• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2002.11a
• /
• pp.156-160
• /
• 2002

In this paper, we have estimated by means of the theoretical analysis and the simulation of FCA(Fixed Channel Assignment) and CB(Channel Borrowing) in order to consider the CB as a technique to meet ducting interference from adjacent countries. Also, we assumed that the receiving power level of ducting interference with time rate can be characterized by the normal distribution due to the previous measured results, and the ducting interferences which are exceeding the reference power level can be regarded as calls. These calls can be processed by CR assignment and by which sharing channels between cells brings to us the method of meeting the ducting interference to use spectrum resources effectively. However, the spectrum frequency reusing and the interference effects between channels should be considered in CB simulation in the future.

• The KIPS Transactions:PartA
• /
• v.9A no.1
• /
• pp.37-44
• /
• 2002

Most researches of transforming sequential programs into parallel programs have been based on the loop structure transformation method. However, most programs have implicit interprocedure parallelism. This paper suggests a way of extracting parallelism from the loops with procedure calls using the data dependency elimination method. Most parallelization of the loop with procedure calls have been conducted for extracting parallelism from the uniform code. In this paper, we propose interprocedural transformation, which can be apply to both uniform and nonuniform code. We show the examples of uniform, nonuniform, and complex code parallelization. We then evaluated the performance of the various transformation methods using the CRAY-T3E system. The comparison results show that the proposed algorithm out-performs other conventional methods.

• Electronics and Telecommunications Trends
• /
• v.38 no.3
• /
• pp.57-65
• /
• 2023

Emergency numbers, such as 112 and 119, are used in many countries to connect people in need with emergency services such as police, fire, and medical assistance. We describe development directions of intelligent response technology for emergency calls. The development of this technology refers to enhancing the efficiency and effectiveness of response systems by using advanced methods such as artificial intelligence, machine learning, and big data analytics. We focus on a system that assists the receptionist of an emergency call. In the future, the recognition rate and decision-making accuracy of intelligent response technologies should be improved considering characteristics of public safety and emergency domain data. Although the current technology remains at the level of assisting a receptionist, a fully autonomous response technology is expected to emerge in the future.

• Journal of the Korea Safety Management & Science
• /
• v.10 no.1
• /
• pp.215-224
• /
• 2008

Recently, product life-cycles are shortening faster than ever before, and companies with a suggestion system are in better position to overcome this shortening life-cycle and thus promote customer satisfaction. Suggestion systems, however, are not actively utilized on the production floors in many firms. This study showed that small-sized and medium-sized firms where a suggestion system is properly functioning by a strong will of top management are not many in Gangwon-do area. In considerable number of companies, a suggestion system is informally and spontaneously applied by the workers on the production floors not by company-wide systems. A suggestion system is required as a means of creating future value-added and it is a matter of course that the role of top management, together with middle-class managements' influence is quite important in the course of the successful application of it. A suggestion system, to be successful, calls not only individual efforts but also positive corporate cultures.

• International Journal of Railway
• /
• v.1 no.3
• /
• pp.117-121
• /
• 2008

The personal rapid transit (PRT) system is a small scale transportation system that employs a novel concept to solve the traffic congestion problem in the city area. The PRT system is a driverless on-demand system that a passenger calls a vehicle rather than waits for the vehicle. Therefore, one of the most important issues in the PRT system is how to control the vehicle with the satisfaction of the basic concept of the PRT system. In this paper a computer simulator is introduced to evaluate the vehicle. operational control algorithm of the PRT system. The. computer simulator has the commercial embedded processor boards that operate in the real time operating system and pre-designed vehicle control algorithm is coded into the processor boards. The experimental results present the effectiveness of the proposed evaluation apparatus.

