• Tunnel and Underground Space
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• v.26 no.5
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• pp.375-383
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• 2016

High-speed trains have been developed widely in many countries in order to transport a large quantity of people and commodities rapidly. When a high speed train enters a tunnel, aerodynamic resistance is generated suddenly. This resistance causes micro pressure wave and discomfort to passengers. Therefore, it is essential to incorporate a pressure relief system in a tunnel and streamlined shape of a train in order to reduce aerodynamic resistance caused by a high-speed train. Additionally, the cross-sectional area of a tunnel should be carefully determined to reduce discomfort of passengers. A pressure relief duct and a vertical shaft are representative measures in a tunnel. This study represents the effect of pressure relief ducts in order to alleviate pressure changes within a time period in a tunnel. One-dimensional network numerical simulations were carried out in order to estimate the effect of pressure relief systems.

• Journal of Welding and Joining
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• v.14 no.3
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• pp.48-57
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• 1996

A study was made to examine the characteristics of base metal and stress relief cracking(SRC) of heat affected zone(HAZ) for HY-100 and Cu-bearing HSLA-100 steels. The Gleeble thermal/mechanical simulator was used to simulate the SRC/HAZ. The details of mechanical properties of base plate and SRC tested specimens were studied by impact test, optical microscopy and scanning electron microscopy. The specimens were aged at $650^{\circ}C$ for HSLA-100 steel and at $660^{\circ}C$ for HY-100 steel and thermal cycled from $1350^{\circ}C$ to $25^{\circ}C$ with a cooling time of $\Delta$t_${800^{circ}C/500^{circ}C}$=21sec. corresponds to the heat input of 30kJ/cm. The thermal cycled specimens were stressed to a predetermined level of 248~600MPa and then reheated to the stress relief temperatures of $570~620^{\circ}C$. The time to failure$(t_f)$ at a given stress level was used as a measure of SRC susceptibility. The strength, elongation and impact toughness of base plate were greater in HSLA-100 steel than in HY-100 steel. The time to failure was decreased with increasing temperature and/or stress. HSLA-100 steel was more susceptible to stress relief cracking than HY-100 steel under same conditions. It is thought to be resulted from the precipitation of $\varepsilon$-Cu phase by dynamic self diffusion of solute atoms. By the precipitation of $\varepsilon$-Cu phase, the differential strengthening of grain interior relative to grain boundary may be greater in the Cu-bearing HSLA-100 steel than in HY-100 steel. Therefore, greater strain concentration at grain boundary of HSLA-100 steel results in the increased SRC susceptibility. The activation energies for SRC of HSLA-100 steel are 103.9kcal/mal for 387MPa and 87.6kcal/mol for 437MPa and that of HY-100 steel is 129.2kcal/mol for 437MPa.

• Tunnel and Underground Space
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• v.28 no.3
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• pp.247-257
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• 2018

High-speed trains have been developed widely in many countries in order to transport large quantity of people and commodities rapidly. When a high speed train enters a tunnel, aerodynamic resistance is generated suddenly. The resistance caused from air pressure induces micro pressure wave and discomfort to passengers in a train. Therefore, a pressure relief system should be installed in a tunnel to reduce the resistance acting against the running train in a tunnel. Additionally, the shape of a grain should be streamlined in order to reduce aerodynamic resistance caused by a high-speed train. The cross-section of a tunnel also should be carefully designed to reduce discomfort of passengers. This study represents the effect of pressure relief ducts installed between two running tunnels. The pressure relief duct was integrated with a cross-passage in order to save cost and construction time. One-dimensional network numerical simulations were carried out in order to estimate the effect of pressure relief systems.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.1899-1902
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• 2003

Recently several methods have been developed for the virtual space construction. Generally, most of the methods are geometric-based rendering technic, but they are difficult to construct real-time rendering because of large data. In this paper, we present a three dimension image-based rendering method that enable a constant speed of real-time rendering regardless of object complexity in virtual space. The Proposed method shows good performance for the virtual space construction with high complexity.

• Journal of architectural history
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• v.20 no.4
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• pp.135-156
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• 2011

Stupa in India divides into two: stupa in flatland temple with a character of tomb, and devotional stupa made for offering. The difference of such character is made by whether there is any Sari, and main center for worship is flatland stupa where Sari is settled. Stupa in flatland temple is targeted to that with Sari, whose character is applied into Relief-stupa. The characteristics of Relief-stupa can be divided into two: a relief with similar type of flatland stupa in the form, and a devotional relief in which drum and upper part of tower are developed. The Relief-stupa of flatland temple could be confirmed at tower gate of Sanchi tower, decoration of handrail, and the wall attached to Amaravati and Nagarjunakonda stupa. To the contrary, drum and upper wheel part in the Relief-stupa are developed in the votive stupa. Such characteristics had different features according to usage: The example of former is that there is an expression of landscape of stupa built at that time, and the example of latter is those which had similar type of stone cave temple or offering tower near stupa. Thus, the meaning is subject to the existing of Sari. Stupa building developed along with the development of Buddhist structural activity with the existing popular tradition. And its influence was expanded along with various cultures locally. And, the structure and tower reflected various types and thoughts. Stupa reflected its building site and method according to types, and was created in a new form by its usage.

