• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.6
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• pp.1157-1169
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• 2021

The disaster recovery refers to policies and procedures to ensure continuity of services and minimize loss of resources and finances in case of emergency situations such as natural disasters. In particular, the disaster recovery method by the cloud service provider has advantages such as management flexibility, high availability, and cost effectiveness. However, this method has a dependency on a service provider and has a structural limitation in which a user cannot be involved in personal data. In this paper, we propose a protocol using proxy re-encryption for data confidentiality by removing dependency on service providers by backing up user data using blockchain and distributed storage. The proposed method is implemented in Ethereum and IPFS environments, and presents the performance and cost required for backup and recovery operations.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.5
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• pp.915-923
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• 2023

As environmental regulations on carbon emissions are strengthened worldwide, the existing internal combustion engine-centered automobile industry is being reformed. In particular, large buses and large cargo trucks are pointed out as one of the main causes of environmental destruction due to excessive carbon emissions. The E-Highway power collection system, which has recently been proposed as a solution, uses the vehicle's battery as a backup power source or regenerative braking, depending on whether the pan head of the pentograph installed in the vehicle is in contact with the overhead line. It is used to store the excess energy generated. However, wear through contact due to continuous contact reduces the current collection effect and causes failure. In this paper, by using the current difference, the horizontal position information of the panhead in contact with the overhead line is acquired, thereby reducing the abrasion of the conductor and the panhead Make it possible to follow the overhead line. The position estimation method proposed in this paper simply configures a device that can detect the position of the overhead line of the pantograph by the difference in resistance. It is economical and has the advantage of reducing the volume. The characteristics of the pantograph estimating the location of overhead lines were analyzed using the difference between the two currents of the current collector, the feasibility of the positioning estimation system was verified through simulations and experiments.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.4
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• pp.117-123
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• 2013

In the recent cloud storage environment, the amount of SSD (Solid-State Drive) replacing with the traditional hard disk drive is increasing. Management of SSD for its space efficiency has become important since SSD provides fast IO performance due to no mechanical movement whereas it has wearable characteristics and does not provide in place update. In order to manage space efficiency of SSD, data de-duplication technique is frequently used. However, this technique occurs much overhead because it consists of data chunking, hasing and hash matching operations. In this paper, we propose new data de-duplication method using PRAM cache. The proposed method uses hierarchical hash tables and LRU(Least Recently Used) for data replacement in PRAM. First hash table in DRAM is used to store hash values of data cached in the PRAM and second hash table in PRAM is used to store hash values of data in SSD storage. The method also enhance data reliability against power failure by maintaining backup of first hash table into PRAM. Experimental results show that average writing frequency and operation time of the proposed method are 44.2% and 38.8% less than those of existing data de-depulication method, respectively, when three workloads are used.

• Journal of the Society of Disaster Information
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• v.16 no.2
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• pp.392-401
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• 2020

Purpose: This study analyzes the operating characteristics of a lithium ion capacitor that can be used as a standby power supply in an emergency, and determines whether the standby power supply is abnormal even by measuring the voltage using a linear proportionality characteristic during charging and discharging. The aim is to provide an experimental basis that can be done. Method: As a method for this study, first, analyze the operation principle and characteristics of the existing backup power supply and lithium ion capacitor, and then measure the voltage of the lithium ion capacitor according to the configuration and system block diagram of the induction lamp used in the experiment. We proceed with the test of the measured value of discharge power for each voltage band to check the amount of power held by the battery and the operation test experiment using induction lamps. Results: Just by checking the charging voltage using the linear proportional characteristics of lithium ion capacitors, it provides a basis for accurately inferring the effective operating time of induction lamp lamps. Conclusion: In the event of a disaster, the lithium ion capacitor is used as a spare power supply for emergency induction lamps to prevent complete discharge of emergency induction lamps, to prevent the problem of performing normal operation of the standby power supply, and to use only a simple voltage measurement to reserve power. It was intended to suggest many uses for evacuation equipment application in the future by making it possible to check whether the device is abnormal.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.2
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• pp.207-212
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• 2010