• Fire Science and Engineering
• /
• v.20 no.3 s.63
• /
• pp.42-47
• /
• 2006

Direct medical control by medical doctors is an essential part of emergency medical services system (EMSS). However, the indications are not specifically defined, even in 119 system with their own medical control team. The Seoul Metropolitan Fire and Disaster Management Department has operated internal medical consultation services on its own since January 2004. Based on the experiences from these services, we reviewed the cases of the direct medical consultation and establish the indications for direct medical control. And we presumed the demand of direct medical control with the established indications. The crews of 119 in Seoul made 793 calls to Medical Control Team during November 2004. We reviewed all of the calls according to the level of consciousness (AVPU), the kinds of emergency care done by crews during transport (10 categories), and the mechanisms of injuries (9 categories). The need for direct medical control was judged by authors with reviewing the records reported by the crews and control teams. Among 23 items, 14 items assigned as the indications, which were abnormal level of consciousness (VPU), 6 kinds of emergency care, and 5 mechanisms of injures. The sum of the three of them, 7,782 cases (45.9%), was in need of direct medical control. In conclusion, about half of the patients transported by 119 crews in Seoul require direct medical control. The need for the direct medical control in Seoul was estimated as many as 260 calls per day. To fulfill the need for direct medical control and to provide a effective medical control, the direct medical control should be accomplished through the communications between the crews and the medical staffs in the local hospitals.

• The Journal of the Korea Contents Association
• /
• v.19 no.5
• /
• pp.187-193
• /
• 2019

Key-value storage engines are an essential component of growing demand in many computing environments, including social networks, online e-commerce, and cloud services. Recent key-value storage engines offer many features such as transaction, versioning, and replication. In a key-value storage engine, transaction processing provides atomicity through Write-Ahead-Logging (WAL), and a synchronous commit method for transaction processing flushes log data before the transaction completes. According to our observation, flushing log data to persistent storage is a performance bottleneck for key-value storage engines due to the significant overhead of fsync() calls despite the various optimizations of existing systems. In this article, we propose a group synchronization method to improve the performance of the key-value storage engine. We also design and implement a transaction scheduling method to perform other transactions while the system processes fsync() calls. The proposed method is an efficient way to reduce the number of frequent fsync() calls in the synchronous commit while supporting the same level of transaction provided by the existing system. We implement our scheme on the WiredTiger storage engine and our experimental results show that the proposed system improves the performance of key-value workloads over existing systems.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2006.11a
• /
• pp.618-629
• /
• 2006

This Paper is about optimizing preventive maintenance period of connected (r,s) out of(m,n) : F lattice system that one of multi-component system, (m,n) matrix failure of whole system is occurrence when parts that belong in (r,s) matrix part procession of parts arranged with procession are breakdown all. The preventive maintenance about system is very important viewing from system reliability and operational expense viewpoint. Preventive maintenance that misses a time calls big loss by system failure and expense of frequent full equipment is paid excessively in preventive maintenance itself but expense is paid much in preventive maintenance itself and whole expense escalation can be achieved preferably. Through this research, reliability model is constructed that do expense by smallest under full equipment policy chosen through comparison of each full equipment policy and preventive maintenance expense full equipment cycle and r ,s value are made using simulated annealing algorithm and simulated annealing algorithm that converge fast in multi-component system certified most suitable to optimization decision

• Journal of the Korean Professional Engineers Association
• /
• v.23 no.1
• /
• pp.49-63
• /
• 1990

A signalling system generally designates electrical conditions and transmissionㆍreceiving programs of exchange control use signals concerning the establishmentㆍreleaseㆍtariff etc of calls between telephone subscribers and an exchange office or inter-exchange offices. In signalling system, different systems are being used according as communication service for control. With the development of exchange and transmission technique and higher functional advance, there exist many kinds of signalling systems. As for the signalling system used in international communication, an international standardization is specially important for the exchange of each country to operate properly and execute a smooth exchange connection. A term "signalling system" is chiefly used in telephone exchange system, while in telex exchange system "signalling condition, " and in data exchange system "protocol" is used. "protocol" is used.; is used.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.27 no.4
• /
• pp.803-810
• /
• 2017

Recently, social security problems have been caused by the development of the software industry, and a variety of automation techniques have been used to verify software stability. In this paper, we propose a method of automatically detecting a use-after-free vulnerability on Windows system calls using dynamic symbolic execution, one of the software testing methods. First, a static analysis based pattern search is performed to select a target point. Based on the detected pattern points, we apply an induced path search technique that blocks branching to areas outside of interest. Through this, we overcome limitations of existing dynamic symbolic performance technology and verify whether vulnerability exists at actual target point. As a result of applying the proposed method to the Windows system call, it is confirmed that the use-after-free vulnerability, which had previously to be manually analyzed, can be detected by the proposed automation technique.