• Fire Science and Engineering
• /
• v.25 no.2
• /
• pp.132-137
• /
• 2011

A relationship between resisting moment and the structure of an automatic closure device is introduced for analyzing the effect of opening and closing condition on various fire door sizes in the pressurized room for smoke control system. The larger the size of fire door is, the more force is required for reaching to opening and closing conditions and there exists the design range of fire door in the pressurized room reflecting the closing time of fire door, rotative velocity, a relation between rotative angle and force and the efficiency of the automatic closure device.

• Journal of the Korea Convergence Society
• /
• v.11 no.2
• /
• pp.155-160
• /
• 2020

In this study, the pleasant driving environment of the driver and passenger in the summer was investigated through the internal flow analysis of air due to the opening and closing of the car windows. The conditions on the entrance of the air conditioner with the opening and closing status of vehicle window were applied to the flow analysis by taking into consideration the actual driving environment. The automotive air conditioning outlet, the seat and the inside of car were modeled. As the air flow inside the car was analyzed, the air flow configuration and the temperature distribution were examined. In this analysis, the results were taken in consideration of only the effects of internal air and the opening and closing of window, assuming the interior of the vehicle as insulation. The analysis of each condition shows that these models maintain a pleasant environment. It is seen that this analysis result on the internal flow analysis according to the opening and closing of vehicle window can be applied by converging with the field of design.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.20 no.5
• /
• pp.528-534
• /
• 2011

This study analyzes thermal stress and durability fatigue on the modelling of EGR valve. In case of 10% opening at its inlet, the minimum temperature gets cool as 3 times as inlet temperature. The maximum equivalent stress becomes lowest as the value of $2.6274{\times}109$ Pa and fatigue life becomes highest as 23.657 Cycle. But the minimum temperature gets cool as 2.2 times as inlet temperature in case of 50% opening at its inlet. The equivalent stress becomes higher and fatigue life becomes lower than in case of 10% opening. In case of 100% opening at its inlet, the minimum temperature gets cool as 0.2 times as inlet temperature. The equivalent stress becomes lower and fatigue life becomes higher than in case of 50% opening. Maximum equivalent stress and total deformation are shown at the closing of EGR valve by the pressure of inflow gas. The structural analysis result of this study can be effectively utilized with the design of EGR valve by investigating prevention and durability against its damage.

• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.6
• /
• pp.1179-1186
• /
• 2012

For better understanding of carbon cycle dynamics of an agro-ecosystem, an accurate assessment of seasonal and daily $CO_2$ flux is essential to understand the relationship between various environmental factors and crop productivity. We developed the automatic sliding canopy chamber (ASCC) system that measured continuous net ecosystem productivity (NEP) over whole growing season under the natural meteorological rhythm. The ASCC was composed of two main parts which were sliding part for measuring NEP, and automatic opening and closing chamber (AOCC) for measuring soil respiration (SR) on the soil surface. The ASCC was developed by using open flow method for measuring soil $CO_2$ efflux. The disturbance of natural meteorological condition was minimized by opening the base frames. In the field test with barley (Hordeum vulgare L.), NEP was calculated at $140mg\;CO_2\;m^{-2}h^{-1}$ on a clear day using continuous data and eliminated the possibility of overestimate about 16% using one hour data during the day time. Unlike other small scale chamber system, installation on cropping-field made it possible to take any modifications which might be caused by natural environmental condition.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.15 no.6
• /
• pp.1839-1851
• /
• 1991

Fatigue crack behavior is studied through the two-level rotary bending test with the deep non-through radial holed notch specimens of low carbon steels(SM22C). The main factors investigated are the effects of the damage zone size around crack tip and phenomena of closing or opening of the crack tip. Obtained results are summarized as follows. Fatigue crack behavior in second level stressing slightly lower than fatigue limit is closely related to the size of damage zone produced by the first level stress higher than fatigue limit and to the phenomena of crack closing and opening for the second level stress. The non-propagating crack limit condition depends upon the crack length l$_{1}$ propagated under the first level stress and the magnitude of second level stress .sigma.$_{2}$ lower than the fatigue limit. The non-propagating crack limit condition is expressed by following eq. $\sigma_2^{6.1}{\times}l_{1}=7.35{\times}10^{6}[(kg_{f}mm^{6.1}(mm)]$

• Journal of radiological science and technology
• /
• v.42 no.6
• /
• pp.477-482
• /
• 2019

