• Title/Summary/Keyword: Temporary

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POLYMERIZATION SHRINKAGE, HYGROSCOPIC EXPANSION AND MICROLEAKAGE OF RESIN-BASED TEMPORARY FILLING MATERIALS (레진계 임시수복재의 중합수축, 수화팽창과 미세누출)

  • Cho, Nak-Yeon;Lee, In-Bog
    • Restorative Dentistry and Endodontics
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    • v.33 no.2
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    • pp.115-124
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    • 2008
  • The purpose of this study was to measure the polymerization shrinkage and hygroscopic expansion of resin-based temporary filling materials and to evaluate microleakage at the interface between the materials and cavity wall. Five resin-based temporary filing materials were investigated: Fermit (Vivadent), Quicks (Dentkist), Provifil (Promedica), Spacer (Vericom), Clip (Voco). Caviton (GC) was also included for comparison. Polymerization shrinkage of five resin-based temporary filling materials was measured using the bonded disc method. For the measurement of hygroscopic expansion, the discs of six cured temporary filling materials were immersed in saline and a LVDT displacement sensor was used to measure the expansion for 7 days. For estimating of microleakage, Class I cavities were prepared on 120 extracted human molars and randomly assigned to 6 groups of 20 each. The cavities in each group were filled with six temporary filling materials. All specimens were submitted to 1000 thermocycles, with temperature varying from $5^{\circ}C/55^{\circ}C$. Microleakage was determined using a dye penetration test. The results were as follows: 1. Fermit had significantly less polymerization shrinkage than the other resin-based temporary fill ing materials. Fermit (0.22%) < Spacer (0.38%) < Quicks (0.64%), Provifil (0.67%), Clip (0.67%) 2. Resin-based temporary filling materials showed 0.43-1.1% expansion in 7 days. 3. Fermit showed the greatest leakage, while Quicks exhibited the least leakage. 4. There are no correlation between polymerization shrinkage or hygroscopic expansion and microleakage of resin-based temporary filling materials.

Risk of Stroke with Temporary Arterial Occlusion in Patients Undergoing Craniotomy for Cerebral Aneurysm

  • Ha, Sung-Kon;Lim, Dong-Jun;Seok, Bong-Gil;Kim, Se-Hoon;Park, Jung-Yul;Chung, Yong-Gu
    • Journal of Korean Neurosurgical Society
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    • v.46 no.1
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    • pp.31-37
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    • 2009
  • Objective : This study was performed to elucidate the technical and patient-specific risk factors for postoperative ischemia in patients undergoing temporary arterial occlusion (TAO) during the surgical repair of their aneurysms. Methods : Eighty-nine consecutive patients in whom TAO was performed during surgical repair of an aneurysm were retrospectively analyzed. The demographics of the patients were analyzed with respect to age. Hunt and Hess grade on admission, Fisher grade of hemorrhage, aneurysm characteristics, timing of surgery, duration of temporary occlusion, and number of temporary occlusive episodes. Outcome was analyzed at the 3-month follow-up, along with the occurrence of symptomatic and radiological stroke. Results : In overall, twenty-seven patients (29.3%) had radiologic ischemia attributable to TAO and fifteen patients (16.3%) had symptomatic ischemia attributable to TAO. Older age and poor clinical grade were associated with poor clinical outcome. There was a significantly higher rate of symptomatic ischemia in patients who underwent early surgery (p=0.007). The incidence of ischemia was significantly higher in patients with TAO longer than 10 minutes (p=0.01). In addition, patients who underwent repeated TAO, which allowed reperfusion, had a lower incidence of ischemia than those who underwent single TAO lasting for more than 10 minutes (p=0.011). Conclusion : Duration of occlusion is the only variable that needs to be considered when assessing the risk of postoperative ischemic complication in patients who undergo temporary vascular occlusion. Attention must be paid to the patient's age, grade of hemorrhage, and the timing of surgery. In addition, patients undergoing dissection when brief periods of temporary occlusion are performed may benefit more from intermittent reperfusion than continuous clip application. With careful planning, the use of TAO is a safe technique when used for periods of less than 10 minutes.

The Characteristics of Structural Behavior of Temporary Bridge Using Continuous Cross Beam (일체형 가로보를 이용한 임시교량의 구조적 거동특성)

  • Joo, Hyung-Joong;Lee, Young-Geun;Lee, Dong-Hyuk;Yoon, Soon-Jong
    • Journal of Korean Society of Steel Construction
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    • v.24 no.5
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    • pp.559-569
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    • 2012
  • Cross-beam in the existing temporary bridge system is usually installed to prevent the lateral-torsional buckling of girders and to promote the construction efficiency. However, most of this cross-beams are connected to the girder web by bolts, and therefore, gravitational load resisting capacity of the cross-beams are negligibly small. In recent years, new temporary bridge system, in which the cross-beams and girders are connected to resist the external loads as a unit, was developed. In this paper, we present the experimental and analytical study results pertaining to the structural behavior and load carrying capacity of new temporary bridge system. From the results of study, it was found that the continuous cross-beam increased the flexural rigidity and reduced the maximum flexural stress in the girder. In addition, it was also found that the new temporary bridge system developed is more appropriate for the application in the long-span temporary bridge.

