• Title/Summary/Keyword: leakage control

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A system for detecting document leakage by insiders through continuous user authentication by using document reading behavior (문서 읽기 행위를 이용한 연속적 사용자 인증 기반의 내부자 문서유출 탐지기술 연구)

  • Cho, Sungyoung;Kim, Minsu;Won, Jongil;Kwon, SangEun;Lim, Chaeho;Kang, Brent ByungHoon;Kim, Sehun
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.23 no.2
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    • pp.181-192
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    • 2013
  • There have been various techniques to detect and control document leakage; however, most techniques concentrate on document leakage by outsiders. There are rare techniques to detect and monitor document leakage by insiders. In this study, we observe user's document reading behavior to detect and control document leakage by insiders. We make each user's document reading patterns from attributes gathered by a logger program running on Microsoft Word, and then we apply the proposed system to help determine whether a current user who is reading a document matches the true user. We expect that our system based on document reading behavior can effectively prevent document leakage.

A Study on the Ventilation Schemes for Gas Leakage and Dispersion Controlling at the Backfilled Working Face in Large-Opening Underground Mine (대단면 지하광산 갱도내 뒷채움 작업장 가스유출 및 확산제어 통기방안 연구)

  • Nguyen, Vanduc;Lee, Changwoo
    • Tunnel and Underground Space
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    • v.28 no.4
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    • pp.372-386
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    • 2018
  • The air quality near the backfilled site area is significantly deteriorated during and even after the curing period of the backfill materials. Hazardous gases such as NH3 and CO2 may leak out prolongedly from the mined-out sites backfilled with the composite carbonate-based material; leakage can be observed at the underground working sites as well as on the surface. At operating mines, underground gas leakage will severely aggravate the workplace environment. The ventilation schemes should supply sufficient air to dilute the contaminated air, and control the toxic gas leakage and dispersion. This study shows the applicability of pressurization ventilation system to control gas leakage and dispersion at the backfilled underground mine site.

Development of Remote Supervision System for Guam Lamps by Way of Leakage Current(Igr) Detection Method (보안등 전거설비의 Igr 누설전류 검출 및 원격감시장치 개발)

  • Choi, Myeong-Il;Kim, Young-Seok;Kim, Chong-Min;Bang, Sun-Bae
    • Journal of the Korean Society of Safety
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    • v.25 no.6
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    • pp.75-80
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    • 2010
  • The present study presented the implementation of a remote control/supervision system for guard lamps used in public illumination with little endeavor by far for safe management, which makes possible to supervise the state and to control the functions remotely including electric safety elements. Especially, the developed system adopts the measurement algorithm for detecting resistive leakage current(Igr) flowing based on the phase difference checkable for sensing at a monitor, being allowable for monitoring at MMI and transmitter for data transmittance. To verify reliability about the algorithm to accurately detect Igr leakage current, the laboratory-based functional test was performed.

Research of Sludge Quantity and Evaluation of Sludge Handling Facilities in Water Treatment Plants (정수 슬러지 발생량 조사 및 슬러지 처리시설의 공정평가)

  • Moon, Seong-Yong;Kim, Seung-Hyun
    • Journal of Korean Society of Water and Wastewater
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    • v.18 no.3
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    • pp.279-290
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    • 2004
  • Sludge quantity has increased at "A"water treatment plant due to deterioration of raw water quality and GAC installation. Increased sludge resulted in overloading on sludge handling facilities. The object of this study is to survey sludge quantity and capacity of sludge handling facilities at "A"water treatment plant. Measured quantity of sedimentation sludge considerably exceeded the design capacity of sludge holding basin. Sludge holding basin was properly designed, but low concentration of sludge discharged from sedimentation basin caused production of large volume of the sludge. Timer operated control system for sludge withdrawal unit and leakage through a control valve were suspected to cause the low concentration. Augmentation of the control system by a turbidity meter and addition of a new control valve successfully reduced the sludge volume enough to satisfy the design capacity of sludge holding basin. Unlike sedimentation sludge, measured quantity of washwater was considerably less than the design capacity of washwater basin because it was over-designed.

