• Journal of Digital Convergence
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• v.12 no.10
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• pp.243-252
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• 2014

Many researches about the effect on politics, economics and Sociocultural phenomenon using the social media are in progress. Authors utilized NAVER Trend most famous web browsing service in korea, NAVER Blog social media, NAVER Cafe service and Open Data(API) and also used temperature, humidity index data of Korea Meteorological Administration. This study analyzed a change of the public's emotion in korea using Cluster analysis of vocabulary of taste among its of feelings and senses. K-means clustering was followed by decision of the number of groups which was used Chi-square goodness of fit test and ward analysis. Eight groups was made and it represented sensitive vocabulary. By Discriminant analysis, eight groups decided by Cluster analysis has 98.9% accuracy. The change of the public's emotion has capability to predict people's activity so they can share sensibility and a bond of sympathy developed between them.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.3
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• pp.485-492
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• 2008

Computers used fer light-weight computing environments are considerably limited in resources and performance running in ubiquitous environment. Because of the limited resources, it is difficult to apply existing security technologies to the light-weight computers. In this paper, light-weight security software is implemented using RC-5 encryption and SHA-1 authentication algorithm which is appropriate for light-weight computing environments. The design of components based on security software of a light-weight computer application and the test-bed for security software are presented. The simulation verifies the correctness of the security software. The architecture of the light-weight and reconfigurable security software for light-weight computer applications is proposed. The proposed security software is small size and provides reconfigurable security library based on the light-weight component and the software manager that configures software platform is loaded with the library at the time it is needed.

• Korean Journal of Metals and Materials
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• v.46 no.4
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• pp.199-208
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• 2008

This study is concerned with effects of complex oxides on Charpy impact toughness of heat affected zone (HAZ) of API X80 linepipe steels. Three kinds of steels were fabricated by varying alloying elements such as Ti, Al, and Mg and hot-rolling conditions to form complex oxides, and their microstructures and Charpy impact properties were investigated. The number of complex oxides present in the steel containing excess Ti, Al, and Mg was twice larger than that in the conventional steels, while their size ranged from 1 to $3{\mu}m$ in the three steels. After the HAZ simulation test, the steel containing a number of oxides contained about 20 vol.% of acicular ferrite in the simulated HAZ, together with bainitic ferrite and martensite, whereas the HAZ microstructure of the conventional steels consisted of bainitic ferrite and martensite with a small amount of acicular ferrite. This formation of acicular ferrite in the oxide-containing steel was associated with the nucleation of acicular ferrite at complex oxides, thereby leading to the great (five times or more) improvement of Charpy impact toughness over the conventional steels.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.2
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• pp.83-92
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• 2007

In connectionless packet network, if a sender encrypts packets by block chaining mode and send it to receiver, the receiver should decrypt packets in encrypted order that is not received order. Therefore, the performance and efficiency are lowered for crypto communication system. To solve this problem, we propose packet encryption scheme for connectionless packet network that can decrypt the packets independently, even if the received order of packets are changed or packets are missed. The scheme makes new IV(Initial Vector) using IV that created by key exchange process and salt that made by random number. We propose extended Cryptoki API that added packet encryption/decryption functions and mechanism for improving convenience and performance. We implement the scheme and get result that the performance increased about $1.5{\sim}l5.6$ times compare with in case of implementing using Cryptoki API in the test environment.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2014.06a
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• pp.18-21
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• 2014

본 논문은 한국정보통신기술협회(TTA)에서 제정된 "HTML5 기반 스마트 TV 플랫폼 수신기 적합성 시험" 표준(TTAK.KO-07.0119)에 따라 구축한 표준 적합성 시험환경에서 시험 도구의 테스트 케이스 개발에 활용되는 스마트 TV 테스트 프레임워크 설계와 구현에 대한 내용을 소개한다. 표준으로부터 도출된 많은 개수의 테스트 항목에 대한 테스트 케이스를 효율적으로 개발하기 위해 테스트 내용 외의 공통적으로 수행되는 코드부분(테스트 케이스의 정의, 기본 UI, 서버와의 통신 등)을 추상화하고, 테스트 케이스 개발 자체의 난이도를 줄이기 위해 사용하기 쉬운 API 를 제공하는 프레임워크가 필요하다. 본 논문에서는 스마트 TV 테스트 프레임워크의 소프트웨어 구조를 소개하고, 테스트 케이스 개발에 활용하는 테스트 서술 API, 테스트 결과를 사용자에게 일관되게 보여주는 테스트 프레임워크 UI, 그리고 테스트 결과를 수집하고 서버에 전송하는 테스트 리포터의 설계와 구현 내용에 대해 소개한다.

