• Journal of Radiation Protection and Research
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• v.36 no.4
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• pp.216-222
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• 2011

Lab effectively supplemented the effects of outside radiation on image plates in the process of image acquisition of CR (computed radiography) systems and conducted for effective utilization in the case of clinical application. For this, Lab classified the storage places and time periods of image plates and compared and analyzed the differences between small dark spots. Lab also assessed the concentration distribution within the boundaries of images. Lab compared and measured the number of dark spots in a light room and a dark room depending on the storage places of image plates and found that dark spots slightly increased in an image plate when stored in a light room on the first and second days. Dark spots increased in proportion to the length of time stored. In the case of the image plate stored in a dark room, the number of dark spots remarkably decreased. With regard to picture quality as related to the location of image plates, the damage to picture quality could be reduced by locating regions of interest in the center. With regard to differences in sharpness following changes in the thickness of subjects, fewer scatter rays occurred and sharpness improved by reducing the thickness of subjects as much as possible. To get medical images of excellent quality, image plates should be managed effectively and it is desirable to keep images plates in dark iron plate boxes and not to expose them to outside radiation for a long time.

• Journal of Digital Convergence
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• v.18 no.3
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• pp.163-169
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• 2020

A smart key has been used in a variety of embedded environments and there also have been attacks from a remote place by amplifying signals at a location of a user. Existing studies on defence techniques suggest multiple sensors and hash functions to improve authentication speed; these, however, increase the electricity usage and the probability of type 1 error. For these reasons, I suggest an embedded security controller based on client authentication and user movement information improving the authentication method between a controller and a host device. I applied encryption algorithm to the suggested model for communication using an Arduino board, GPS, and Bluetooth and performed authentication through path analysis utilizing user movement information for the authentication. I found that the change in usability was nonsignificant when performing actions using the suggested model by evaluating the time to encode and decode. The embedded security controller in the model can be applied to the system of a remote controller for a two-wheeled vehicle or a mobile and stationary host device; in the process of studying, I found that encryption and decryption could take less then 100ms. The later study may deal with protocols to speed up the data communication including encryption and decryption and the path data management.

• Proceedings of the Speleological Society Conference
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• 1994.05a
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• pp.106-110
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• 1994