Operating Method of 3 Phase Voltage type PWM Converter for Unbalanced Voltage with Leakage Transformer (누설변압기가 부착된 전원 불평형 3상 전압형 PWM 컨버터 운전법)

  • Chun, Ji-Yong;Kim, Young-Chun;Cho, Yu-Hwan;Lee, Keun-Hong
    • Proceedings of the KIPE Conference
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    • 2005.07a
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    • pp.125-127
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    • 2005
  • In this paper, the control algorithm of DC source device for inverter starting is proposed and the control method for compensating unbalance system source on operating time in the voltage type PWM converter with driving and regenerative faculty is suggested. The maintaining way of balancing condition for converter of AC source is used the compensating unbalanced status by current control loop. Because it is possible that the unbalanced System control is used to leakage transformer not equaled reactance by each phase in rectifier system, the proposed H/W and control algorithm of rectifier system is contributed to minimize of device and rising efficiency.

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Outcomes of Non-Operative Treatment for Duodenal Stump Leakage after Gastrectomy in Patients with Gastric Cancer

  • Ali, Bandar Idrees;Park, Cho Hyun;Song, Kyo Young
    • Journal of Gastric Cancer
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    • v.16 no.1
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    • pp.28-33
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    • 2016
  • Purpose: We evaluated the clinical outcomes of the non-operative management of post-gastrectomy duodenal stump leakage in patients with gastric cancer. Materials and Methods: A total of 1,230 patients underwent gastrectomy at our institution between 2010 and 2014. Duodenal stump leakage was diagnosed in 19 patients (1.5%), and these patients were included in this study. The management options varied with patient condition; patients were managed conservatively, with a pigtail catheter drain, or by tube duodenostomy via a Foley catheter. The patients' clinical outcomes were analyzed. Results: Duodenal stump leakage was diagnosed in all 19 patients within a median of 10 days (range, 1~20 days). The conservative group comprised of 5 patients (26.3%), the pigtail catheter group of 11 patients (57.9%), and the Foley catheter group of 3 patients (15.8%). All 3 management modalities were successful; none of the patients needed further operative intervention. The median hospital stay was 18, 33, and 42 days, respectively. Conclusions: Non-operative management of duodenal stump leakage for selected groups of patients with gastric cancer was effective for control of intra-abdominal sepsis. This management modality can help obviate the need for surgical intervention.

LEAKAGE EVALUATION OF SEVERAL SEALERS USING ANAEROBIC BACTERIAL LEAKAGE MODEL (혐기성세균모델을 이용한 봉함제(Sealer)의 미세누출에 관한 연구)

  • Bae, Yong-Kue;Oh, Tae-Suk;Yoon, Soo-Han
    • Restorative Dentistry and Endodontics
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    • v.25 no.2
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    • pp.235-242
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    • 2000
  • The purpose of this in vitro study was to evaluate the sealing ability of three sealers(Sealapex, Pulp canal sealer, AH26) used with continuous wave method using an anaerobic bacterial leakage model. 53 extracted human teeth with straight and single canals were prepared with crown-down pressureless technique using .04, .06 taper Profile(Maillefer, Swiss). Master apical file was maintained as #35 K-file. All canals of the experimental teeth were obturated with continuous wave method using System B(Analytic technology, U.S.A.) The teeth were randomly divided into three experimental groups of 15 and two control groups of 4. Experimental group 1 was obturated with Sealapex and group 2 with Pulp canal sealer, and group 3 with AH26. A dual chamber anaerobic bacterial leakage model was assembled. Brain heart infusion with yeast extract, hemin, menadion, and the chromogenic indicator bromocresol purple was used as the culture broth for Fusobacterium nucleatum(VPI 10197), The specimens were incubated in anaerobic chamber at $37^{\circ}C$ and were observed every 2 to 3 clays, The coronal leakage was evaluated through the color change of culture broth in lower chamber for 60 days. The results were as follows: 1. The incidence of bacterial leakage in group 1 (Sealapex group was 80%, 53% in group 2 (Pulp canal sealer), 27% in group 3 (AH26). 2. There were statistically significant differences in leakage scores between group 1 and group 2, and between group 1 and group 3, respectively. (P<0.05) 3. There was no significantly difference in leakage score between group 2 and group 3. (P>0 05)