• Corrosion Science and Technology
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• v.4 no.3
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• pp.95-99
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• 2005

Wheel test and potentiodynamic polarization methods were used to evaluate the relative effectiveness of some hydrogen sulfide corrosion inhibitors for the wet gas pipeline API 5L grade X 65 steel. Five commercially corrosion inhibitors have been studied in the deoxygenated produced water solutions containing 10 ppm and 100 ppm of hydrogen sulfide. Based on the experiment results the steel corrosion inhibition mechanism in discussed and two most effective corrosion inhibitors are selected.

• Clinical and Experimental Pediatrics
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• v.63 no.3
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• pp.104-109
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• 2020

Background: It is challenging to diagnose asthma in preschool children. The asthma predictive index (API) has been used to predict asthma and decide whether to initiate treatment in preschool children. Purpose: This study aimed to investigate the association between questionnaire-based current asthma with API, pulmonary function, airway hyperreactivity (AHR), fractional expiratory nitric oxide (FeNO), and atopic sensitization in preschool children. Methods: We performed a population-based cross-sectional study in 916 preschool children aged 4-6 years. We defined current asthma as the presence of both physician-diagnosed asthma and at least one wheezing episode within the previous 12 months using a modified International Study of Asthma and Allergies in Childhood questionnaire. Clinical and laboratory parameters were compared between groups according to the presence of current asthma. Results: The prevalence of current asthma was 3.9% in the study population. Children with current asthma showed a higher rate of positive bronchodilator response and loose and stringent API scores than children without current asthma. The stringent API was associated with current asthma with 72.2% sensitivity and 82.0% specificity. The diagnostic accuracy of the stringent API for current asthma was 0.771. However, no intergroup differences in spirometry results, methacholine provocation test results, FeNO level, or atopic sensitization rate were observed. Conclusion: The questionnaire-based diagnosis of current asthma is associated with API, but not with spirometry, AHR, FeNO, or atopic sensitization in preschool children.

• Journal of Platform Technology
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• v.10 no.4
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• pp.25-38
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• 2022

Recently, it is reported that the Korean Unmanned Aerial Vehicle (UAV) interface protocol (K-4586) based on STANAG-4586 is being developed to secure interoperability between UAVs. The core elements of the K-4586-based Unmanned Aircraft System (UAS) are the Core UAV Control System (CUCS), Vehicle Specific Module (VSM), Data Link Interface (DLI), and C4I systems. In UAS based on K-4586, the DLI function for transmitting and receiving messages to link UAVs is included in VSM and CUCS respectively. The Generator/Analyzer (G/A) tool is an apparatus that is developed for protocol conformance verification for VSM and CUCS, and G/A tools with DLI message transmitting and receiving should be developed separately. Core applications (VSM, CUCS, DLI) and G/A tools based on K-4586 may be developed independently depending on the developers. If the DLI message modules are different for each developer, the scope and results of protocol conformance verification will be dissimilar, and some problems may happen during system integration. In this study, common DLI message module based on the API was designed to provide the DLI message transmitting and receiving function necessary to the development of core applications and the protocol conformance verification tool of based on K-4586. When applying the proposed common DLI message module, it can be expected to shorten the UAS system development period and reduce costs, and ensure conformance of protocol. In this paper, the design and implementation method for the common DLI message module based on API was proposed and the results of functional test was described.

• Corrosion Science and Technology
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• v.3 no.2
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• pp.81-86
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• 2004

The sulfide stress corrosion cracking (SSCC) resistance of API X70 grade steel weldment has been studied using SSCC test in NACE TM-O177 method A. Also, microstructures and hardness distribution of weldment was investigated. The microstructure of SAW joint composed ferrite, pearlite and some MA constituent. Instead of hardening in CGHAZ, softening on the HAZ near base metal occurred. The low carbon TMCP type steel used for SAW showed softening behaviour in the HAZ adjacent to base metal, which was known to be closely related with the SOHIC (stress oriented hydrogen induced cracking). The SSC testing revealed that the API X70 SAW weld was suitable for sour service, satisfying the NACE requirements. By suppressing softening in the ICHAZ region, the SSCC resistance of low carbon TMCP steel welded joints could be more improved.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.211-216
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• 2007

The objective of this paper is to present the results of an experimental and a finite-element investigation into the behavior of X80 grade pipes subjected to bending. For the pipe specimens comprising the test series, different D/t is applied to be representative of those that can be expected in the field. Results from the numerical models are checked against the observations in the testing program and the ability of numerical solutions to predict pipe moment capacity. curvatures. and buckling modes is established. A finite-element model was developed using the finite-element simulator to predict the local buckling behavior of pipes. The comparison between the numerical and the experimental results demonstrates the ability of the analytical model to predict the local buckling behavior of pipes when deformed well into the post-yield range.