• Journal of Biomedical Engineering Research
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• v.25 no.6
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• pp.431-438
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• 2004

Medical ultrasonic imaging is a useful imaging facility known to be most safe and easy. It enables physicians to observe the inside structures of the bodies, blood flow, and motions of internal organs. Some physical properties of biologic tissues can also be estimated from backscattered sounds. However, the ultrasonic pulses interrogating the living organisms leave their footprints in the returning signals during imaging. Some significant details are buried in the footprints and their overlaps from adjacent particles. These distortions also decrease the quality of the images. Many research efforts have been made to enhance the image quality and to recover the acoustic information in various ways. In this study, a new interrogation method based on the wavelet and subband filter bank is proposed. It adopts the subband wavelet filters satisfying the perfect-reconstruction (PR) conditions as the interrogating pulses to restore the details useful in tissue characterization and to enhance the image quality. The proposed method was applied to two types of simulations of ultrasonic imaging. The results showed its ability to restore the detailsin the simulated interrogation of biologic tissues, and verified the improved image quality in the simulated imaging of general ultrasonic phantom compared with the conventional method.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.36 no.3
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• pp.75-87
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• 2018

The purpose of this study is to investigate conservation and management methods of the Joseon Royal Tombs under the Eastern District Management Office. Through the literature survey, we understood the process of change of Joseon royal tombs, and through field surveys and interviews, we understood the status of the interior and the surrounding area. In this process, topography, land use and flow of human traffic, architecture and stone objects, water system, historical forests, and facilities were set as the main evaluation indicators. Urbanization has damaged the original terrains of Royal Tombs as national roads, buildings and facilities have constructed in the inner and outer area of Joseon Royal Tombs. Construction of underground passage, land purchase, relocation and demolition of the buildings are required for the conservation of the Royal Tombs area, and then it is necessary to recover the original terrain. In the case of land use and pathways, there are many disconnection of the original ritual circulation, they should be maintained to remind the sacred atmosphere of the royal tomb. And It is necessary to collect accurate information on the lost buildings and stoneworks through literature survey and excavation investigation, and that investigations should be lead to the exposure or restoration of the ruins. Historical forests require periodic and ongoing monitoring and management, and it is necessary to establish new entrance area and appropriate facilities following the long-Term conservation and management plan. These plans should be classified into short, medium and long-Term projects according to urgency and securing financial resources with a long perspective to implement continuous and systematic projects.

• The KIPS Transactions:PartA
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• v.18A no.5
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• pp.193-204
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• 2011

Since web applications are accessed by anonymous users via web, more security risks are imposed on those applications. In particular, because security vulnerabilities caused by insecure source codes cannot be properly handled by the system-level security system such as the intrusion detection system, it is necessary to eliminate such problems in advance. In this paper, to enhance the security of web applications, we develop a static analyzer for detecting the well-known security vulnerability of PHP file inclusion vulnerability. Using a semantic based static analysis, our vulnerability analyzer guarantees the soundness of the vulnerability detection and imposes no runtime overhead, differently from the other approaches such as the penetration test method and the application firewall method. For this end, our analyzer adopts abstract interpretation framework and uses an abstract analysis domain designed for the detection of the target vulnerability in PHP programs. Thus, our analyzer can efficiently analyze complicated data-flow relations in PHP programs caused by extensive usage of string data. The analysis results can be browsed using a JAVA GUI tool and the memory states and variable values at vulnerable program points can also be checked. To show the correctness and practicability of our analyzer, we analyzed the source codes of open PHP applications using the analyzer. Our experimental results show that our analyzer has practical performance in analysis capability and execution time.