Protein C deficiency increases the risk of thrombosis due to the lack of anticoagulant factor protein C. Among the numerous congenital protein C deficiencies, homozygous protein C deficiency has an especially low protein C activity level, that it is almost undetectable. It is a rare disease with a probability of 1:250000~500000. The signs and symptoms of homozygous protein C deficiency include purpuric, necrotic dermatosis, ecchymosis, blindness, and thrombosis in central nervous system. A 4-year-old girl was brought to the clinic with a chief complaint of extensive caries. The child was under warfarin medication in order to prevent possible complications during dental treatment. We consulted the pediatric department. Without warfarin intake, serious complications may occur due to thrombosis during dental treatment. Therefore, certain warfarin dosage (INR 3~5) and fresh frozen plasma as a backup for excessive hemorrhage were recommended. This child was a severely disabled child with the loss of vision, and it was difficult to manage her behavior effectively. Thus, dental treatment was carried out under general anesthesia, where bleeding control would be also easier to achieve.This report presents the case of a 4-year-old girl with protein C deficiency, who has received dental treatment for extensive caries under general anesthesia.

• The Korean Journal of Air & Space Law and Policy
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• v.32 no.1
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• pp.139-175
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• 2017

The Assembly plenary session on December 3, 2017 passed a Product Liability Amendment bill that introduced clauses concerning consumer burden of proof and punitive damage reimbursement. More specifically, these newly approved provisions will reduce the burden of proof placed on consumers and levy triple punitive damage on suppliers. Significant increases in the number of product-liability lawsuit and the number of related insurance contracts are expected. Since military aircraft are designed for operational purpose(seeking greater combat effectiveness over greater safety) and used in high-risk environment, it is practically impossible to obtain an affordable product-liability insurance, Without having any backup plan, military aircraft manufacturers directly face all sort of liability risks under Product Liability Act, Warrant Liability Act and Non-Performance of Contract Act. The U.S. experienced similar problems when they first implemented their product-liability law in 1970s. There had been a big dispute among legal practitioner, insurance professionals and scholars concerning military aircraft manufacturer's liability. In order to settle the issue, the U.S. Supreme Court has established a new precedent of Government Contractor Defense(GCD). The U.S. government also included an indemnity clause for military aircraft manufacturers in their FMS Contract with the Korean government. Likewise, Korean military aircraft manufacturers should 1) clearly understand their current position that they cannot afford expensive product-liability insurance and the cost is not accounted in the military procurement calculation, 2) estimate potential liability risks with the ongoing overseas export expansion in mind, 3) set up appropriate risk management measures through regulatory reform and policy development.

• Journal of Navigation and Port Research
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• v.40 no.6
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• pp.385-390
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• 2016

ELoran Systems can provide Position, Navigation, and Time services with comparable performance to Global Positioning Systems (GPS) as a back up or alternative system. High timing and navigation performance can be achieved by eLoran signals because eLoran receivers use "all-in-view" reception. This incorporates Time of Arrival (TOA) signals from all stations in the service range because each eLoran station is synchronized to Coordinated Universal Time (UTC). Transmission station information and the differential Loran correction data are transmitted via an additional Loran Data Channel (LDC) on the transmitted eLoran signal such that eLoran provides improved Position Navigation and Timing (PNT) over legacy Loran. In this paper, we propose a technique for adapting the delay time compensation values in eLoran timing receivers to provide precise time comparison. For this purpose, we have designed a system that measures time delay from the crossing point of the third cycle extracted from the current transformer at the end point of the transmitter. The receiver delay was measured by connecting an active H-field, an E-field and a passive loop antenna to a commercial eLoran timing receiver. The common-view time transfer technique using the calibrated eLoran timing receiver improved the eLoran transfer time. A eLoran timing receiver calibrated by this method can be utilized in the field for precise time comparison as a GNSS backup.

• Journal of the Korean Operations Research and Management Science Society
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• v.38 no.1
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• pp.15-27
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• 2013

