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콜드 부트 공격 기술 및 최신 동향 분석

  • Won, Yoo-Seung;Han, Dong-Guk
    • Review of KIISC
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    • v.31 no.1
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    • pp.7-14
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    • 2021
  • 일반·보안 기기에서 개인 정보 및 비밀 정보가 많은 부분에서 취급된다. 보안 기기라고 할지라도 전원이 인가되지 않으면 데이터가 초기화되는 RAM의 물리적 특성을 고려하여, 보안영역으로 간과될 수 있다. 하지만 2008년 이후, RAM의 표면 온도를 현저히 낮추면 전원이 인가되지 않아도 RAM 데이터가 초기화되지 않는 특징을 활용한 콜드 부트 공격이 제기되어, 지금까지 활발히 연구되어 하나의 보안이 필요한 영역으로 자리매김하고 있다. 본 논문에서는 콜드 부트 공격의 방법론과 발전 동향, 콜드 부트 공격에 대한 물리적 특성 및 디스크 암호화 솔루션에 적용 가능한 콜드 부트 공격을 설명한다. 또한, 국내 연구에 간과될 수 있는 콜드 부트 공격을 고취시키기 위하여, 이에 대한 대응기법도 소개한다.

Study on Performance of Caching Algorithms for Mapping Table in Flash-based Storage Devices (플래시 기반 저장장치에서 사상 테이블의 캐싱 알고리즘 성능 연구)

  • Yang, Soo-Hyeon;Ryu, Yeon-Seung
    • Annual Conference of KIPS
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    • 2011.04a
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    • pp.17-20
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    • 2011
  • NAND 플래시 메모리 기반의 저장장치의 내부에는 Flash Translation Layer (FTL)이라는 소프트웨어가 사용되고 있다. FTL은 파일 시스템으로부터 요청되는 논리 주소를 플래시 메모리의 물리 주소로 변환하며 이를 위하여 사상 테이블을 사용한다. 일반적으로 사상 테이블의 빠른 접근을 위하여 사상 테이블은 저장장치 내부의 RAM에 유지한다. 최근 저장 공간의 용량이 커지게 되면서 사상 테이블로 인해 요구되는 RAM의 크기도 커지게 되어 사상 테이블을 플래시 메모리에 저장하고 일부만 RAM에 유지하는 캐싱 기법들이 연구되어 왔다. 본 논문에서는 SAT-c 라는 사상 테이블 캐싱 기법을 제안하고 캐시 교체 알고리즘들의 성능을 비교하였다.

Surgical management of hilar cholangiocarcinoma: Controversies and recommendations

  • Suvendu Sekhar Jena;Naimish N Mehta;Samiran Nundy
    • Annals of Hepato-Biliary-Pancreatic Surgery
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    • v.27 no.3
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    • pp.227-240
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    • 2023
  • Hilar cholangiocarcinomas are highly aggressive malignancies. They are usually at an advanced stage at initial presentation. Surgical resection with negative margins is the standard of management. It provides the only chance of cure. Liver transplantation has increased the number of 'curative' procedures for cases previously considered to be unresectable. Meticulous and thorough preoperative planning is required to prevent fatal post-operative complications. Extended resection procedures, including hepatic trisectionectomy for Bismuth type IV tumors, hepatopancreaticoduodenectomy for tumors with extensive longitudinal spread, and combined vascular resection with reconstruction for tumors involving hepatic vascular structures, are challenging procedures with surgical indications expanded. Liver transplantation after the standardization of a neoadjuvant protocol described by the Mayo Clinic has increased the number of patients who can undergo operation.

Portal cavernoma cholangiopathy: Update and recommendations on diagnosis and management

  • Ruchir Bhavsar;Amitabh Yadav;Samiran Nundy
    • Annals of Hepato-Biliary-Pancreatic Surgery
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    • v.26 no.4
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    • pp.298-307
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    • 2022
  • Portal cavernoma cholangiopathy is defined as an obstruction of the biliary system due to distended veins surrounding bile ducts that mainly occur in patients with extrahepatic portal venous obstruction. The periductal venous plexuses encircling the ducts can cause morphological changes which may or may not become symptomatic. Currently, non-invasive techniques such as ultrasonography, computed tomography, magnetic resonance cholangiopancreatography, and dynamic contrast enhanced magnetic resonance images are being used to diagnose this disorder. Only a few patients who have symptoms of biliary obstruction require drainage which might be accomplished using endoscopic stenting, decompression of the portal venous system usually via a lienorenal shunt, a difficult direct hepaticojejunostomy, and rarely a liver transplant.

