• Title/Summary/Keyword: Dead Space

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A Case of Pedicle Screw Loosening Treated by Modified Transpedicular Screw Augmentation with Polymethylmethacrylate

  • Kang, Suk-Hyung;Kim, Kyoung-Tae;Park, Seung-Won;Kim, Young-Baeg
    • Journal of Korean Neurosurgical Society
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    • v.49 no.1
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    • pp.75-78
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    • 2011
  • We report a case of pedicle screw loosening treated by modified transpedicular screw augmentation technique using polymethylmethacrylate(PMMA), which used the anchoring effect of hardened PMMA. A 56-year-old man who had an L3/4/5 fusion operation 3 years ago complained of continuous low back pain after this operation. The computerized tomography showed a radiolucent halo around the pedicle screw at L5. We augmented the L5 pedicle screw with modified pedicle screw augmentation technique using PMMA and performed an L3/4/5 pedicle screw fixation without hook or operation field extension. This modified technique is a kind of transpedicular stiffness augmentation using PMMA for the dead space around the loosed screw. After filling the dead space with 1-2 cc of PMMA, we inserted a small screw. Once the PMMA hardened, we removed the small screw and inserted a thicker screw along the existing screw threading to improve the pedicle screws' pullout strength. At 10 months' follow-up, x-ray showed strong fusion of L3/4/5. The visual analogue scale (VAS) of his back pain was improved from 9 to 5. This modified transpedicular screw augmentation with PMMA using anchoring effect is a Simple and effective surgical technique for pedicle screw loosening. However, clinical analyses of long-term follow-up and biomechanical studies are needed.

An Indexing Technique of Moving Point Objects using Projection (추출 연산을 활용한 이동 점 객체 색인 기법)

  • 정영진;장승연;안윤애;류근호
    • Journal of KIISE:Databases
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    • v.30 no.1
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    • pp.52-63
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    • 2003
  • Spatiotemporal moving objects are changing their Positions and/or shape over time in real world. As most of the indices of moving object are based on the R-tree. they have defects of the R-tree which are dead space and overlap. Some of the indices amplify the defects of the R-tree. In the paper, to solve the problems, we propose the MPR-tree(Moving Point R-tree) using Projection operation which has more effective search than existing moving point indices on time slice query and spatiotemporal range query. The MPR-tree connects positions of the same moving objects over time by using linked list, so it processes the combined query about trajectory effectively. The usefulness of the Projection operation is confirmed during processing moving object queries and in practical use of space from experimentation to compare MPR-tree with existing indices of moving objects. The proposed MPR-tree would be useful in the LBS, the car management using GPS, and the navigation system.

Treatment of Nonsyndromic Craniosynostosis Using Multi-Split Osteotomy and Rigid Fixation with Absorbable Plates

  • Nam, Su Bong;Nam, Kyeong Wook;Lee, Jae Woo;Song, Kyeong Ho;Bae, Yong Chan
    • Archives of Craniofacial Surgery
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    • v.17 no.4
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    • pp.211-217
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    • 2016
  • Background: Nonsyndromic craniosynostosis is a relatively common craniofacial anomaly and various techniques were introduced to achieve its operative goals. Authors found that by using smaller bone fragments than that used in conventional cranioplasty, sufficiently rigid bone union and effective regeneration capacity could be achieved with better postoperative outcome, only if their stable fixation was ensured. Methods: Through bicoronal incisional approach, involved synostotic cranial bone together with its surrounding areas were removed. The resected bone flap was split into as many pieces as possible. The extent of this 'multi-split osteotomy' depends on the degree of dysmorphology, expectative volume increment after surgery and probable dead space caused by bony gap between bone segments. Rigid interosseous fixation was performed with variable types of absorbable plate and screw. In all cases, the pre-operational three-dimensional computed tomography (3D CT) was checked and brain CT was taken immediately after the surgery. Also about 12 months after the operation, 3D CT was checked again to see postoperative morphology improvement, bone union, regeneration and intracranial volume change. Results: The bony gaps seen in the immediate postoperative brain CT were all improved as seen in the 3D CT after 12 months from the surgery. No small bone fragment resorption was observed. Brain volume increase was found to be made gradually, leaving no case of remaining epidural dead space. Conclusion: We conclude that it is meaningful in presenting a new possibility to be applied to not only nonsyndromic craniosynostosis but also other reconstructive cranial vault surgeries.

