• Fire Science and Engineering
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• v.25 no.6
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• pp.120-126
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• 2011

Recently luminous egress guide-lines are introduced for the fire safety of residents in the multi-use buildings such as Gosiwon. Little literature, however, on the quantitative and qualitative estimation for the egress performance of the luminous egress guide-lines can be found. This study carried out experimental investigations to evaluate the egress performance of the existing egress guide-lights and new luminous egress guide-lines. The results showed that both luminous egress guide-lines and egress guide-light satisfied the basic performance of KFI requirements. Under the 7 % smoke transmittance, however, luminous egress guide-lines showed 3 times longer visibility and less evacuation time than egress guide-lights. The evacuation density and smoke transmittance have significant effect on the evacuation time increase without the luminous egress guide-lines, however little effect with the installation.

• Journal of Digital Convergence
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• v.18 no.9
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• pp.221-228
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• 2020

The purpose of this study is to examine the relationship between the sexual knowledge and contraceptive attitude and gender sensitivity of the nursing students. The data were collected from 169 nursing students from November 2019 to December 2019 at U city and analyzed using descriptive statistics, t-test, ANOVA, Scheffe test, Pearson's correlation analysis, and multiple regression. As a result of this study, the contraceptive attitude of nursing students showed a positive relationship with gender sensitivity(r=0.357, p<0.001), and it was the factor that affected gender sensitivity(β=0.356, p<0.001). Therefore, it is necessary to make and apply the programs to enhance the gender sensitivity for the nursing students, and the college and the government supports are required to increase the contraceptive attitude.

• Journal of the Korean Institute of Telematics and Electronics
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• v.12 no.4
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• pp.7-14
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• 1975

A significant new technique in the dsvelopment of micro-wave circuits is the process of untilization of coupled lines in the transverse electro-magnetic field. The bases for this technique are the application of even-and odd-mode characteristic impedances of the transmission line. This article describes the properties of directional couplers and explains a prccfdure usrd to design micro-strip directional couplers with the aid of the computer. The article also describes the experimental results obtained from seven microstrip couplers, which were built to verify the computer program and the approximate solutions. It can be seen that in cases at X-band where couplings of 10 to 20dB are required, the computer program and approximate solutions will produce good results.

• Journal of the Korean Geotechnical Society
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• v.18 no.5
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• pp.55-65
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• 2002

Model tests were performed to investigate the mechanism of lateral earth pressure on a buried pipe, which was installed in a plastic flowing soil mass undergoing lateral movement. On the basis of failure mode tests, the equation of lateral earth pressure to apply Maxwell's visco-elastic model was proposed to consider the soil deformation velocity. Through a series of model tests of differential soil deformation velocity, lateral earth pressure of theoretical equation was compared with experimental results. When lateral soil movement was raised, the lateral earth pressure acting on buried pipe increases linearly with the soil deformation velocity. It shows that the lateral earth pressure on buried pipe is largely affected by soil deformation velocity. When plastic soil movement was raised, lateral earth pressure predicted by theoretical equation showed good agreement with experimental results. Also, coefficient of viscosity by theoretical equation had a good agreement with direct shear test results.

• Journal of Korean Society of Transportation
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• v.19 no.4
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• pp.97-108
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• 2001

A dynamic transportation management should be applied specially in AM peak because AM peak is more critical than PM peak in traffic volume and demand. AM peak trip can be characterized by commuting and schooling. which have the high level of usage on public transportation, and constraint on arrival time. So transportation management applied in AM peak could deal with a mode choice and an arrival time constrain. Researchers were involved in the dynamic transportation assignment models for management of congested traffic network. But, there were no models which considered a mode choice and an arrival time constrain should be included in management of AM peak. So there are limits to use exist models to control and analyze AM peak traffic. In this study, it is proposed the combined dynamic transportation model, considering a mode choice and the start time selection with arrival time constrains, based on Ran and Boyce's model. The proposed model is verified the compatibility by applying to the newly designed time space expanded network. The result shows that proposed model consistent with dynamic user optimal travel pattern. From this we certificate the applicability of the proposed model to control and analyze AM peak traffic.

• Journal of the Korean Geotechnical Society
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• v.31 no.9
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• pp.17-27
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• 2015

We perform a series of experimental tests to evaluate whether the shear strength of clean sands can be reliably predicted from shear wave velocity. Isotropic drained triaxial tests on clean sands reconstituted at different relative densities are performed to measure the shear strength and bender elements are used to measure the shear wave velocity. Laboratory tests reveal that a correlation between shear wave velocity, void ratio, and confining pressure can be made. The correlation can be used to determine the void ratio from measured shear wave velocity, from which the shear strength is predicted. We also show that a unique relationship exists between maximum shear modulus and effective axial stress at failure. The accuracy of the equation can be enhanced by including the normalized confining pressure in the equation. Comparisons between measured and predicted effective friction angle demonstrate that the proposed equation can accurately predict the internal friction angle of granular soils, accounting for the effect of the relative density, from shear wave velocity.

