• Journal of the Korean Institute of Gas
• /
• v.5 no.4 s.16
• /
• pp.70-78
• /
• 2001

In order to find out which equipment failures were mostly contributed to the rupture of a continuous stirred tank reactor, the sensitivity analysis was carried out. The uncertainty of likelihood of the rupture of reactor was studied by the uncertainty analysis. And the cost effectiveness analysis resulted in the recommendation of the exchange with a better reliable unit if you want to maintain the process efficiently from the view point of cost. The uncertainty analysis showed that the likelihood of catastrophic rupture of the reactor was distributed from $8.09{\times}10^{-04}$ to $5.50{\times}10^{-02}/year$. As a result of cost-effectiveness analysis, it was proposed to exchange the voting logic unit for a better safer system.

• KIEAE Journal
• /
• v.13 no.5
• /
• pp.79-88
• /
• 2013

This study creates the evaluation criteria to analyze the $CO_2$ emission quantity in the complex of apartment house among domestic buildings and proposes how to calculate the $CO_2$ emission quantity by the only simple information of apartment house. The study shows that in order to create the index of carbon emission evaluation criteria, $CO_2$ emission quantity for its input materials in these 27 apartment houses are 445,412g-$CO_2/m^2$ for apartment building, 474,322g-$CO_2/m^2$ for the basement parking lot, 483,523g-$CO_2/m^2$ for welfare facility, 729,957g-$CO_2/m^2$ for sales facility, 743,560g-$CO_2/m^2$ for other facility, 26,782g-$CO_2/m^2$ for public facility, 43,659g-$CO_2/m^2$ for landscape, 1,113g-$CO_2/m^2$ for indoor facility, 11,251g-$CO_2/m^2$ for outdoor facility and 891g-$CO_2/m^2$ for common temporary based on the average $CO_2$ emission by facility. We can also see the analysis data that in case of using the selected factors only, the rate of error is 7.51% comparing with the emission quantity by using simplified LCA method this study suggests for the whole range of apartment houses and the rate of error is average 3.24% using selective and main materials. And this it is evaluated that we can get the result which is similar to the actual $CO_2$ emission quantity with only the simple information about the apartment house.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.7 no.4
• /
• pp.41-47
• /
• 2012

Railroad rolling stock has long service life and a lot of maintenance cost running on rail by wear and vibration. And it is very important to get optimization of maintenance. This paper want to analyze rolling stock maintenance situation of KORAIL and find out its improvement methods. Especially, the purpose of this paper is to adopt the most effective maintenance period and methods to daily inspection which needs many maintenance manpower in rolling stock. Rolling stock has self-diagnosis function using computer system and the quality of rolling stock has much improved these days but current daily inspection repeat for short period routinely and it is very ineffective. Therefore, the paper adopt improved daily inspection period reflecting the characteristics of rolling stock, and want to secure reliability of rolling stock and minimize maintenance cost.

• Journal of the Korean housing association
• /
• v.18 no.5
• /
• pp.1-10
• /
• 2007

This study is to analyze the residential spatial composition structures of vernacular agricultural village which to be called Wanggok in Yeongdong area. The results of this study are as follows; ${\cdot}$ The backyard of farmhouses is surrounded by a fence and a frontyard is open to the road, so that the spatial realm system from the road to the backyard is classified as public-semi public-private realm. ${\cdot}$ The plan type of this village is mainly composed of ㅡ type Gyeobjib (the two row rooms under one roof) and ㄱ type Gyeobjib, the Anmaru (the inner wood floor to be surrounded with wall) in both of which plays an important role that connects Sarangbang (the men's main room) with Anbang (the women's main room) in the residential space. ${\cdot}$ The particular item that not found out in another area is the Sarangbang kitchen which located to Sarangbang's side wall to be furnished with a fire hole. ${\cdot}$ The houses represent the socio-cultural environmental elements of those built days, such as while Sarangbang is faced on a frontyard to be open to the neighborhood, Anbang is faced on a backyard surrounded with a fence to be closed to the one. ${\cdot}$ The Gyeobjib with Anmaru appeared by cultural transformation connecting the 田-shaped house of Hamgyeongdo with the Gyeobjib with Anmaru of Gangwondo and Gyeongsangbukdo. ${\cdot}$ The ㄱ type Gyeobjib is preferred to ㅡ type Gyeobjib because of the sea wind and the north-east wind occurring by geographical and climatic environment elements, the privacy protection according to look into a frontyard, the muck drainage of cowshed to make use of ground unevenness, the economic gains called material saving and the intention to enlarge the frontyard as to be concentrated in a residential space and etc.

• Journal of Digital Contents Society
• /
• v.18 no.8
• /
• pp.1543-1550
• /
• 2017

Previous research on smartphone has been focused on personal performance, accessibility, and information gaps in information system quality. In order to analyze the relationship between the use of smartphone information and personal characteristics, this study conducted a survey of 300 tourists at Jeju Airport, by using three variables of self-efficacy, 'impulsiveness and demographic variables (age, sex, education level, etc.) of smartphone use with personal characteristics. In conclusion, self-efficacy and impulsiveness seem to be positively related to the use of smartphone because it seems to be a living environment in which the desired information can be acquired within a desired time. In addition, there seems to be a difference between a mobile native environment in which online and offline boundaries are always connected and an environment in which 40 to 50 digital literacies are connected. This can be interpreted as a result of additional analysis.