Policies of Trajectory Clustering in Index based on R-trees for Moving Objects (이동체를 위한 R-트리 기반 색인에서의 궤적 클러스터링 정책)

  • Ban ChaeHoon;Kim JinGon;Jun BongGi;Hong BongHee
    • The KIPS Transactions:PartD
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    • v.12D no.4 s.100
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    • pp.507-520
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    • 2005
  • The R-trees are usually used for an index of trajectories in moving-objects databases. However, they need to access a number of nodes to trace same trajectories because of considering only a spatial proximity. Overlaps and dead spaces should be minimized to enhance the performance of range queries in moving-objects indexes. Trajectories of moving-objects should be preserved to enhance the performance of the trajectory queries. In this paper, we propose the TP3DR-tree(Trajectory Preserved 3DR-tree) using clusters of trajectories for range and trajectory queries. The TP3DR-tree uses two split policies: one is a spatial splitting that splits the same trajectory by clustering and the other is a time splitting that increases space utilization. In addition, we use connecting information in non-leaf nodes to enhance the performance of combined-queries. Our experiments show that the new index outperforms the others in processing queries on various datasets.

Screening of Alstonia scholaris Linn. R. Br., for wound healing activity

  • S, Arulmozhi;VP, Rasal;Sathiyanarayanan, L;Ashok, Purnima
    • Advances in Traditional Medicine
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    • v.7 no.3
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    • pp.254-260
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    • 2007
  • Alstonia scholaris (Family: Apocynaceae) has been indicated for the treatment of various diseases, one among which is wound healing. The purpose of this study is to investigate the wound healing effect and antioxidant role of Alstonia scholaris leaves in animal models. The ethanol and aqueous extracts of Alstonia scholaris (EEAS, AEAS respectively) were tested against excision, incision and dead space wound models to evaluate the wound healing activity. In excision wound model, treatment was continued till the complete healing of wound, in incision and dead space wound models, the treatment was continued for 10 days. For topical application, 5% w/w ointment of EEAS and AEAS were prepared in 2% sodium alginate. For oral administration, EEAS was suspended in distilled water using Tween 80 and AEAS was dissolved in distilled water. The wound healing was assessed by the rate of wound contraction, period of epithelialisation, skin breaking strength, granulation strength, dry granulation tissue weight, hydroxyproline, collagen and histopathology of granulation tissue. Malondialdehyde level was also estimated to evaluate the extent of lipid peroxidation. AEAS and EEAS significantly promoted wound healing activity in all the wound models studied. Increase in the rate of wound contraction, skin breaking strength, granulation strength, dry granulation tissue weight, hydroxyproline and collagen, decrease in the period for epithelialisation and increased collagenation in histopathological section were observed with EEAS and AEAS treated groups. EEAS and AEAS also significantly decreased the levels of lipid peroxidation. The present study is suggestive that EEAS and AEAS promote wound healing activity.

Pleurodesis with Autologous Blood Plus Sclerosing Agents (자가혈과 늑막유착제를 이용한 늑막유착술 -치험 2례 보고-)

  • 송종필;이종호;김병열;이정호;강경민
    • Journal of Chest Surgery
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    • v.32 no.1
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    • pp.92-95
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    • 1999
  • The patients with prolonged air leak after lung resection surgery were generally treated by pleurodesis with sclerosing agents such as talc, tetracyclin, doxycyclin, bleomycin, vibramycin, and OK432. However, for the case like dead space resulted by incomplete reexpansion of the remaining lung, chemical pleurodesis has shown to be not as effective as expected. If the patients keep the chest tube for long period of time, the risk of thoracic empyema would increase. Most thoracic surgeons have experienced prolonged airleak which developed after lung resection. Pleurodesis with autoblood was reported as an effective method in treatment of patients with prolonged airleak. The mechanism of blood pleurodesis may be direct obliteration of BPF and reduction of dead space by clot. Therefore we successfully treated the two patients with prolonged airleak using the autoblood plus OK432 or vibramycin.

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ADAM: An Approach of Digital Asset Management system (사후 디지털 자산 관리 시스템에 관한 연구)

  • Moon, Jeong-Kyung;Kim, Hwang-Rae;Kim, Jin-Mook
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.9
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    • pp.1977-1982
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    • 2012
  • Social network service user or smart phone user is very convenient, because there are supported to various social network services such as Facebook, Twitter, Flickr, Naver blog, Daum blog, and so on. This Is very good because they store multimedia datas that user wants to cyber space if they want it conveniently. But, if social network user increases, space of cloud storage increases sharply, and when social network service used user dies then they have big problems such as they did not know in existing. Typically, problems of notice, dissemination, storage, and inheritance for digital asset can happen representatively. Now, If successor send relation information of he and his dead user that is family to social network service provider then service provider checks it. And successor may can use, save and only backup are possible after confirm of family relation truth. Therefore, We wish to propose ADAM that successor may can inherit digital assets easily, conveniently, and safely in this paper. If someone use ADAM, successor submits information about dead and own family relation in the third certification party. And ADAM can be inherited freely and conveniently about digital assets as general assets passing through right inheritance process.

