• Journal of Aerospace System Engineering
• /
• v.16 no.1
• /
• pp.70-80
• /
• 2022

An aerial refueling provides for extension of operational time and range for aircraft and enhances mission effectiveness, hence it application by most military aircrafts. The receiver aircraft should have the aerial refueling clearance that is established by performing technical and operational compatibility assessments to certify it for aerial refueling with a specific tanker model. The compatibility assessment includes aerial refueling handling qualities, functional, fuel, lighting system testing and it is finally verified through flight testing. However, since aerial refueling compatibility assessments have never been performed in Korea, there is no experience to determine the test requirements and the scope and size of the test program for a new development aircraft. This paper therefore introduces the common techniques of aerial refueling and aerial refueling flight test methods to understand the aerial refueling FCS (Flight Control System), OFP (operational flight program) and system validation, and aerial refueling envelope clearance of a fixed wing aircraft for a boom and receptacle refueling system that is being introduced into Korea Air Force.

• Journal of the Korean Professional Engineers Association
• /
• v.16 no.1
• /
• pp.4-12
• /
• 1983

Data communication has historically evolved from leased lines, to use of the public telephone network, and eventually to dedicated(exclusive) data networks. It requires an enormous amount of money for establishing a separate and independent data network at the beginning stage. No country has ever adopted this method In the Republic of Korea too the age of leased circuits is passing and it is scheduled to open the public telephone network to the data transmission and to install packet mode processor in the last half of 1983. This paper presents a survey on characteristics of the public telephone network in Seoul and a future development of the data communication of Korea.

• Polymer(Korea)
• /
• v.26 no.1
• /
• pp.9-17
• /
• 2002

The free radical bulk copolymerizations of perfluoroalkylethyl acrylate(FA) containing perfluoro group ($CF_3(CF_2)_nCH_2CH_2$-; n=5, 7, 9, 11) with styrene were conducted at $60^{\circ}C$ using AIBN as an initiator. Reactivity ratios($r_1$, $r_2$) were determined from monomer feed compositions and the NMR spectroscopically measured copolymer compositions using Kelen-Tudos method. The structures of copolymers were characterized with FT-IR and $^1H-NMR$ analysis. Their thermal properties investigated with DSC and TGA were decreased with increasing the content of fluorinated acrylate in the copolymer. Their surface free energies were calculated with measuring contact angles of the copolymers and PMMA blends with a small amount of them.

• Journal of Digital Convergence
• /
• v.14 no.3
• /
• pp.13-23
• /
• 2016

The purpose of this convergence study was to describe Medical Service Providers and Consumers' perception of the PHN system, and of the Quality of nursing provided by male nurses. This study was a cross-sectional survey. The subject group included medical service providers and consumers. Data were analyzed using descriptive statistics, Chi-square and t-test using SPSS 19.0. 77.3% of providers and 66.2% of consumers agree with the PHN system. 81.4% of providers and 70.8% of consumers agreed with the statement that the nurse is the most qualified public health worker. Period of service showed statistically significant differences according to the group (t=7.56, p=.03). The development of nursing experts was identified as an important strength of the PHN. Quality of nursing Male wasn't statistically significants between groups. Compared to earlier studies, it is to suggest a study that confirms preliminary nurses' psychiatric, social, and communicational nursing.

• Applied Chemistry for Engineering
• /
• v.4 no.4
• /
• pp.770-775
• /
• 1993

Chemical structure of poly(ethylene terephthalate-co-1, 4-cyclohexylene dimethylene terephthalate), P(ET-CT) copolyesters was investigated by High Resolution NMR analysis. The copolymer composition and isomeric ratio were determined by methylene resonance peaks which were separated into three peaks corresponding to ET, trans CT and cis CT units, respectively. The copolymer sequence distribution was evaluated from the carbon resonance peaks connected to carbonyl groups in benzene, indicating died distribution. According to statistics model, these copolyesters are almost random copolymers. The copolymer sequence distribution could be simulated and its averaged length was calculated by random copolymer statistics.

• Polymer(Korea)
• /
• v.25 no.2
• /
• pp.208-217
• /
• 2001

PET/BPA copolymer of terephthalic acid, bisphenol-A and ethylene glycol was melt-pressed and quenched in ice water. This copolymer film was drawn by capillary rheometer. Shrinkage, crystallinity, morphology, thermal, dynamic mechanical, and mechanical properties of these copolymer films were investigated. The PET/BPA copolymer film exhibited T$_{m}$ lower than that of PET film. The crystallinity and density of these drawn copolymer films increased with draw ratio and draw rate but decreased with draw temperature. The tensile strength and tensile modulus of the copolymer films increased with draw ratio but decreased with draw temperature. Shrinkage of the drawn copolymer film decreased with draw ratio and draw rate.e.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.19 no.2
• /
• pp.473-482
• /
• 2024

This study utilized virtual reality to construct a simulated public restroom environment to identify potential hazards. The objective was to discern actual risks in real-world public restrooms through this virtual setup. During the virtual restroom experience, data from the built-in 3-axis accelerometer and gyroscope sensors of testor's smart phones were collected. Analysis of this data helped in identifying spatio temporal factors impacting the users. The determination of these factors as risk elements was based on an evaluation algorithm grounded in data analysis.

• Electrical & Electronic Materials
• /
• v.4 no.1
• /
• pp.12-18
• /
• 1991

각종 monomer를 공중합시킨 고분자 필름의 X선 유기 TSC(thermally-stimulated current)를 측정하고 polyethylene(PE)의 절연성능 개선의 관점에서 공중합 monomer의 영향에 대하여 검토하였다. PE의 X선 유기 TSC 피이크는 결정화도가 높을 수록 고온측으로 이동하였다. X선 유기 TSC에서 피이크는 공중합에 의하여 Br 및 F원자가 0.2~0.4eV의 전자 trap이 도입된 것으로 생각된다.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
• /
• 2003.07a
• /
• pp.241-244
• /
• 2003

공중 무선랜 서비스의 확산으로 무선랜은 무선 인터넷의 중요한 매체로 이용되고 있다. 그러나 사용자의 프라이버시(Privacy) 문제나 접근제어(Access Control) 같은 인증 (Authentication) 문제와 함께 과금(Accounting) 및 빌링(Billing)의 문제가 중요한 이슈로 대두되고 있다. 본 논문에서는 공중 무선랜의 이동환경을 위한 Diameter 기반 선불 과금 모델을 제안하고, 그에 대한 검증 결과를 함께 제시한다. 최종적으로 제안된 선불 과금 모델은 공중 무선랜에서의 패킷과금을 지원하기 위한 요구사항들을 충족시키고, 글로벌 로밍 서비스를 위한 이동성을 향상하는 기반 기술로서 이용되기를 기대한다.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 2010.04a
• /
• pp.443-447
• /
• 2010

본 연구에서는 우리나라의 소 중 대형 산불의 공중진화 방화선 구축형태에 대하여 제안하였다. 산불확산은 현장의 지세, 경사, 바람, 수종 등에 영향을 받으므로 공중진화 방화선을 구축할 때에는 연소방향 및 형태, 강도 등을 분석한 후 진화작업을 실시하여야 하며, 공중진화 방화선 형태를 A형에서 M형까지 13개로 제안하였다.