A Study on the Temporary Space Use for Urban Regeneration Strategy (도시재생 전략으로서 일시적 공간 활용에 관한 연구)

  • Lee, Do Kyoung;Kim, Jong Gu
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.40 no.2
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    • pp.247-255
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    • 2020
  • Currently, urban regeneration is carried out mostly in a permanent and fixed way of planning, and due to the nature of the master plan, it is limited to immediately accepting the opinions of residents. In this study, the factors of idle space were derived based on a temporary use strategy, and the direction of idle space was presented by comparing the importance of experts with the survey of residents' perceptions and preferences. As a result, residents preferred to improve the aging physical environment first because of the target location characteristics, while experts ranked it in line to reflect the importance of the use of temporary uses that can quickly improve the urban environment. Therefore, it is desirable to recognize the importance of the temporary use strategy and to refine the priorities of the two groups and conduct a temporary test to derive the optimal utilization measures and reflect them in the master plan. In order to implement a temporary use strategy in the future, it is necessary to present a space utilization plan that reflects detailed prior investigation through analysis of target location characteristics and usage patterns.

Coronal microleakage of four temporary restorative materials in Class II-type endodontic access preparations

  • Yun, Sang-Mi;Karanxha, Lorena;Kim, Hee-Jin;Jung, Sung-Ho;Park, Su-Jung;Min, Kyung-San
    • Restorative Dentistry and Endodontics
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    • v.37 no.1
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    • pp.29-33
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    • 2012
  • Objectives: The purpose of this study was to evaluate the microleakage of 4 temporary materials in teeth with Class II-type endodontic access preparations by using a glucose penetration model. Materials and Methods: Glucose reaction test was performed to rule out the presence of any reaction between glucose and temporary material. Class II-type endodontic access preparations were made in extracted human premolars with a single root (n = 10). Each experimental group was restored with Caviton (GC), Spacer (Vericom), IRM (Dentsply-Caulk), or Fuji II(GC). Microleakage of four materials used as temporary restorative materials was evaluated by using a glucose penetration model. Data were analyzed by the one-way analysis of variance followed by a multiplecomparison Tukey test. The interface between materials and tooth were examined under a scanning electron microscope (SEM). Results: There was no significant reaction between glucose and temporary materials used in this study. Microleakage was significantly lower for Caviton and Spacer than for Fuji II and IRM. SEM observation showed more intimate adaptation of tooth-restoration interfaces in Caviton and Spacer than in IRM and Fuji II. Conclusions: Compared to IRM and Fuji II, Caviton and Spacer can be considered better temporary sealing materials in Class II-type endodontic access cavities.

Assessment of Treatment Outcome after Using Temporary Mandibular Advancement Devices in Obstructive Sleep Apnea Patients (폐쇄성 수면 무호흡 환자에서 임시 하악 전방 이동 장치를 이용한 치료결과 분석)

  • Park, Joon-Hyung;Oh, Suseok;Hong, Jongrak;Kim, Chang-Soo;Paeng, Jun-Young
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.34 no.6
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    • pp.426-431
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    • 2012
  • Purpose: The aim of this study was to evaluate the effect of temporary mandibular advancement devices (MAD) in obstructive sleep apnea (OSA) patients Methods: 28 patients (male 21, female 7) undergoing temporary mandibular advancement device treatment for OSA were selected from 2011.01. to 2012.02. in the department of Oral & Maxillofacial Surgery at SamsungMedicalCenter. Treatment efficacy was determined by polysomnography (PSG) at baseline & after MAD delivery. The response group was defined as >50% Apnea-Hypopnea Index (AHI) reduction plus post-MAD AHI <10, and the non-response group was defined as <50% AHI reduction. The lateral cephalogram was analysed including SNA, SNB, UL, MPH, PAS, PASU, and PAST using V-ceph$^{TM}$ (Cybermed, USA). Results: The responsers were 23 patients, and non-responsers were 5 patients. The AHI was significantly reduced with temporary MAD ($8.08{\pm}7.93$) compared with baseline ($28.51{\pm}20.56$) in the response group (n=23). No significant difference was observed between pre MAD and post MAD except SNB on cephalometric analysis. Among 11 patients successfully treated with the temporary device, 9 patients said that using permanent device brings better effect too. Conclusion: These results indicate that the Temporary MAD could not be the only effective tools on OSA but also be used to predict patient's reactivity about permanent appliance treatment. Further studies are warranted to evaluate the relations between temporary MAD and permanent MAD.