• Applied Chemistry for Engineering
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• v.9 no.7
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• pp.1085-1089
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• 1998

The well-established nitric acid-sulfuric acid mixed acid process for the nitration of aromatic compounds has serious problems due to the large amount of waste acids and severe reaction conditions. Nitration of toluene can be conducted using nitrogen dioxide and ozone instead of mixed acid. We found that conc. nitric acid increased the reactivity as catalyst and the amount of nitrogen dioxide controlled the extent of nitration. Dinitration proceeded to more than 92 mole % conversion within 2 hr at $0^{\circ}C$ with 6 eq. of nitrogen dioxide and 2 eq./hr of ozone flow. Toluene completed mononitration within 30 min using 3 eq. of nitrogen dioxide, 3 eq. of nitric acid, and 1.5 eq./hr of ozone flow. As a clean process of aromatic nitration, this method is expected to replace the present process which causes the environmental problems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.475-480
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• 2016

Abandoned empty houses are largely left neglected as unused space, due to the slowdown in the real estate market that has resulted from the declination of urban functions. This research aims to analyze the characteristics of the City of Detroit's policies and regeneration efforts regarding abandoned houses, based on the perspective of unused space. This is expected to provide the baseline data for similar efforts to be applied to abandoned houses in the Korean context, thus preventing the decline of urbanism by adopting relevant policies and regeneration efforts. Some of the key features of the City of Detroit's regeneration efforts are: 1) the active participation of residents and open-data policies, 2) the diversification of regeneration strategies depending on the potential of the unused space, and 3) securing differential plurality of the regeneration processes.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.105-105
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• 2011

라오스는 최근 수년간 연 7~8%의 높은 GDP 성장률을 달성할 만큼 전세계 투자가 집중되고 있다. 라오스 수도인 비엔티안시를 비롯한 라오스의 메콩강변 주요도시는 매년 크고 작은 홍수로 인해 인명 및 재산피해가 지속되고 있으나, 현재 라오스에 대한 국가차원의 홍수저감 및 관리 프로그램이 전무한 실정에 있어, 라오스의 급속한 발전속도와 함께 홍수위험도가 급증될 것으로 예상된다. 특히, 라오스 주요도시 중 홍수위험도가 가장 높을 것으로 예상되는 비엔티안시에서 홍수로 인한 주민의 인명 및 재산피해를 방지하기 위해 홍수방어대책을 마련하는 것이 매우 시급한 실정에 있다. 따라서, 본 연구에서는 라오스 비엔티안시를 대상으로 메콩강 홍수의 저감 및 관리 방안을 제시하였다. 메콩강의 수문학적 특성을 분석하기 위해 메콩강 유역, 기후 및 기상조건, 유출특성을 검토하였고, 과거 메콩강의 홍수사례, 홍수수문곡선 등을 토대로 메콩강에 적합한 홍수규모인자로서 첨두홍수량, 홍수체적, 홍수지속시간을 제시하였다. 홍수체적과 첨두홍수량의 상관도를 분석하여 과거 발생한 홍수의 규모를 정량화하였으며, 확률분석을 통해 계획빈도에 대한 홍수체적 및 첨두홍수량을 산정하였다. 또한, 과거 93개년 홍수사상을 토대로 홍수지속시간과 첨두홍수량, 홍수체적의 상관성을 분석하고, 홍수지속시간이 첨두홍수량, 홍수체적의 함수로 표현되는 회귀식을 도출하여 비엔티안시의 제방계획에 고려될 홍수지속시간을 산정하였다. 마지막으로 본 연구에서는 홍수위험요소를 홍수위험, 홍수노출, 홍수취약성 등 3개의 구성요소로 구분하였고, 각 홍수위험요소별 비엔티안시의 현상태를 정성적으로 평가하여 현재 비엔티안시에 적합한 홍수저감 및 관리방안을 제시하였다.

• Fire Science and Engineering
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• v.27 no.4
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• pp.7-12
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• 2013

Recently, the risk of fire outbreak is going up because of newly developed combustible materials are intended to apply more. Especially the steel framed structure can lose its load-bearing capacity when it is exposed to higher temperature condition such as a fire. So the pre-evaluation of fire resistance of the structure is very essential that the mechanical properties of yield strength and elastic modulus and thermal properties such as conductivity and linear expansion be required. To get the databases for SM 400 or welding structural steels at high temperature, various temperature conditions were used for deriving the yield strength, elastic modulus, linear expansion, and conductivity and the results were compared to those of SS 400, ordinary structural steel, respectively.