• Journal of Sensor Science and Technology
• /
• v.24 no.5
• /
• pp.319-325
• /
• 2015

While the conventional personal protective equipments (PPEs) covers a variety of devices and garments such as respirators, turnout gear, gloves, blankets and gas masks, several electronic devices such as personal alert safety system (PASS) and heads-up displays in the facepiece have become a part of firefighters personal protective equipments through past several years. Furthermore, more advanced electronic sensors including location traking sensor, thermal imaging caerma, toxic gas detectors, and even physiological monitoring sensors are being integrated into ensemble elements for better protection of firefighters from fire sites. Despite any electronic equipment placed on the firefighter must withstand environmental extremes and continue to properly function under any thermal conditions that firefighters routinely face, there are no specific criteria for these electronics to define functionability of these devices under given thermal conditions. Although manufacturers provide the specifications and performance guidelines for their products, their operation guidelines hardly match the real thermal conditions. Present study overviews firefighter's fatalities and thermal conditions that firefighters and their equipments face. Lastly, thermal packaging methods that we have developed and tested are introduced.

• Journal of Korean Society of Environmental Engineers
• /
• v.31 no.1
• /
• pp.15-20
• /
• 2009

The concentration of residual chlorine should be kept at over 0.1 mg/L in the circular water tank used in a water purification system. Generally, the concentration of residual chlorine depends on the structure and the volume of water tank, and also the water flow rate. To secure the diffusion time is important to the concentration of residual chlorine. For that reason, the baffles are installed in the circular water tank. In the present study, the variations of water and chlorine concentration were obtained with time using the numerical analysis. And also, the streamlines were shown according to the number of baffles. As a results, the vortex flow appeared between baffles, and the diffusion time of chlorine increased with the more number of baffles.

• Journal of the Korean Solar Energy Society
• /
• v.33 no.3
• /
• pp.91-98
• /
• 2013

In this study, we have carried out development and performance evaluation of optimized MEMS(Multi-Effect-Multi-Stage) fresh water generator with $7m^2/day$ for solar thermal desalination system. The developed MEMS was composed of high temperature part and low temperature part. This arrangement has the advantage of increasing the availability of solar thermal energy. The MEMS consists of 2 steam generators, 5 evaporators, and 1 condenser. Tubes of heat exchanger used for steam generators, evaporators and condenser were manufactured by corrugated tubes. The performance of the MEMS was tested through in-door experiments, using an electric heater as heat source. The experimental conditions for each parameters were $20^{\circ}C$ for sea water inlet temperature to condenser, $8.16m^2$ /hour sea water inlet volume flow rate, $70^{\circ}C$ for hot water inlet temperature to generator of high temperature part, 3.6 4.8, 6.0 $m^2/hour$ for hot water inlet volume flow rate. As a result, The developed MEMS was required about 85 kW heating source to produce $7m^2/day$ of fresh water. It was analyzed that the performance ratio of MEMS was about 2.6.

• Journal of the Korea Institute of Building Construction
• /
• v.23 no.6
• /
• pp.863-873
• /
• 2023

This research explores the efficacy of safety vest colors at construction sites to enhance worker safety. Utilizing the Munsell color system and the Korean Standard Color Analysis program(KSCA), the study developed a prototype safety vest tailored to specific types of construction work. A safety vest with a color contrasting the site's environment significantly improves worker visibility and intuitiveness in identification, potentially reducing safety incidents. The study determined the optimal color specifications(hue, value, chroma) for safety vests in various construction roles, such as 10GY, 8, 8 for rebar placement, 8.75B, 7, 8 for Euroform, 3.75B, 2, 4 for Gangform, and 6.25BG, 5, 10 for steel erection. Feedback from construction experts on these prototypes, particularly regarding the safety vests for rebar placement and steel framework, was overwhelmingly positive(90% approval). Consequently, the proposed safety vest color scheme is deemed highly effective.

• Journal of Korean Society of Environmental Engineers
• /
• v.30 no.8
• /
• pp.839-846
• /
• 2008

The flocculation characteristics of polyacrylamide base flocculants were estimated to reduce the moisture content of the dehydrated cakes. The dewaterability for sewage sludge was found to have a marked effect depending on the flocculant type, agitating speed and time, kind of dissolution water, etc. The optimal agitating speed and time were 700 rpm and 3 sec, respectively, in this experimental condition. and the dewaterability was proportion to the agitating speed upto 700rpm. When recycle water as the dissolution water was used, the solution viscosity of all kind of flocculants was decreased. However, the change of its viscosity are not proportioned to the dewaterabilities for each flocculant. Flocculation system of combinations of the first and sencond flocculation using single flocculant was investigated. Effects of the ratio of first and second dosage for dual flocculation on the dewaterability were also investigated. The optimum conditions of dual flocculation system are 75% and 50% as first dosages for low and high viscous flocculant for total dosage of common flocculation, respectively. Based on the results, an overall mechanism of dual flocculation system is proposed and it is envisaged that optimization of flocculation processes in this way can result in considerable savings in cost.