The Planning of Temporary Housing for Post Application of Mega Sports Facilities - Focused on the 2018 Winter Olympics - (메가스포츠시설의 사후 활용을 위한 임시주거 계획 - 2018평창동계올림픽을 중심으로 -)

  • Lee, Jong-Chan;Kang, Youn-Do;Kim, Byung-Sean
    • KIEAE Journal
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    • v.16 no.4
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    • pp.41-46
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    • 2016
  • Purpose: This is a study on the planning of temporary housing for post application of Mega Sports facilities. The subject of the study is 2018 Pyeongchang Winter Olympics, which is to suggest building an alternative temporary housing using shipping containers(high cube), which solve the lack of accommodations and recycle temporary housing after Olympics, save money and be eco-friendly in Olympics. Method: This study includes this ; research on the a fact-finding survey about Mega sports facilities post application and demand survey on 2018 Pyeongchang Winter Olympics accomodations and an analysis about temporary housing plan. Furthermore we decided temporary housing building plan by analyzing residents' needs and traits of the housing etc. Through this, we made a schematic design for household units. Result: As a result, this study is a plan of making space, forms, and structure. The planned size is $38.4m^2$(L:12m, W:3.2m) except balcony, and indoor height is 2.5m. The space consists of entrance, bathroom, bedroom and living room with folding furniture system. Also there's a detailed floor plan of the ceiling, wall, and floor we drew up. The ceiling and wall consist of dampproof film, noncombustible board, fire proof urethane form, and color-designed sheet. The floor is composed of floor tile, cement mortar, light concrete(with heat coil), insulation, and dampproof film. Additionally, this study is a plan of interior dry wall with detail using modular construction method for work efficiency and quality improvement.

A Study on Development of Electronic Performance Support System Prototype for Improving the Efficiency of Quality Inspection of Temporary Work (가설공사 품질점검 업무효율 향상을 위한 전자작업지원시스템(EPSS) 프로토타입 개발에 관한 연구)

  • Yoon, Soo-Ho;Choi, Chang-Hoon;Han, Choong-Hee;Lee, Junbok
    • Korean Journal of Construction Engineering and Management
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    • v.20 no.2
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    • pp.13-27
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    • 2019
  • While temporary construction work applies to a temporary facility, it has a high use frequency during the construction period accounting for around 10% of the construction cost, it requires systematic management. However, construction inspection information of temporary construction work often has no special specification in the design documents and specification items, with the items on various standards also being formidable. Because of this, related inspection are likely to be performed inefficiently with a high probability for occurrence of human errors when quality inspection is conducted for the temporary construction work. In the present study, therefore, apply to the electronic operation support system capable of supporting implementation of inspection of providing related information for the contemporary construction work. To achieve this, a prototype is developed by using IDEF0 to identify information flow by process and organizing EPSS-based quality inspection Task. And then, efficiency of the quality inspection and information accessibility for temporary construction work are to be improved by verification method of Sample Project.

Comparison of three-dimensional adaptation as per the rinsing time of temporary crown manufactured using a digital light processing printer (디지털 광 조명 방식으로 제작한 임시 크라운의 세척 시간에 따른 3차원 적합도 평가)

  • Lee, Beom-Il;You, Seung-Gyu;You, Seung-Min;Kim, Ji-Hwan
    • Journal of Technologic Dentistry
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    • v.42 no.4
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    • pp.334-340
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    • 2020
  • Purpose: This study aimed to compare three-dimensional adaptation with the rinsing time of the temporary crown produced using the digital light processing method. Methods: The maxillary right first molar abutment was scanned with a dental scanner. A temporary crown was designed with the scanned abutment. The designed crown was made of 10 temporary crowns using a digital light processing printer. The crowns were divided into the 5-minute and 10-minute rinsing groups; 5 temporary crown washes were performed for each group. In order to obtain the internal data, each group was scanned for a temporary crown. The three-dimensional fit was measured by superimposing the scanned internal surface data and the abutment data. The average comparison of three-dimensional adaptation was analyzed using the Mann-Whitney U test. Results: The 5-minute rinsing group showed a significantly higher adaptation of 71.42±3.08 ㎛ as compared to the 10-minute rinsing group (67.52±0.92 ㎛) (p<0.05). Conclusion: When making a temporary crown with a digital light processing method, a rinsing time of 10 minutes is appropriate.

Block Allocation Method for Efficiently Managing Temporary Files of Hash Joins on SSDs (SSD상에서 해시조인 임시 파일의 효과적인 관리를 위한 블록 할당 방법)

  • Joontae, Kim;Sangwon, Lee
    • KIPS Transactions on Computer and Communication Systems
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    • v.11 no.12
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    • pp.429-436
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    • 2022
  • Temporary files are generated when the Hash Join is performed on tables larger than the memory. During the join process, each temporary file is deleted sequentially after it completes the I/O operations. This paper reveals for that the fallocate system call and file deletion-related trim options significantly impact the hash join performance when temporary files are managed on SSDs rather than hard disks. The experiment was conducted on various commercial and research SSDs using PostgreSQL, a representative open-source database. We find that it is possible to improve the join performance up to 3 to 5 times compared to the default combination depending on whether fallocate and trim options are used for temporary files. In addition, we investigate the write amplification and trim command overhead in the SSD according to the combination of the two options for temporary files.