Development of Embedded Fast/Light Phoneme Recognizer for Distributed Speech Recognition (분산음성인식을 위한 내장형 고속/경량 음소인식기 개발)

  • Kim, Seung-Hi;Hwang, Kyu-Woong;Jeon, Hyun-Bae;Jeong, Hoon;Park, Jun
    • Annual Conference of KIPS
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    • 2007.05a
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    • pp.395-396
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    • 2007
  • ETRI 음성/언어정보연구센터에서는 분산음성인식을 위해 메모리를 작게 사용하며 속도가 빠른 음소인식기를 개발 중이다. 음향 모델, 언어 모델, 탐색 네트워크 등 고정되어 있는 정보는 인식기를 수행하기 이전에 미리 binary 형태로 구축하여 ROM 형태로 저장함으로써 실제 사용해야 할 RAM 용량을 대폭 줄일 수 있었다. Tied state에 기반한 triphone 모델에서는 unique HMM 만을 사용함으로써 인식시간 및 메모리 사용량을 대폭 줄일 수 있었다. Monophone 인식기의 경우 RAM 사용량이 179KB였으며, triphone 인식기의 경우 435KB의 RAM 사용량과 RTF(Real Time Factor) 0.02를 확인하였다.

A Study on the Model Development and Empirical Application for Measuring the Radial and Non-radial Efficiencies of Investment in Domestic Seaports (국내항만투자의 방사.비방사적 효율성 측정을 위한 모형개발 및 실증적 적용에 관한 연구)

  • Park, Ro-Kyung
    • Journal of Korea Port Economic Association
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    • v.27 no.1
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    • pp.185-212
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    • 2011
  • The purpose of this paper is to show the empirical analysis way for measuring the seaport efficiency by using the previous radial model and the newly modified non-radial models( panel additive model, panel RAM model, and panel SBM model)with Spearman rank order correlation coefficient(SROCC) for 20 Korean ports during 11 years(1997-2007) for 1 inputs(port investment amount) and 4 outputs(Number of Ship Calls, Port Revenue, Customer Satisfaction Score for Port Service and Container Cargo Throughput). The main empirical results of this paper are as follows. First, consistency ratio of SROCC in terms of efficiency scores between radial and panel Additive model was over about 76% and overall consistency ratio was about 71.6%. Second, an efficiency of panel RAM model was higher than that of radial model with similarity. However, panel SBM model shows the very similar efficiency scores with panel radial model. Third, the slack size of radial model is smaller compared to non-radial model. Models' ranking orders in terms of efficiency scores, number of efficient ports are panel RAM model, panel SBM model, and radial model. The order from the minimum efficiency scores was the same order like just before. The policy implication to the Korean seaports and planner is that Korean seaports should introduce the new methods like non-radial models(panel additive model, panel RAM model, and panel SBM model) for measuring the port performance.

Verification of Two Dimensional Hydrodynamic Model Using Velocity Data from Aerial Photo Analysis (항공사진분석 자료를 이용한 2차원 하천흐름 해석모형의 검증)

  • Seo, Il Won;Kim, Sung Eun;Minoura, Yasuhisa;Ishikawa, Tadaharu
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.6B
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    • pp.515-522
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    • 2011
  • The hydrodynamic models are widely used in the research for analysis of flow characteristics and design of hydraulic structure and river channel. These models need to be calibrated with observed data. But, there are few field data of two-dimensional flow velocity in flood because the direct measurement of the flood flow velocity are very dangerous. For this reason the results of two-dimensional numerical models are usually calibrated and verified with only a few observed data. Moreover, the verification of numerical models for the design flood is usually carried out using the result of one-dimensional model, HEC-RAS. In this study, using the flow velocity profile extracted from the aerial photos of a flood of the Tone River in Japan, two-dimensional numerical models, RAM2 in RAMS, RMA2 in SMS, and one-dimensional numerical model, HEC-RAS which are most widely used in research and design work are verified and the validity for verification of two-dimensional models with HEC-RAS is reviewed. The results showed that the water surface elevation of HEC-RAS, RAM2 and RMA2 models have similar results with observed data. But, the velocity results of RAM2 and RMA2 models in the floodplain have some difference with the velocity from aerial photo analysis. And the velocity result of HEC-RAS has big difference with the sectional averaged value of velocity from aerial photo analysis.

Reversibility and safety of KISS1 metastasis suppressor gene vaccine in immunocastration of ram lambs

