• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.3
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• pp.521-530
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• 2017

In this paper, we propose a protection solution against intelligent Ransomware attacks by encrypting not only source files but also backup files of external storage. The system is designed to automatically back up to the cloud server at the time of file creation to perform monitoring and blocking in case a specific process affects the original file. When client creates or saves a file, both process identifiers, parent process identifiers, and executable file hash values are compared and protected by the whitelist. The file format that is changed by another process is monitored and blocked to prevent from suspicious behavior. By applying the system proposed in this paper, it is possible to protect against damage caused by the modification or deletion of files by Ransomware.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.06a
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• pp.153-154
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• 2013

In this study, we used the program of three-dimensional analysis of fire for analyzing visibility of smoke flow and temperature of the accommodation area what is required for the analysis of survival of the crew. In particular, I would like to propose a method for reducing the flow rate performance in order to reduce the suffocation from the smoke of the majority of personal injury. Existing vessels are designed to close the fire door automatically when the fire alarm issued. When there is no crew that dared to escape, it can delay the spread of fire and smoke flow which is determined to be very useful to improve the survival rate of the crew. However, it can be fatal to the crew whose rooms are located on the inside of the fire door that has not completed the evacuation. In this study, we check the smoke flow rate and rate of temperature rise when crew open the fire door what is closed due to fire and compare to the structure of the blocking layer.

• Convergence Security Journal
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• v.18 no.5_1
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• pp.53-58
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• 2018

MANET transmits data by hop-by-hop method because it is composed of mobile nodes without support of any infrastructure. Its structure is very similar to a block chain. However, it is exposed to various threats such as data tampering or destruction by malicious nodes because of transmission method. So, ensuring the integrity of transmitted data is an important complement to MANET. In this paper, we propose a method to apply the block chain technique in order to protect the reliability value of the nodes consisting the network from malicious nodes. For this, hierarchical structure of a cluster type is used. Only cluster head stores the reliability information of the nodes in a block and then, this can be spread. In addition, we applied block generation difficulty automatic setting technique using the number of nodes selecting cluster head and the reliability of cluster head to prevent the spread of wrong blocks. This can prevent block generation and spread by malicious nodes. The superior performance of the proposed technique can be verified by comparing experiments with the SAODV technique.

• Journal of Industrial Convergence
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• v.21 no.2
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• pp.117-123
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• 2023

In the fintech environment, Smart phones are mainly used for various service. User authentication technology is required to use safe services. Authentication is performed by transmitting authentication information to the server when the PIN or password is entered and touch the button completing authentication. But A post-attack is possible because the smudge which is the trace of using screen remains instead of recording attack with a camera or SSA(Shoulder Surfing Attack). To prevent smudge attacks, users must erase their fingerprints after authentication. In this study, we proposed a technique to determine whether to erase fingerprints. The proposed method performed erasing fingerprint which is the trace of touching after entering PIN and designed the security keypads that processes instead of entering completion button automatically when determined whether the fingerprint has been erased or not. This method suggests action that must erase the fingerprint when entering password. By this method, A user must erase the fingerprint to complete service request and can block smudge attack.

• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.6
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• pp.20-28
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• 2013

The purpose of this study was to compare the ultra-violet(UV) radiation under the landscaping shade facilities and tree with natural solar UV of the outdoor space at summer middays. The UVA+B and UVB were recorded every minute from the $20^{th}$ of June to the $26^{th}$ of September 2012 at a height of 1.1m above in the four different shading conditions, with fours same measuring system consisting of two couple of analog UVA+B sensor(220~370nm, Genicom's GUVA-T21GH) and UVB sensor(220~320nm, Genicom's GUVA-T21GH) and data acquisition systems(Comfile Tech.'s Moacon). Four different shading conditions were under an wooden shelter($W4.2m{\times}L4.2m{\times}H2.5m$), a polyester membrane structure ($W4.9m{\times}L4.9m{\times}H2.6m$), a Salix koreensis($H11{\times}B30$), and a brick-paved plot without any shading material. Based on the 648 records of 17 sunny days, the time serial difference of natural solar UVA+B and UVB for midday periods were analysed and compared, and statistical analysis about the difference between the four shading conditions was done based on the 2,052 records of daytime period from 10 A.M. to 4 P.M.. The major findings were as follows; 1. The average UVA+B under the wooden shelter, the membrane and the tree were $39{\mu}W/cm^2$(3.4%), $74{\mu}W/cm^2$(6.4%), $87{\mu}W/cm^2$(7.6%) respectively, while the solar UVA+B was $1.148{\mu}W/cm^2$. Which means those facilities and tree screened at least 93% of solar UV+B. 2. The average UVB under the wooden shelter, the membrane and the tree were $12{\mu}W/cm^2$(5.8%), $26{\mu}W/cm^2$(13%), $17{\mu}W/cm^2$(8.2%) respectively, while the solar UVB was $207{\mu}W/cm^2$. The membrane showed the highest level and the wooden shelter lowest. 3. According to the results of time serial analysis, the difference between the three shaded conditions around noon was very small, but the differences of early morning and late afternoon were apparently big. Which seems caused by the matter of the formal and structural characteristics of the shading facilities and tree, not by the shading materials itself. In summary, the performance of the four landscaping shade facilities and tree were very good at screening the solar UV at outdoor of summer middays, but poor at screening the lateral UV during early morning and late afternoon. Therefore, it can be apparently said that the more delicate design of shading facilities and big tree or forest to block the additional lateral UV, the more effective in conditioning the outdoor space reducing the useless or even harmful radiation for human activities.