$\bigcirc$ 동굴생물은 식물과 동물, 미생물로 크게 구분되지만 태양광선이 완전히 차단된 동굴내 환경에서는 동굴 동물들이 주종을 이루고 있다. $\bigcirc$ 동굴내의 동물에 관한 연구는 1966년 고씨동굴, 용담굴을 시발로 고수굴, 천동굴, 노동굴, 백룡굴, 대이굴, 환선굴 등 강원도내에 분포하는 동굴 중 약 30%정도는 동물을 포함한 생물상이 조사되었다. $\bigcirc$ 강원도의 동굴동물로서 확인된 것온 9종 30목141종이며 강별로는 곤충강이 9목 50종 주형강이 4목 49종 갑각강이 6목 18종의 순으로 우세하고 목별로는 거미목이 15과 39종, 톡토기목이 7과 20종, 딱정벌레목이 8과 15종으로 우세한 편이다 (남, 1987). $\bigcirc$ 동굴생물에 관한 연구는 육상생태계와 격리된 환경에서 생리, 생태적 적응을 통한 종의 분화나 유전, 진화문제를 추구하며 지하생태계와 육상생태계의 생물적인 유연관계 규명에 중요한 분야로 인정되며 아울러 독특한 특성을 지닌 동굴생물의 보존을 위한 방안과 노력이 일부동굴의 개방 및 개발에 앞서 더욱 구체적으로 모색되고 증대되어야 한다. $\bigcirc$ 동굴환경의 주요 특성은 첫째 햇빛이 차단되어 암흑상태이며, 둘째 내부습도가 높고 기온이나 수온의 연중변화가 심하지 않고, 셋째 먹이연쇄에 필수적인 영양공급원이 제한되어 있다. 따라서 광합성작용으로 성장하는 녹색식물은 태양광선이 유입되는 곳이나 인공조명시설 지역을 제외한 곳에서는 서식이 불가능하고 대형동물이나 초식동물은 생존이 어렵다. $\bigcirc$ 동굴내에는 환경에 적응하는 종들만이 서식할 수 있고 이들을 생태적 특성에 따라 세가지로 구분 할 수 있다. 환경적응 요인으로는 광도, 습도, 온도 영양공급원과 섭식장소, 수중생물의 경우는 특히 수온, 수량 영양원등이다.(중략)다. 본 연구의 접근방법으로는 ASRS의 개념적인 Reference Model을 수립하고 이 Reference Model에 대한 Formal Model로 DEVS(Discrete Event System Specification)을 이용하여 시스템을 Modeling하였다. 이의 Computer Simulation을 위하여 DEVS형식론 환경에서의 Simulation Language인 DEVSim ++ⓒ를 이용하여 시스템을 구현하였다.. 실형 결과로는 먼저 선형 상미분방정식의 예로 mass-damper-spring system, 비선형 상미분방정식의 예로는 van der Pol 방정식, 연립 상미분방정식의 예로는 mixing tank problem 등을 보였으며, 그의 공학에서 일어나는 여러 가지 문제들도 다루었다.화물에 대한 방어력이 증가되어 나타난 결과로 여겨지며, 또한 혈청중의 ALT, ALP 및 LDH활성을 유의성있게 감소시키므로서 감잎 phenolic compounds가 에탄올에 의한 간세포 손상에 대한 해독 및 보호작용이 있는 것으로 사료된다.반적으로 홍삼 제조시 내공의 발생은 제조공정에서 나타나는 경우가 많으며, 내백의 경우는 홍삼으로 가공되면서 발생하는 경우가 있고, 인삼이 성장될 때 부분적인 영양상태의 불충분이나 기후 등에 따른 영향을 받을 수 있기 때문에 앞으로 이에 대한 많은 연구가 이루어져야할 것으로 판단된다.태에도 불구하고 [-wh]의미의 겹의문사는 병렬적 관계의 합성어가 아니라 내부구조를 지니지 않은 단순한 단어(minimal $X^{0}$ elements)로 가정한다. 즉, [+wh] 의미의 겹의문사는 동일한 구성요 소를 지닌 병렬적 합성어([$[W1]_{XO-}$ $[W1]_{XO}$ ]$_{XO}$)로 그리고 [-wh] 의미의 겹의문사는 중복된 발은을 지닌 한 단어로 ([W]$_{XO}$

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.4
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• pp.457-467
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• 2002

In order to simulate cyber attacks and predict network behavior by attacks, we should represent attributes of network components in the simulation model, and should express characteristics of systems that carry out various cyber attacks and defend from these attacks. To simulate how network load may change under the cyber attacks, we extended SSF[9, 10] that is process-based event-oriented simulation system. We added a firewall class and a packet manipulator into the SSFNet that is a component of SSF. The firewall class, which is related to the security, is to simulate cyber attacks, and the packet manipulator is a set of functions to write attack programs for the simulation. The extended SSFNet enables to simulate a network with the security systems and provides advantages that make easy to port already exsiting attack programs and apply them to the simulation evironment. We made a vitual network model to verify operations of the added classes, and simulated a smurf attack that is a representative denial of sevive attack, and observed the network behavior under the smurf attack. The results showed that the firewall class and packet manipulator developed in this paper worked normaly.

• 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 Journal of the Korea Contents Association
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• v.8 no.2
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• pp.182-194
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• 2008