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A STUDY ON THE EFFECT OF BASE MATERIALS TO PROTECT THE CERVICAL LEAKAGE OF BLEACHING AGENTS (표백제의 치경부 누출을 방지하기 위한 각종 이장재의 효과에 관한 연구)

  • Song, Byeong-Choon;Cho, Young-Gon
    • Restorative Dentistry and Endodontics
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    • v.19 no.2
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    • pp.585-601
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    • 1994
  • The purpose of this study was to evaluate the ability of several intracoronal base materials to prevent cervical leakage of a bleaching agent into the dentinal tubules and along the root canal. In this study, thirty-two anterior teeth were used. After lingual access was prepared in each tooth, tooth was instrumented with a step-back technique to a Nos. 40-50 using K-type files. All teeth were obturated with a lateral condensation technique. Excess gutta percha was removed with a warm instrument to the facial level of the CEJ. Teeth were divided into four groups : Teeth in control group were not filled with base material. Teeth in groups 1, 2, and 3 had 2mm of gutta percha removed with a warm instrument, then Dycal, Fuki II LC and Z-100 were filled with palstic instruments on the top of the gutta percha respectively. All teeth were bleached for 7 days, fresh bleach was added for another 7 days, then a 10 % methylene blue dye was placed inside the access preparation. They were stored at $37^{\circ}C$ and $100^{\circ}C$ humidity for 5 days. Each tooth was sectioned perpendicular to the long axis using a diamond disk. Initial cuts were made at the most coronal level of facial and lingual CEJ's, then another cuts continued appically in the levels of 0.5mm, 1.5mm, and 2.0mm respectively. The amount of dye leakage through the dentinal tubules was determined at each cut section. In addition, when the cut specimen was determined to be last penetration of any dye, this level was recorded as depth of apical leakage from the coronal terminus of the gutta percha, Dycal, Fuji II LC and Z-100. The acquired data were analyzed by Tukey's Multiple Range Test adn Cochran-Mantel-Haenszel Test to see if there was any statistically significant difference in dye penetration and linear apical leakage among the groups. The results were as follows : 1. Control group at levels of CEJ and 0.5mm, group 3 at level of 1.5mm, and group 2 AND 3 at level of 2.0mm showed the least dye penetration through the facial or lingual dentinal tubules, but there were no significant difference among three groups. 2. Group 2 at levels of CEJ and 0.5mm, group 3 at level of 1.5mm, and group 2 and 3 at level of 2.0mm showed the least dye penetration through the proximal dentinal tubules, but there were no significant difference among control group, group 2, and group 3. 3. Group 1 showed the greatest dye penetration through the facial or lingual and proximal dentinal tubules at all levels, and there were significant difference with other three groups. 4. Control group and group 1 showed 2mm apical dye leakage at facial or lingual and proximal aspects, group 2 showed 1.5mm, and group 3 showed 0.5mm.

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A STUDY ON THE MARGINAL LEAKAGE OF RESTORATIONS WITH DIFFERENT CAVOSURFACE MARGINS (와연형태(窩緣形態)에 따른 와연누출(邊緣漏出)에 관(關)한 실험적(實驗的) 연구(硏究))