• The Korean Journal of Quaternary Research
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• v.25 no.1
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• pp.15-30
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• 2011

Three sediment cores from two different locations (UJ-03 and UJ-12 cores of valley sediment in Paju area, and CL-4 core of wetland sediment in Cheollipo area) along the western Korean Peninsula yield crucial information on the timing and spatial pattern of century-scale climate changes and subsequent surficial responses during the Holocene. In Paju area, the sediments included abundant coarse-grained sediment (coarse sands and pebbles) from 7100 to 5000 cal. yrBP, total organic carbon (TOC) values showed a marked increase from 5000 to 2200 cal. yrBP, several intermittent depositional layers were observed from 2200 cal. yrBP. In Cheollipo area, lake environment developed from 7360 to 5000 cal. yrBP, the deposition of organic materials increased from 5000 to 2600 cal. yrBP, peatland formed from 2600 cal. yrBP. The two patterns of surficial responses to the climate changes through the Holocene are different to each other. This might be due to the dissimilarity in geomorphic conditions. However, the approximate simultaneity of environmental changes in two areas shows that they both can be correlated to the major climate changes. Two areas which have undergone significant changes indicated that the hydrological factors including precipitation and strength of water flow were most responsible for the landscape and geomorphic evolutions. Although the upwards trend in relative sea-level also played a primary role for environmental changes in coastal area (Cheollipo area), detailed studies have still to be undertaken.

• Journal of the Korean association of regional geographers
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• v.4 no.2
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• pp.1-14
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• 1998

This research concerns with the urbanization in Pusan City, the largest port city of Korea focus on the changes of traffic volume from 1970 to 1994. These results are as follow: (1) Urbanization of Pusan City has progressed with increasing the efficiencies of streets. At the first, it's ribbon developed along the main artery toward inland. Urbanization is the process of bear a resemblance to characteristics of CBD. It has both expansion and diffusion processed, simultaneously. Urbanization has progressed centered certain nuclei and developed with more varieties are ally and temporally. (2) Traffic volumes according to times which go and return to piers affected to the traffic pattern of the some parts within the city, it is one of characteristics in port city. Variation of traffic volumes according to times much greater at the nearer streets the piers and connected street with it than the rest of the areas within the city. Rivers and mountains affecting to the traffic pattern and play roles of diffusion barriers for urbanization. (3) In the mid-1980, regions which locate along the main arteries had reached to as same level of urbanization as central part of the city. And higher ranked central places within Pusan City developed toward pattern of CBD in the past. It suggests that these central places revoluted to the recreation of CBD function in the past. (4) Urbanization has developed as same as cell differentiation in process, and it encouraged the more greater variation among the regions and become clear the hierarchy of central places within the city.

• Journal of Satellite, Information and Communications
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• v.6 no.2
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• pp.97-101
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• 2011

Interplanetary space between Sun and Earth is area of flowing very fast solar wind which is contained X ray, flare, corona mass, etc. occurred Sun surface to Earth. This solar wind is affected directly to Earth magnetosphere and ionosphere so that this bring out broadcasting and communication interruptions, satellite operation obstacles and power gird defects and etc..Solar wind flow in interplanetary space is measured as solar wind speed, density and direction by measuring scintillation value to be produced during radio source is passed through solar wind. The wider effective collective areas and the more radio sources, accuracy of solar wind measuring is got higher. Function test was performed using 3 tiles which was manufactured as prototype. Restriction of quantity of tiles, test was performed to confirm whether measured beam pattern is complied with requirement or not. In this paper, it is shown design and their specification of ground interplanetary radio measurement system as well as technical issues and resolutions which were raised during design phase. Also result of function verification test using prototype is suggested. It is confirmed that measured beam pattern was met with requirement.

• Journal of KIISE:Computing Practices and Letters
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• v.10 no.6
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• pp.484-498
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• 2004