• Journal of the East Asian Society of Dietary Life
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• v.2 no.1
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• pp.35-56
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• 1992

This paper has made a close examination of Shingan Goohwang Chowalyo(1660), Cheesaeng yoram(1691), Sallim Gyungjae(1715) and Imwon simyook Jee(1827), to grasp what kinds of famine relief foods have been analyzed in terms of nutrition elements and cooking methods. And also this paper has surveyed the changes of these famine relief foods according to the times. Three hundred forty one famine relief foods are recorded in the above mentioned books, Among them, ten foods are recorded in common in these four books: pine needles, elm tree skin, soybeans, wax, jujubes, black beans, glutinous millet, turnip seeds white pine-mushroons and Chool-Atractylodes japonica. The methods of cooking and processing are most varied in the order of pine needles, black beans and elm tree skin, Pine needles are rich in protein and fat, and so may be regarded as the first of famine relief foods. Elm tree skin is of more than 50% carbohydrate and may be used in plate of cereals. I addition to these, Hwangui-milk vetch, Choonsu-cedrela Sinensis, Tacksa-Alisma Orientale Juzep and some other foods contain starch, glucose, fatty acids, and amino acids. So they may be used for replacing cereals and relieving famine. Before these famine relief foods are cooked or processed, according to their ingredients they should be soaked in water for a time in some cases the water should be changed several times. In Shingan Goohwang Chowalyo and Cheesaeng Yoram, measuring units are rarely recorded, while in sallim Gyungjae, they are explicitly shown. Imwon Simyook Jee clearly shows the use of oriental medicine materials. And the fur above mentioned books show no record of famine relief animal foods. To these days, vegetables have been boiled, squeezed and seasoned with salt and oil, but the better the economic conditions become, the less other famine relief foods are used. Nevertheless it is expected that these natural foods can be made favorite dishes with the best use of their good flavors and tastes.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.685-690
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• 2000

In this study relationship between relief angles and chatter vibration in turning was examined by using the direct cutting test, in which the cutting depth of a tapered workpiece is varied continuously and the limiting depth of cut is measured at the time when chatter occurs. Test results reveal that 1) limiting depth of cut increases is proportion to side relief angles between 0$^{\circ}$ and 3$^{\circ}$, 2) limiting depth of cut does not show any evident change in spite of side relief angle increased from 3$^{\circ}$ to 12$^{\circ}$, 3) also limiting depth of cut does not change despite front angle change from 0$^{\circ}$ to 12$^{\circ}$.

• The Journal of Internal Korean Medicine
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• v.44 no.4
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• pp.675-702
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• 2023

Objective: This study assessed the effectiveness of using Yijung-tang to treat chronic gastritis through a systematic review and meta-analysis of randomized controlled trials (RCTs). Methods: The search was conducted using keywords such as "gastritis", "Lizhong", "Yijung", and "Chronic gastritis" on July 31, 2023. A meta-analysis was conducted according to outcome measurements, such as total effective rate (TER), Traditional chinese medicine symptom score (TSS), gastric hormones, and symptom relief time, using the Review Manager website. Results: A total of 11 RCT studies were selected. The treatment group (Yijung-tang-gagam or Yijung-tang-gagam+Western medicine) showed significant improvement effects in terms of TER, TSS, serum gastrointestinal hormones (motilin (MTL), gastrin (GAS), and somatostatin (SS)), and symptom relief time compared to the control group (Western medicine). TER-RR : 1.20, 95% CI : 1.11 to 1.30, P≤0.00001, RR : 1.21, 95% CI : 1.14 to 1.28, P≤0.00001; MTL-MD : 35.99, 95% CI : 30.79 to 41.20, P≤0.00001); GAS-MD : 103.33, 95% CI : 97.62 to 109.04, P≤0.00001); SS : MD : -37.19, 95% CI : -41.75 to -32.64, P≤0.00001; symptom relief time (nausea)-MD : -1.96, 95% CI : -2.47 to -1.45, P≤0.00001; symptom relief time (colic)-MD : -1.75, 95% CI : -2.31 to -1.18, P≤0.00001. Conclusion: This study suggests that Yijung-tang is effective against chronic gastritis. However, the number of studies was insufficient, and the diagnosis and evaluation criteria were not standardized. Furthermore, because of the low quality of the included studies, more clinical studies need to be conducted to increase the possibility of clinical use.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.892-897
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• 2000

In this study, tap wear was analyzed not only to predict the tap life time but also to propose an improved tap design. Because rake angle and thread relief of tap are the significant factors in geometry of tap, these two factors were picked as the experiment variables. The experiment was conducted with six types of tap which have 6$^{\circ}$ , 8$^{\circ}$ and 12$^{\circ}$ of rake angles with 0,08mm and 0.14 mm of thread relief. From the measured cutting force, it could be known that cutting torque was low at the large the rake thread relief and tool life was long as rake angle became large. Eventually, tool life is longest when rake angle is 12$^{\circ}$ and the with 0.08mm thread relief. Aand the width of crater wear and that of flank wear were measured when a tapping torque was 20 [$kg_f$-mm] . Most of the measured values were above the width of tool wear[$V_B$=O.O3m], which means that tool life is over.

• Aerospace Engineering and Technology
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• v.11 no.2
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• pp.109-116
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• 2012

A vent-relief valve performs as a safety-valve assembly for liquid propellant feeding system of space launch vehicle, which relives pressurant propellant tanks during the filling and the flight. At vent mode, valve is opened and closed by driving pneumatic pressure, and at relief mode, valve is automatically operated to set relief pressure. In this study, we have analyzed a basic layout of vent-relief valve which is designed using foreign LVs(Saturn) to satisfy requirements of Korean Space Launch Vehicle. The simulation model of vent-relief valve is designed by using the AMESim code to verify design parameters and evaluate pneumatic behaviors of valve. In this study, we performed dynamic characteristic simulations on design parameters. And we could predict opening/closing time and pressures, operating performances on design parameters. Using this results, we could suggest detail design and boundary conditions of design.