Because consumers tend to have negative opinion about a company that neglects social issues like poverty or pollution while it focuses on its own profit, a lot of companies have invested their resources in Corporate Social Responsibility(CSR). CSR has merits of image improving and profit gaining, on the other hand, it has also many shortcomings. First, the cost of CSR may become a heavy financial burden. Specifically, CSR tends to be implemented by a company's unilateral backup, and then this may impose a heavy burden on the company. Second, one cannot expect effects of CSR in a short-term. Because of these shortcomings, the unilateral CSR has gone into alteration of the type of CSR since 1980's. Instead of unilaterality, Cause-Related Marketing(CRM) began to be used for mutual profits among company, consumers, and society. That is, CRM has become to be spotlighted as a new type of CSR. It focuses on partnership between a company and consumers based on cause and mutual profit pursuing through this partnership. So, many contemporary companies prefer CRM activities that derive their positive corporate image, that increase their sales, and that reduce their financial cost. The IBM Matching Grants Program, which is the largest of the IBM-Employee partnership programs, is a typical CRM. This program enables employees and retirees to increase the value of their donations to educational institutions, hospitals, hospices, nursing homes, and cultural & environmental organizations with a matching gift from IBM. Hundreds of educational institutions and thousands of nonprofit organizations have benefited from the contributions by IBM. There might be various types of matching grants. For example, an employee might choose a lump-sum expense or partitioning a lump-sum into a series of small ongoing expenses for his (or her) donation, and a firm might match the employee's total contribution with a lump-sum expense or might match the employee's total contribution with a series of small ongoing expenses. However, it is not easy to find an academic research on which type of matching grant is preferred by employees. This paper shows that an employee prefers the type of matching grants that consists of a lump-sum expense for his (or her) contribution and a series of small ongoing expenses for a firm's contribution [or the type of matching grants that consists of a series of small ongoing expenses for an employee's contribution and a lump-sum expense for a firm's contribution] to the other types of matching grants.

• Journal of Korean Physical Therapy Science
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• v.4 no.2
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• pp.405-419
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• 1997

This research has been conducted to provide the spinal cord injured patients with comprehensive necessity of and backup data for their rehabilitation in the community and make the aware of importance of overall community support to patients. The data was collected through questionnaire made to 83 patients charged to general hospital in Jeonbuk Province between 1 and 31 March 1997 to analyse the patients ability on activities of daily living through the research on general characteristics and Modified Barthel Index(MBI). As a result the outcome of the research was as follows : 1. Sexual distribution represented that 57 male (68.7%) and 26 female(31.3%) and in the age distribution majority group was 36 thirties (43.4 %) most active in social activities. 2. Analysis on occupation of patients showed majority group was in technicians, 21 people representing 25.4 % and the major cause of injury was traffic accident, 45people representing 54.2%, fall down, 17 people representing 20.5% and industrial accident, 13 people representing 15.7%, respectively. 3. In the multiple choice questionnaire on complications, the rate of appealing pain was highest and spasticity, pressure sore, contracture, depression which restrict the patients from activities of daily living ability were also appeared. 4. The theoretical points in MBI Should lie between 1 and 115 and the average point be 58 but the average point of the MBI among 83 patients was 63. 5. The MBI point by the level of injured represented statistically critical difference(P<0.001) and the MBI points tested by Duncan's Multiple Area Testing in lumbar(80.1) and in thoracic (65.8) represented critically higher than the one in cervical(42.5). 6. In the distribution of the method of Urination after spine injury, the intermittent catheterization represented highest numbar of 34(41.1 %). Testing by Duncan's Multiple Area Testing, as we found the critical difference in the analysis on MBI points(P<0.001), the point in independent self voiding patients ($90.87{\pm}29.34$) was higher than the one in other self voiding patients(P<0.05). 7. In th category of social activities after spine injury, the number of people classified in others, 41 people representing 49.5% was highest and in the MBI points of the spinal cord injured people in religious activity, hobby activity, private club, occupation was critically higher than the people classified in miscellancous(P<0.01) who are the spinal cord injured people and mostly depend on their family's assistance at home in their daily activities.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.7B
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• pp.605-619
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• 2003

The main memory DBMS(MMDBMS) efficiently supports various database applications that require high performance since it employs main memory rather than disk as a primary storage. In this paper, we discuss the index manager of the Tachyon, a next-generation MMDBMS. Recently, the gap between the CPU processing and main memory access times is becoming much wider due to rapid advance of CPU technology. By devising data structures and algorithms that utilize the behavior of the cache in CPU, we are able to enhance the overall performance of MMDBMSs considerably. In this paper, we address the practical implementation issues and our solutions for them obtained in developing the cache-conscious index manager of the Tachyon. The main issues touched are (1) consideration of the cache behavior, (2) compact representation of the index entry and the index node, (3) support of variable-length keys, (4) support of multiple-attribute keys, (5) support of duplicated keys, (6) definition of the system catalog for indexes, (7) definition of external APIs, (8) concurrency control, and (9) backup and recovery. We also show the effectiveness of our approach through extensive experiments.