  • Han, Yan-Guo;Liu, Gui-Qiong;Jiang, Xun-Ping;Xiang, Xing-Long;Huang, Yong-Fu;Nie, Bin;Zhao, Jia-Yu;Nabeel, Ijaz;Tesema, Birhanu
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.6
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    • pp.835-841
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    • 2018
  • Objective: The aim of this study was to investigate the reversibility and safety of KISS1 metastasis suppressor (KISS1) gene vaccine in immunocastration. Methods: Six eight-week old ram lambs were randomly divided into vaccinated and control groups. The vaccine (1 mg/ram lamb) was injected at weeks 0, 3, and 6 of the study. Blood samples were collected from the jugular vein before primary immunization and at weeks 2, 4, 6, 10, 14, 22, and 30 after primary immunization. All ram lambs were slaughtered at 38 weeks of age, and samples were collected. Results: The specific anti-KISS1 antibody titers in vaccinated animals were significantly higher and the serum testosterone level was significantly lower than those in the control groups from week 4 to 14 after primary immunization (p<0.05). No significant difference was observed at weeks 22 and 30 after the primary immunization. Similar results were also found for scrotal circumference, testicular weight, length, breadth, and spermatogenesis in seminiferous tubules in week 30 after primary immunization. KS (KISS1-hepatitis B surface antigen S) fusion fragment of KISS1 gene vaccine was not detected in host cell genomic DNA of 9 tissues of the vaccinated ram lambs by polymerase chain reaction. Conclusion: The effects of KISS1 gene vaccine in immunocastration were reversible and no integration events were recorded.

Building TRMS S/W based on Reliability Centered Maintenance (신뢰성 기반의 유지보수를 위한 TRMS S/W개발)

  • Ahn, E.J.;Lee, K.S.;Lee, K.S.;Kim, S.O.;Yoo, D.Y.;Kim, C.H.;Yoon, H.S.;Lee, I.H.;Oh, S.H.
    • Journal of the Korean Society for Railway
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    • v.13 no.2
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    • pp.159-165
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    • 2010
  • In this paper the TRMS (Tilting Rolling-stock Maintenance System) that applies the concept of RAM (Reliability, Availability, and Maintainability) and RCM (Reliability Centered Maintenance) to Preventive and Corrective Maintenance Policy for TTX (Tilting Train Express) will be discussed. We will briefly introduce the RCM concepts and discus show these concepts and procedures are implemented in the TRMS S/W. In the TRMS S/W there are four modules, System and Operations Information Module, FMECA(Failure Modes, Effects, and Criticality Analysis)module, RAM Information Module, and RCM Analysis Module. The System and Operations Information Module provides the user interface for collection of systems and operations related data and the FMECA module provides a groundwork for the RCM analysis. The algorithms to calculate the reliability and failure rate for Weibull distribution and formulae to calculate the task intervals and task costs are proposed in the RAM and RCM Analysis Module respectively. There is a good possibility of applying RCM to other rolling stock maintenance systems if the benefit that RCM can brings to the maintenance world is fully recognized.

TP53 Polymorphisms in Sporadic North Indian Breast Cancer Patients

  • Sharma, Sarika;Sambyal, Vasudha;Guleria, Kamlesh;Manjari, Mridu;Sudan, Meena;Uppal, Manjit Singh;Singh, Neeti Rajan;Bansal, Darpan;Gupta, Arun
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.16
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    • pp.6871-6879
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    • 2014
  • Background: The purpose of this study was to evaluate the potential association of five (p.P47S, p.R72P, PIN3 Ins16bp, p.R213R and r.13494g>a) polymorphisms of TP53 with the risk of developing breast cancer in North Indian Punjabi population. Methods: We screened DNA samples of 200 sporadic breast cancer patients (197 females and 3 males) and 200 unrelated healthy, gender and age matched individuals for the polymorphisms. Results: For the p.P47S polymorphism, we observed the PP genotype in 99.5% of the patients and PS genotype in only 1 patient. All the controls had the wild type PP genotype. The frequency of RR, RP and PP genotype of p.R72P was 23.5% vs 33.5%, 51.5% vs 45.5% and 25% vs 21% in patients and controls respectively. Heterozygous (RP) genotype was increased in breast cancer patients as compared to controls (51.5 vs 45.5%) and showed 1.61 fold significantly increased risk for breast cancer (OR=1.61, 95% CI, 1.01-2.58, p=0.04). In breast cancer patients the frequencies of A1A1, A1A2 and A2A2 genotypes of PIN3 Ins16bp polymorphism were 67%, 26% and 7% respectively whereas in controls the genotype frequencies were 68.5%, 27.5% and 4% respectively, with no significant difference. For p.R213R (c.639A>G), all individuals had homozygous wild type genotype. The frequencies of GG, GA and AA genotypes of TP53 r.13494g>a polymorphism were 62 vs 67.5%, 33 vs 28% and 5 vs 4.5% in patients and controls respectively, again without significant difference. We observed that RP-A1A1 genotype combination of p.R72P and PIN3 Ins16bp and RP-GG combination of p.R72P and r.13494g>a polymorphism showed significant risk of breast cancer (OR=1.65, 95%CI: 0.98-2.78, p=0.05; OR=1.72, 95%CI: 1.01-2.92, p=0.04). Conclusion: The results of present study indicated that among the five TP53 polymorphisms investigated, the p.R72P polymorphism, and the RP-A1A1 and RP-GG genotype combination contribute to breast cancer susceptibility in North Indians.