In the event of fire, how quickly occupants can hear, see, and/or smell the fire and then exit the building are important for reducing the number of potential casualties. After a person or an automatic fire-detection system detects a fire, an installed emergency alarm system is used to alert building occupants about the fire. The emergency alarm system plays an important role in alerting the occupants to the fire by emitting a high-pitched sound when the fire is initially detected. Although bells and electronic sirens can both be used in fire-alarm systems, usually only bells are used in most commercial fire alarms except for a few fire extinguishers. Recently, however, the development of circuit integration technology and subsequent competitive pricing and improved performance have fostered an environment favorable for the widespread application of electronic sirens. However, because electronic sirens that emit various sounds will likely confuse building occupants used to hearing familiar-sounding conventional fire-alarm bells, electronic sirens must be engineered to sound like conventional fire-alarm bells. Therefore, in this study, experiments were conducted to measure the specific sound pressure and frequency characteristics of commercially available fire-alarm bells and electronic sirens, and their characteristics were reviewed. In addition, the differences between the bells and sirens were analyzed to develop a plan for supplementing warning sounds of electronic sirens.

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In recent years, requirement for the consideration of global buckling due to high pressure/high temperature (HP/HT) condition has increased in the detailed design of offshore pipelines on a seabed. The interaction between pipeline and seabed including support structures or sleepers gives a significant effect on buckling behavior. Global lateral buckling analysis has been carried out to assess the stability of offshore HP/HT pipelines considering the interaction between HP/HT submarine pipeline system/foundation structure and seabed. A non-linear finite element method is used in the present static analysis using the ABAQUS program. The FE model considers concrete sleepers as well as 3-D profile of the seabed. The stress distribution and lateral amplitude of the pipeline were evaluated and remedial measures were suggested to ensure that pipe stresses and strains are kept within allowable limits. Sleepers are designed as a buckle trigger which can provide artificial imperfection to allow pipe to move laterally and mitigate axial force. Comparative study could provide design strategy of pipeline related to sleeper supports.

The present paper describes general methodology and simulation results for risers coupled with a floating vessel. Equations of extensible riser and their finite element formulation are derived and presented in the form, which is suitable to accommodate the effects of contents flow and VIV. Nonlinear riser equations are solved by iterations in global variables. The analysis procedure of coupling between the several risers and the vessel dynamics is described in details. The low frequency coupled vessel motion and riser behavior are numerically simulated. The internal flow effects are investigated in uniform and pulsating cases. It is found that the internal content flow makes the riser stiffer and the riser curvature reduced. In the VIV analysis, the VIV exitation zone of the riser is obtained based on eigen frequencies and the maximum response is evaluated from the corresponding eigen-shapes in the VIV region.

In this study, Exit light installed in offices, malls, hospitals, and factories were analyzed to analyze the luminance performance of CCFL and LED light sources. In addition, fire protection products with electrical characteristics such as Exit light may change their performance due to ambient temperature, humidity, and dust. So it was extracted by installation place and analyzed its characteristics. As a result of the experiment, Exit light for CCFL type showed the value of 'ratio of luminance 2' for large, medium and small. Considering that the reference value was 'lower than 9', the value was very good and it can be seen that there is almost no change in ratio of luminance due to aging. The Exit light for LED type showed a value of 'ratio of luminance 5', which means that the light on the display surface is not uniform. In addition, there was almost no change in ratio of luminance due to ageing, but the ratio of luminance was larger than Exit light for LED type. This is an unsatisfactory result from a visual point of view. To improve this, it is necessary to disperse the light of LED light source and strengthen the regulation on ratio of luminance.