Corporate managers look at IT outsourcing as long-term strategic choices not as short-term tactical ones, and maximizing the effect that IT outsourcing brings about is the main concern to them. Emerging different types of IT outsourcing and their effects on the corporate business decisions necessitate the research on this subject. According to previous researches, the Intent for IT outsourcing is categorized as IS Improvement, Business Impact, and Commercial Exploitation. The decison factors for these IT outsourcing include corporate strategy types, IT role, and interaction between these two. Firm size and IT maturity are selected as moderating factors to add the credibility to the research of the effect of IT outsourcing decision making. Analyzing collected data revealed that corporate strategy rather than IT role is more significant factor affecting the intent for IT outsourcing decision. Defenders(as in corporate strategy types) tend to use IT outsourcing more as a means to improve information systems, compared to analyzers and reactors. Prospectors tend to use IT outsourcing more as a commercial exploitation, compared to analyzers and reactors. These outcomes prove that corporate strategy characteristics reflect outsourcing intent. There were previous researches that showed outsourcing decision depends on IT role, however the hypothesis was rejected that IT role determines outsourcing intent. It was also rejected that the interaction between corporate strategy types and IT role determines outsourcing intent. Corporate decision makers should first analyze corporate strategy, and reflect it on the outsourcing intent when they make IT outsourcing decisions. Only the precise defining of IT outsourcing intent will lower the risk and increase the possibility of success.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.8
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• pp.432-444
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• 2004

In this paper, we construct the TMO-based object group model on distributed environment, and analyze and evaluate the executability for distributed real-time service of our object group model by developing the distributed real-time application simulator applying the model. The Time-triggered Message-triggered Object(TMO) is a real-time server object having real-time property itself. The TMO-based object group is defined as a set of objects which logically reconfigured the physically distributed one or more TMOs on network by a given distributed application. For supporting group management of the server objects, the TMO-based object group we suggested provides the functions which register and withdraw the solver objects as a group member to an arbitrary object group, and also provides the functions which insert and delete the access rights of server objects from clients. Also, our model was designed and implemented to support the appropriate object selection and dynamic binding service for a single TMO as well as the duplicated TMOs, and to support the real-time scheduling service for the clients which are requesting the service. Finally, we developed the Defence System against Invading Enemy Planes(DSIEP) simulator as a practical example of distributed real-time application by applying our model, and evaluated the adaptability of distributed service strategies for the group components and the executability of real-time services that the TMO-based object group model provides.

• Journal of radiological science and technology
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• v.28 no.1
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• pp.55-65
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• 2005

Research of actual condition of working conditions in the small and clinics, in the Seoul metropolitan city and Kyeonggido province. With the health care environmental change such as a rapid increase of the elderly people, rapid increase of health promotion needs, it is necessary to analyse and identity of the actual condition of working conditions for present and new radiological technologist. Research of general characteristics for the present radiological technologist. To research of the status employment, business scope, pay, working conditions, radiation safety management, equipment, and category association. Defining the problems of related working conditions, radiation safety management for the comprehensive methods to promote the rights the radiological technologist. A proposal for establishment legislature and system of the actual condition in the hospital for radiological technologist. Estimation for the demand and supply numbers of present radiological technologist and improvement of employment relations. Improved and refined scope business and duty regulation related to radiological technologist. Application for the establishment and development of promotion rights to utilize as basic data in a legislative and system frame of reference to implement the radiological technologist.

• Proceedings of the SCSK Conference
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• 1996.07a
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• pp.33-51
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• 1996