Spatial Filtering Techniques for Geospatial AR Applications in R-tree (R-tree에서 GeoSpatial AR 응용을 위한 공간필터링 기법)

  • Park, Jang-Yoo;Lee, Seong-Ho;Nam, Kwang-Woo
    • Spatial Information Research
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    • v.19 no.1
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    • pp.117-126
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    • 2011
  • Recently, AR applications provide location-based spatial information by GPS. Also, the spatial information is displayed by the angle of the camera. So far, traditional spatial indexes in spatial database field retrieve and filter spatial information by the minimum bounding rectangle (MBR) algorithm.(ex. R-tree) MBR strategy is a useful technique in the geographic information systems and location based services. But MBR technique doesn't reflect the characteristics of spatial queries in AR. Spatial queries of AR applications have high possibility of the dead space area between MBRs of non-leaf node and query area. We propose triangle node filtering algorithm that improved efficiency of spatial retrieval used the triangle node filtering techniques by exclusion the dead space. In this paper, the proposed algorithm has been implemented on PostgreSQL/PostGIS. Experimental results show the spatial retrieval that using the proposed algorithm better performance than the spatial retrieval that of the minimum bounding rectangle algorithm.

RETROSPECTIVE CLINICAL STUDY OF TRACHEOSTOMY IN ORAL AND MAXILLOFACIAL SURGERY;31 CASES (구강외과 영역에 있어서의 기관절제술 31 례에 대한 임상적 고찰)

  • Yang, Yun-Seok;Min, Byung-Kook;Min, Seong-Kee;Um, In-Woong;Kim, Chang-Soo
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.13 no.1
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    • pp.53-62
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    • 1991
  • Tracheostomy may be used to assure airway protection in various clinical situation. It, as a known operation, has a history spanning 2000 years. The first clear account of a successful tracheostomy was recorded in 1546 by Brasavola. Until 1718 the term "bronchotomy" was used to describe the procedure. Heister then introduce the term "tracheotomy and this was later adopted and popularized by Trousseau about 1830. The term "tracheostomy" appeared in medical literature after 1820 and the two terms "tracheostomy" and "tracheotomy" are used interchangeably today. Indications include relief of upper airway obstruction, facilitation of pulmonary toilet, diminution of dead space and need for prolonged mechanical ventilation. The extent of indication of tracheostomy has a tendency to increase, thus oral and maxillofacial surgeons have some opportunities to face a situation that require tracheostomy. So, we reported retrospective study of 31 cases of tracheostomy patient in oral and maxillofacial surgery with reference review to reveal the significance of surgical skill and management capability of emergercy state maxillofacial surgery patients.

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The Monitoring System for Location of Workers Inside a Thermal Power Plant Boiler (화력 발전기 보일러 내부 작업자 위치 모니터링 시스템 개발)

  • Song K.;Yun, C.N.;Shin, Y.H.;Shin, J.H.;Han, S.H.;Jang, D.Y.
    • Journal of the Korean Society of Safety
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    • v.36 no.5
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    • pp.71-78
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    • 2021
  • There are regularly planned overhaul periods in thermal power plants, which involve the maintenance of the boiler of the power plants. However, thermal power plants workers are always exposed to risk during overhaul periods owing to the narrow space and significant dust inside the boiler. Therefore, it is essential to develop a safety monitoring system that is suitable for operating in this type of environment. In this study, we developed not only a worker three-dimensional (3D)-location monitoring system that can monitor and record the entry/exit of workers, their 3D-location, and fall accidents but also a method to secure the working environment and operation efficiency. This system comprises of a worker tag, which was equipped with an inertial measurement unit, a barometric pressure sensor, and a Bluetooth low energy (BLE), and the tags were given to each worker. In addition, the location of workers inside the boiler was measured using a pedestrian dead reckoning (PDR) method and BLE beacons. The location data of the workers tag were transmitted to the integrated database (DB) server through a gateway, and to the administrator monitoring system. The performance of the system was demonstrated inside an actual thermal power plant boiler, and the accuracy and reliability of the system were verified through a number of repeated tests. These results provide insights on designing a new system for monitoring enclosed spaces.