
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    • v.40 no.2
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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.

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An Analysis on Positional Accuracy of Urban Control Point for Connecting to Supplementary Control Point (지적도근점과 연계활용을 위한 도시기준점의 위치정확도 분석)

  • Hong, Sung-Eon
    • Journal of Korean Society for Geospatial Information Science
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    • v.17 no.1
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    • pp.97-104
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    • 2009
  • Supplementary control point and urban control point have different purpose and characteristic in the view of installation but their measurement method and permanent marker position are very similar. Therefore if we could use them by connecting those two control point, we would improve the arrangement density as well as minimizing cost of restoration from the loss of control point. So we tried to suggest the possibility of connecting these two control point and usage by analysing positional accuracy of urban control point on the base of supplementary control point in this study. The result of this study is as following. When analysing the positional accuracy of 13 urban control points of the study areas, there were RMSE of connection errors between ${\pm}8cm$ and ${\pm}11cm$ for each measurement point. The result confirmed the possibility of connecting supplementary control point to urban control point and its usage within the allowable error tolerance that the present cadastral law permits.

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The Reliability of the Transconjunctival Approach for Orbital Exposure: Measurement of Positional Changes in the Lower Eyelid

  • Yoon, Sung Ho;Lee, Jin Hoon
    • Archives of Craniofacial Surgery
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    • v.18 no.4
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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.

Development of the algorithms for establishing the relative positional relations between node-pipe-valve of water pipe networks (상수도 관망의 노드-파이프-밸브 사이의 상대적 위치 관계를 수립하기 위한 알고리즘의 개발)

  • Park, Suwan;Jeon, Ye Jun;Kim, Kyeong Cheol;Lee, Hyun Dong
    • Journal of Korea Water Resources Association
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    • v.55 no.spc1
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    • pp.1187-1195
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    • 2022
  • To run the algorithm for identifying the segments of a pipe network, the relative positional relation between nodes, pipes, and valves should be prepared as input information of a segment search algorithm. In order to more accurately identify the segments of real pipe network, pipe network GIS/CAD database that contains all isolation valves is more suitable than modeled pipe network information used for a hydraulic analysis program. In this study, we developed an algorithm that can establish the relative positional relations among node-pipe-valve suitable for pipe network segment search algorithms using GIS/CAD data of a real water supply network, and developed a MATLAB program that can implement it. The effectiveness of the developed MATLAB program was confirmed by applying it to a portion of a real municipal pipe network.

Parametric Analysis of the Solar Radiation Pressure Model for Precision GPS Orbit Determination

  • Bae, Tae-Suk
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.35 no.1
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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.

Short-term Outcome of Benign Paroxysmal Positional Vertigo : Pilot Study (양성돌발성두위현훈의 단기적인 예후 : 예비연구)

  • Jeong, Sang-Wuk;Jang, Hyung Yeol;Kim, Kwang-Ki
    • Annals of Clinical Neurophysiology
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    • v.8 no.1
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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.

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Banhabaeckchulchunma-tang for Benign Paroxysmal Positional Vertigo: A Systematic Review and Meta-analysis (양성 발작성 자세변환성 현훈에 대한 반하백출천마탕(半夏白朮天麻湯)의 효과: 체계적 문헌고찰과 메타분석)

  • Kim, Geun-Lip;Hong, Chul-Hee;Lee, Kyou-Young
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.34 no.4
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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.

A study on the 3-D positional analysis for track of magnetically levitated vehicles (자기부상열차 선로의 3차원 위치해석에 관한 연구)

  • 강준묵;윤희천;배상호
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.13 no.2
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    • pp.229-236
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    • 1995
  • This study is the 3-D positional analysis for track of magnetically levitated vehicles to precise construction and periodical safe diagnosis by photogrammetry. In the result, we could improve the accuracy of Z as well as X, Y using the modified control points of spatial distribution to the plane distribution of the absolutly effective control points to accuracy and diagnosis the the track of magnetically levitated vehicles using the below 1㎜ accuracy. And we could analysis the 3-D precise positions and efficiently decide the geometric characteristics of the cant and gradient to the instrument.

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A Site Specific Characterization Technique and Its Application

  • Kamino, T.;Yaguchi, T.;Ueki, Y.;Ohnish, T.;Umemura, K.;Asayama, K.
    • 한국전자현미경학회:학술대회논문집
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    • 2001.11a
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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.

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