화장품의 변질요인은 크게 물리적 또는 화학적 변화에 의한 요인과 미생물오염으로 인한 각종 문제점으로 대별될 수 있다. 이 중에서 미생물 오염문제는 제품의 상품가치에 미치는 영향 뿐만 아니라 지속적인 사용에 의한 피부의 위생적 측면때문에 그 중요성에 대한 인식이 높아지고 있다. 따라서, 제품개발시는 화장품 처방중의 영양성분의 배합, pH, 유화형태, 방부제의 혼합, 분배계수 및 그 안정성을 고려하여야 함은 물론이고 처방중의 모든 원료의 각각에 대한 항균능 및 피부자극여부를 사전에 미리 조사하여 각 제품별로 적당한 방부체계를 선택하는 것은 매우 중요한일이다. 독성실험방법에 있어서 in vivo 실험에 대체할 수 있는 새로운 in vitro 실험방법 수립 즉, 동물실험을 하지 않고 in vitro 실험결과로부터 in vivo 결과를 예측할 수 있도록 새로운 in vitro 실험체계의 가능성을 실험하였다. 4종의 cell line중 transformed mouse fibroblast L929가 본 실험에서 사용하기에 배양상의 용이성과 안정성, 재현성의 관점에서 가장 알맞은 cell line이었다. transformed mouse fibroblast L929를 사용한 NR$_{50}$ assay와 Draize score간의 regression coefficient ${\gamma}$값은 0.91이었다. 혈청은 시험물질의 세포에 대한 민감성에 영향을 주었다. 따라서, modified serum-free method를 이용함으로써 regression coefficient가 증가된 즉, 상관성 및 재현성이 높은 결과를 얻을 수 있었다. 이러한 기술은 독성실험에 실험동물을 사용하지 않고 in vivo test에 대체 할 수 있고, 또한 화학물질에 대한 prescreening으로 이용할 수 있을 것으로 판단된다.원과 섭식장소, 수중생물의 경우는 특히 수온, 수량 영양원등이다.(중략). 본 연구의 접근방법으로는 ASRS의 개념적인 Reference Model을 수립하고 이 Reference Model에 대한 Formal Model로 DEVS(Discrete Event System Specification)을 이용하여 시스템을 Modeling하였다. 이의 Computer Simulation을 위하여 DEVS형식론 환경에서의 Simulation Language인 DEVSim ++ⓒ를 이용하여 시스템을 구현하였다.. 실형 결과로는 먼저 선형 상미분방정식의 예로 mass-damper-spring system, 비선형 상미분방정식의 예로는 van der Pol 방정식, 연립 상미분방정식의 예로는 mixing tank problem 등을 보였으며, 그의 공학에서 일어나는 여러 가지 문제들도 다루었다.화물에 대한 방어력이 증가되어 나타난 결과로 여겨지며, 또한 혈청중의 ALT, ALP 및 LDH활성을 유의성있게 감소시키므로서 감잎 phenolic compounds가 에탄올에 의한 간세포 손상에 대한 해독 및 보호작용이 있는 것으로 사료된다.반적으로 홍삼 제조시 내공의 발생은 제조공정에서 나타나는 경우가 많으며, 내백의 경우는 홍삼으로 가공되면서 발생하는 경우가 있고, 인삼이 성장될 때 부분적인 영양상태의 불충분이나 기후 등에 따른 영향을 받을 수 있기 때문에 앞으로 이에 대한 많은 연구가 이루어져야할 것으로 판단된다.태에도 불구하고 [-wh]의미의 겹의문사는 병렬적 관계의 합성어가 아니라 내부구조를 지니지 않은 단순한 단어(minimal $X^{0}$ elements)로 가정한다. 즉, [+wh] 의미의 겹의문사는 동일한 구성요 소를 지닌 병렬적 합성어([$[W1]_{XO-}$ $[W1]_{XO}$ ]

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.4
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• pp.28-36
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• 2021

It is known that buried rebars inside concrete structures are protected from corrosion due to passive layer. It is very important to delay the timing of corrosion or evaluate a detection of corrosion initiation for the purpose of cost-beneficiary service life of a structure. In this study, corrosion monitoring was performed on concrete specimens considering 3 levels of cover depth(60 mm, 45 mm, and 30 mm), W/C(water to cement) ratio(40.0%, 50.0%, and 60.0%) and chloride concentration(0.0%, 3.5%, and 7.0%). OCP(Open Circuit Potential) was measured using agar-based socket type sensors. The OCP measurement showed the consistent behavior where the potential was reduced in wet conditions and it was partially recovered in dry conditions. In the case of 30 mm of cover depth for most W/C ratio cases, the lowest OCP value was measured and rapid OCP recovery was evaluated in increasing cover depth from 30 mm to 45 mm, since cover depth was an effective protection against chloride ion ingress. As the chloride concentration increased, the effect on the cover depth tended to be more dominant than the that of W/C ratio. After additional monitoring and physical evaluation of chloride concentration after specimen dismantling, the proposed system can be improved with increasing reliability of the corrosion monitoring.