In this paper. we propose a novel performance monitoring scheme for heterogeneous SOAP nodes. The scheme is basically based on two-level (kernel-level and user-level) packet filtering of TCP flows. By TCP flow, we mean a sequence of raw packet streams on a TCP transaction. In this scheme, we detect and extract SOAP operations embedded in SOAP messages from TCP flows. Therefore, it becomes possible to monitor heterogeneous SOAP nodes deployed on diverse SOAP-based middlewares such as .Net and Apache AXIS. We present two implementation mechanisms for the proposed scheme. The first mechanism tries to identify SOAP operations by analyzing all fragmented SOAP messages on TCP flows. However, a naive policy would incur untolerable overhead since it needs to copy all packets from kernel to user space. The second mechanism overcomes this problem by selectively copying packets from kernel to user space. For selective copying, we use a kernel-level packet filtering method that makes use of some representative TCP flags.(e.g. SIN, FIN and PSH). In this mechanism, we can detect SOAP operations only from the last fragment of SOAP messages in most cases. Finally, we implement a SOAP monitoring system using a component ca]led SOAP Sniffer that realizes our proposed scheme, and show experimental results. We strongly believe that our system will play a vital role as a tool for various services such as transaction monitoring and load balancing among heterogeneous SOAP nodes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.160-166
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• 2018

The worldwide semi-conductor market has been growing for a long time. Manufacturing lines of semi-conductors need to handle several types of toxic gases. In particular, they need to be controlled accurately in real time. This type of toxic gas control system consists of many different kinds of parts, e.g., fittings, valves, tubes, filters, and regulators. These parts obviously need to be manufactured precisely and be corrosion resistant because they have to control high pressure gases for long periods without any leakage. For this, surface machining and hardening technologies of the metal block and metal gasket need to be studied. This type of study depends on various factors, such as geometric shapes, part materials, surface hardening method, and gas pressures. This paper presents strong concerns on a series of simulation processes regarding the differences between the inlet and outlet pressures considering several different fluid velocity, tube diameters, and V-angles. Indeed, this study will very helpful to determine the important design factors as well as precisely manufacture these parts. The EP (Electrolytic Polishing) process was used to obtain cleaner surfaces, and hardness tests were carried out after the EP process.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.8
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• pp.261-270
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• 2014

As Internet traffic increases recently, much effort has been put on improving the performance of a web server. In addition to hardware side solutions such as replacement by high-end hardware or expansion of the number of servers, there are software side solutions to improve performance. Recent studies on these software side solutions have been actively performed. In this paper, we identify performance degradation problems occurring in a conventional TCP networking reception process and propose a way to solve them. We improve performance by combining three kinds of existing methods for Linux Networking Performance Improvement and two kinds of newly proposed methods in this paper. The three existing methods include 1) an allocation method of a packet flow to a core in a multi-core environment, 2) ITR(Interrupt Throttle Rate) method to control excessive interrupt requests, and 3) sk_buff data structure recycling. The two newly proposed methods are fd data structure recycling and epoll_event data structure recycling. Through experiments in a web server environment, we verify the effect of our two proposed methods and its combination with the three existing methods for performance improvement, respectively. We use three kinds of web servers: a simple web server, Lighttpd generally used in Linux, and Apache. In a simple web server environment, fd data structure recycling and epoll_event data structure recycling bring out performance improvement by about 7 % and 6%, respectively. If they are combined with the three existing methods, performance is improved by up to 40% in total. In a Lighttpd and an Apache web server environment, the combination of five methods brings out performance improvement by up to 36% and 20% in total, respectively.

• The KIPS Transactions:PartD
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• v.11D no.2
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• pp.435-442
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• 2004

It is important to integrate an enterprise application for automating of the business process, which is responded by a flow of market environment. There are two categories of method that integrate enterprise applications. One is Synchronous Integration, and the other is Asynchronous Integration. EAI(Enterprise Application Integration) and Web service which of the asynchronous integration is focused in the automating method of the business process. After we construct the application integration for automating of the business process, we have to concern about managing of the business transaction. Many Organizations have proposed the process method of business transaction based on 2-phase commit protocol. But this method can't supply the phase that classify the transaction by transaction weight. In this paper, we propose an efficient method of transaction process for business transactions, which is composed by "Classify Phase" that classify transactions. We called this model "3-Phase Commit Method Applied by Classify Phase, " we design this model to manage an resource of enterprise efficiently. The proposed method is compared by the method based on 2-Phase commit that could be a problem of management the resource of enterprise, and the advantage of this method is certified to propose the solution of that problem.ion of that problem.