  • Shin, Han-Ju;Choi, Ho-Young;Min, Byung-Soon;Park, Sang-Jin
    • Restorative Dentistry and Endodontics
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    • v.12 no.1
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    • pp.119-129
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    • 1986
  • The purpose of this study was to evaluate the marginal leakage of glass ionomer cement with different cavosurface margins. 192 class V cavities were prepared on freshly extracted non-carious teeth and glass ionomer cement were inserted according to the manufacturer's instructions. Cavity preparations for this investigation were performed in four groups. The experimental specimens were made by packing the glass ionomer cement (Fuji Ionomer Type II G-C Co. Japan) into the prepared 192 cavities of four groups with different modes: Group I. - The 48 cavities with $90^{\circ}$ butt-joint cavosurface preparation and restored with glass ionomer cement. Group II. - The 48 cavities with butt-joint preparation modified by $135^{\circ}$ beveling the cavosurface in the dentin and restored with glass ionomer cement. Group III. - The 48 cavities with butt-joint preparation modified by cutting a chamfer in the dentin and restored with glass ionomer cement. Group IV. - The same 48 cavities as group I, and overfilled with glass ionomer cement beyond the cavosurface angle. And four groups above described divided into three subgroups by means of conditioning the cavity walls: Control group. - Glass ionomer cement filled in the prepared 64 cavities after being cleaned with a stream of tap water. Phosphoric acid treatment group. - Glass ionomer cement filled in the prepared 64 cavities after being conditioned with a 50% phosphoric acid. Citric acid treatment group. - Glass ionomer cement filled in the prepared 64 cavities after being conditioned with a 50% citric acid. All 192 specimens were immersed in the 2.0% basic fuchsin solution and subjected to thermal stress at one-minute intervals ($4{\pm}2^{\circ}C$ to $60{\pm}2^{\circ}C$) for 70 minutes before exposure to the dye. The specimens were sectioned ecclesiologically through the center of the restorations for different periods of immersion time, 24 hours, 7 days, 14 days 30 days. The sections were examined under a stereoscopic microscope. The results were as follows: 1. The degree of marginal leakage in group II and III was greater than that in group I and IV. 2. The degree of marginal leakage in phosphoric acid treatment group was similar with that in control group. 3. The degree of marginal leakage in citric acid treatment group was less than that in control group. 4. In all groups, the degree of marginal leakage in phosphoric acid treatment group was greater than that in citric acid treatment group. 5. There is no statistical difference of the degree of marginal leakage according to the immersion time in the dye solution.

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Oxidative Stress and Antioxidant Responses in Poplar Clones Irrigated with Livestock Waste Leachate (양돈폐수 처리에 의한 포플러클론의 산화스트레스와 항산화반응)

  • Je, Sun-Mi;Yeo, Jin-Gi;Woo, Su-Young
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.13 no.3
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    • pp.140-147
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    • 2011
  • We studied the influence of livestock waste leachate on oxidative damage and antioxidative responses in poplar clones in August which increase the demand of antioxidants because of high temperature and high light during this period. We measured ion leakage, antioxidant enzyme activities (APX, GR), and carotenoid contents. Oxidative damage and antioxidative responses by treated livestock waste leachate in poplar clones showed various results. We divided poplar clones into three groups using the criteria based on ion leakage which represent cell damage induced oxidative stress. Eco 28, 62-10, Bonghwa1 and Dorskamp belonged to the first group in which the cell damaged level was lower than that of the control. The results suggest that this group augmented for demand of antioxidative in summer because high concentration of nitrogen induced by treatment of live stock wastes acted as environmental stress. Consequently, they failed to keep up the homeostasis of reactive oxygen species. The second group in which the cell damaged level was similar to that of the control was Suwon, 72-30 and 72-31 clones. Finally, 97-18 clone belonged to the third group in which the cell damaged level was lower than that of the control group. In this case, nitrogen treated by livestock waste leakage decreased oxidative stress. 97-18 clone was the clones with the least damage in summer oxidative stresses treated by livestock waste leakage. These results suggest that the high concentration nitrogen due to the livestock waste leakage can act differently upon the clones. We speculate that the added oxidation damage in the summer (growing season) may have an effect on the total fresh weight and also influence the purification ability for livestock waste leakage. However, further studies are needed for the confirmation.