Recently, due to the increased use of medical radiation, the radiation exposure of radiation workers should be considered as well as medical exposure of patients. And it is recommended to close the door during radiography. however, In this study, when the door was inevitably opened for radiography, the proposed method was to install the shield as a method of reducing the exposure dose. And its efficiency was analyzed. In simple chest radiography, the measurement point was changed according to the measurement location. Dose rate were measured 10 times for each condition using a dosimeter. And the average value was derived. Using this, the change of dose according to the opening and closing of the door and the installation of the shield was analyzed. Using this, we compared and analyzed the dose change according to the door opening and closing and the installation of the shield, and significance was verified through the SPSS ver. 24. Depending on whether the door was opened or closed, 11,215.35%, 159.0%, 101.9% increased in front of the door in the consol room, behind the wall and behind the lead glass. Depending on the installing of the shield, the 49.2%, 29.6%, 19.9%, 30.6% decrease in front of the door in the examination and consol room, behind the wall and lead glass. In addition, statistical analysis was showed that there were significant differences in both the results according to whether the door was opened or closed and shielding(p<.05). Close the door during radiography. However, when the door should be opened, it was confirmed that the dose rate were reduced by installing the shield. Therefore, to optimize radiation protection, it is recommended to install shields when opening the door.

• Journal of the Korean Home Economics Association
• /
• v.41 no.10 s.188
• /
• pp.199-209
• /
• 2003

The purpose of this study was to investigate the causes of bankruptcy in small apparel stores. Data were collected from 153 apparel retail store owners who experienced failure in small apparel stores in Busan. The results showed as follows; The internal factors that caused bankruptcy in small apparel stores were the problems related with employees, capital, investment, weak marketing strategies, inadequate management, and characteristics of store owners. The external factors were economic condition, unexpected incidents, and the condition of market. There were significant differences in the perception of factors which caused the store bankruptcy according to prior business experience before opening apparel stores, the level of education, and the period between store opening and closing.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.8 no.4
• /
• pp.619-629
• /
• 2013

This study was conducted to compare the effect improving balance abilities of 3 balance training programs by randomized intervention trial. Study subjects were 29 female students recruited from a university in Gwanju, who allocated randomly to 3 intervention groups, aqua group(modified Halliwick 10 point program, N=10), visual bio-feedback balance training group(N=10), and balance-pad plus trampolin group(N=9). As the results of repeated musure ANOVA, Wilcoxon signed rank test, major research findings were as follows; 1. Regarding SI or BIEMG measured at upright posture on hard platform, bio-feedback group under the condition with opening both eye and aqua group under the condition with closing both eye showed signigicant improvement in balance ability, respectively. 2. Regarding SI or BIEMG measured at upright posture on soft platform, bio-feedback group under the condition with opening both eye and aqua group under the condition with closing both eye showed signigicant improvement in balance ability, respectively. 3. Regarding all 3 sensory ratios, bio-feedback group showed significantly higher increasement in them than other 2 groups. The results suggested that visual bio-feedback training program improve the all 3 sensory functions required for balancing, and aqua training modified from Halliwick 10 point program contribute to improve vestibular function principally.

• 한국전산유체공학회:학술대회논문집
• /
• 2007.10a
• /
• pp.272-276
• /
• 2007

In this paper, we researched a parametric study in flow control system using louver with numerical method. Generally, for the large fans with constant rotational speed, the louver can be used to control the flow rate. The opening and closing of louver can make a some change of flow properties generated by a large fan. To develope the relation between the opening angle of louver and flow rate(or pressure difference), we simulated the flow past the modelled louver installed in a virtual wind tunnel. For the various angles, the mean flow properties are investigated and parameterized with a given boundary condition. The research result can be used directly to design the flow control system of large constant-speed fans, which are often applied to petrolic refinery system.

• Journal of Korean Medical classics
• /
• v.13 no.1
• /
• pp.74-101
• /
• 2000

Geungyul(根結) means roots and nodes of meridians. If human body gets damaged by energy which each seasons has, the meridians get some troubles. Healing for symptom, meridians consist of root, stay, follow, inpouring and node of acupuncture points should be in harmony. 1. This chapter explain roots and node parts of each meridian, acupuncture points name and root, stay, follow, inpouring of acupuncture points which in arm and leg of three Yin and Yang. 2. The opening, closing, axis function, the symptom, and the needling of both meridians of Yin and Yang are explained. 3. The method that predicts the rise-and-fall of visceral energy and the time of death by using an order of pulse and intermittent pulse is explained. 4. It is explained that since the physical condition of the rich and the poor are different, the method using a needling for each person to be healed, such as the deep-and-shallow and the quick-and-slow, are different. 5. It is explained that the excess and the deficiency in the energy of shape should be considered when a acupuncture is given.