• Journal of the Korean Institute of Gas
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• v.16 no.6
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• pp.128-135
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• 2012

In this paper, we proposed a system and a scenario to raise efficiency of gas safety management by developing wireless ZigBee communication modules, smart-home gas safety appliances and the system suitable for gas safety. Our designed system consists of a micom gas meter, an automatic extinguisher, sensors, and a wall-pad. A micom-gas-meter monitors gas flow, gas pressure, and earthquake. An automatic fire extinguisher checks combustible gas leaks and temperature of $100^{\circ}C$(cut off) and $130^{\circ}C$(fire). Sensors measure smoke and CO gas. In our novel system, a micom-gas meter cut off inner valve with warnings, an automatic fire extinguisher cut off middle valve and spray extinguishing materials, and sensors generate signals when detecting smoke and CO and then take a next action. Gas safety appliances and sensors automatically takes measures, and transmit those information to a wall-pad. The wall-pad again transmits real time information to server. Users can check and manage gas safety situations by connecting BcN server through web or mobile application. We hereby devised scenarios for gas safety and risk management based on the smart, and demonstrated their efficiency through test applied to filed.

• Journal of the Korea Convergence Society
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• v.11 no.7
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• pp.19-24
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• 2020

WHO declared a global pandemic on March 11th for Corona 19. However, there is a situation where you have to go to building for face-to-face education or seminars for economic and social activities. The first check method of COVID-19 infection is to measure body temperature, so the primary entrance and exit is blocked for near-field body temperature measurement. However, since it is troublesome to check directly, thermal camera is installed at the entrance of the building, and body temperature is measured indirectly using the infrared camera to control access. In case of middle and high schools, universities, and lifelong education center, we need a system that is possible to interoperate with attendance checks and automatically recognizes whether to wear masks and can authenticate students. We proposed the system that is to confirm whether to wear a mask with a camera that is embedded in a smart mirror, and that authenticates the user through voice recognition of the user who wants to enter the building by using voice recognition technology and determines whether to enter them or not. The proposed system can check attendance if it is linked with near-field temperature measurement and attendance check APP of student's smart phone.

• Journal of the Korean Institute of Gas
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• v.16 no.6
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• pp.67-72
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• 2012

In this study, the leak-free performance and sealing endurance safety of CNG fueling nipple in which are related to the contact normal stress and equivalent true stress have been analyzed for CNG automobile using a finite element analysis. For the conventional circular o-rings and new double-lip o-rings with an initial compression rate of 15 percentages, the leak-free performance of double-lip o-rings with two contact sealing spots is 41% higher than that of the conventional circular o-rings with a contact sealing spot. The FEM computed results present that the leak-free endurance safety of double-lip o-rings with two contact sealing spots is 5% higher than that of the conventional circular o-rings for initial compression ratio of 15 percentages and a gas compression pressure of 8MPa. And, the maximum equivalent true stress of double-lip o-rings is 10.2% higher than that of the conventional circular o-rings for the leak-free endurance safety. This means that the double-lip o-ring may guarantee the extended sealing life compared to that of a conventional circular o-ring.

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

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.239-242
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• 2005

고분자 전해질형 연료전지에서는 수소이온의 이온전도성 저하를 방지하기 위하여 외부에서 가습하여 주는 방식이 일반적이지만, 가습에 소요되는 부품을 일부라도 제거할 경우 연료전지의 효율은 높이고 제작단가도 경감할 수 있다. 이를 위하여 저가습 및 무가습 실험을 수행하였으며, 정확한 data의 수집과 시험장비의 자동제어를 위하여 National Instrument사의 compact field point (cFP)를 사용하였다. 무가습 실험 중 stack의 안정성 측면을 고려하기 위하여 수소연료가 부족하거나 갑작스런 voltage drop이 발생할 경우 LabVIEW logic에 의한 stack 보호용 자동차단 시스템을 구현하였다. Humidifier와 heater의 온도를 조절하여 공급유체의 상대습도 및 온도를 각각 조절하였으며, 이에 필요한 이론적 온도는 Antoine equation을 사용하여 산정하였다. Anode와 cathode 양측 $100\%$ 가습 경우를 기준으로 가습량을 조절하면서 실험을 수행하였으며 성능 차이를 그래프로 도시하여 양측의 변화에 대한 영향을 볼 수 있도록 하였다. Stack의 온도가 $70^{\circ}C$이고 양측 무가습일 경우에 성능 측정이 불가능하여 stack의 온도를 저온에서부터 변화시키면서 무가습 성능을 실시간으로 측정하여 보았다 일반적으로 hydronium ion은 anode측에서 cathode측으로 계속 이동하여야 전기를 생성할 수 있으므로 cathode측 무가습이 anode측 무가습보다 성능이 더 잘 나오는 것으로 예측하였으나 이와 반대되는 경향의 실험 결과를 얻었다. Anode측 무가습과 cathode측 무가습의 standard deviation은 anode 무가습일 경우가 크게 발생하였고 양측 무가습일 경우는 stack의 온도가 높을수록 크게 관찰되었다. 이와 같은 현상은 공기중의 상대습도와 back diffusion등에 영향을 받을 수 있으므로 각종 변수들의 영향을 분리하여 관찰할 수 있는 실험을 수행중에 있다.