• Journal of Animal Environmental Science
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• v.10 no.1
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• pp.23-28
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• 2004

This study was conducted to improve a ventilation system on the enclosed farrowing-nursery pig house in Korean swine facilities. This survey ventilation system types four major structures. The first structure has planer slot inlet, where air comes in, and these are placed outside the wall under the eave. Then the air from the pig house flows out through the chimney outlet operated by an exhaust fan(V1). The second structure has an air input through the perforated ceiling inlet, then the air from the pig house flows out through the chimney outlet operated by an exhaust fan(V2). Through the circular duct inlet placed inside the juncture of the entry wall, air also comes in(third structure). Then, air from the pig house flows out through the chimney outlet operated by an exhaust fan(V3), Similarly, air comes in through the circular duct inlet placed inside the juncture of the entry wall, but air from the pig house flows out through the side wall by an exhaust fan(V4). Temperature, relative humidity, air velocity and ammonia concentration(NH$_3$) were measured in the interior farrowing-nursery pig house during winter. The results were as follows; Interior temperature at the pig house was not remarkably different in all ventilation systems. The V4 system had low area air velocity, and this was better than other systems. It also had a lower ammonia concentration than other systems. V3 and V4 systems had stable airflow patterns, better than other systems. Therefore, it is suggested that the V3 and V4 ventilation system be applied in the enclosed farrowing-nursery pig house in winter.

• Explosives and Blasting
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• v.41 no.3
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• pp.62-72
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• 2023

The aging of plant structures due to industrialization in the 1970s has increased the demand for blast demolition. While blasting can reduce exposure to environmental pollution by shortening the demolition period, improper blasting design and construction plans pose significant safety risks. Thus, it is vital to consider optimal blasting demolition conditions and other factors through collapse behavior simulation. This study utilizes a 3-D combined finite-discrete element method (FDEM) code-based 3-D DFPA to simulate the collapse of a chimney structure in a thermal power plant in Seocheon, South Korea. The collapse behavior from the numerical simulation is compared to the actual structure collapse, and the numerical simulation result presents good agreement with the actual building demolition. Additionally, various numerical simulations have been conducted on the chimney models to analyze the impact of the duct size in the pre-weakening area. The no-duct, duct, and double-area duct models were compared in terms of crack pattern and history of Z-axis displacement. The findings show that the elapse-time for demolition decreases as the area of the duct increases, causing collapse to occur quickly by increasing the load-bearing area.

• International Journal of High-Rise Buildings
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• v.11 no.4
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• pp.277-286
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• 2022

In this study, The POD technique was applied to the fluctuating wind pressure of high aspect ratio circular cylinder to consider about its organizational structure, and considered about the characteristics of the fluctuating wind force obtained by synthesized the POD modes.

• 한국전산유체공학회:학술대회논문집
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• 2004.10a
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• pp.151-154
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• 2004

The HANARO, a multi-purpose research reactor of 30 MWth open-tank-in-pool type, has been under normal operation since its initial criticality in February, 1995. Many experiments should be safely performed to activate the utilization of the HANARO. A flow simulated test facility has been developed for the verification of structural integrity of those experimental facilities prior to loading In the HANARO. This test facility is composed of three major parts; a half-core structure assembly, flow circulation system and support system. The half-core structure assembly is composed of plenum, grid plate, core channel with flow tubes, chimney and dummy pool. The flow channels are to be filled with flow orifices to simulate similar flow characteristics to the HANARO. This paper describes an analysis of the flow distribution of the cote channel and compares with the test results. As results, the analysis showed similar flow characteristics compared with those in the test results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.276-284
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• 2019

Seismic research on bridges, dams and nuclear power plants, which are infrastructure in Korea, has been carried out since early on, but in the case of structures in thermal power plants, research is insufficient. In this study, a total of 192 dynamic analyzes were performed for 16 actual seismic waves and 12 PGAs. As a result, the probability of failure increased as the PGA value increased for each applied seismic wave, but it was different for each seismic wave. As a result, at 0.22G, the ratio of the compressive limit reached to the limit state was 25% and the ratio of the relative displacement reached the limit state was 13%. So, the probability of collapse due to compressive failure Is higher. Therefore, the fragility curve of the chimney which is the subject of this study can be used as a quantitative basis to determine the limit state of the target structure when an earthquake occurs and to be used for the safety design of the thermal power plants.

• Earthquakes and Structures
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• v.4 no.1
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• pp.11-39
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• 2013

Since slender structures such as utility poles, radio masts, and chimneys, are essentially statically determinate structures, they often collapse during earthquakes. Although vibration control is the most logical method for improving the earthquake resistance of such structures, there are many practical problems with its implementation due to their very long natural vibration period. This paper proposes a new vibration control device to effectively prevent the collapse of slender structures subjected to strong earthquakes. The device consists of a pendulum, an elastic restraint and a lever, and is designed such that when it is attached to a slender structure, the second vibration mode of the structure corresponds to the first vibration mode of the same structure without the device attached. This is highly effective in causing the transverse motions of the device and the structure to oppose each other and so reduce the overall transverse vibration during an earthquake. In the present paper, the effectiveness of the vibration control device is first evaluated based on laboratory experiments and numerical studies. An example of applying the device to a tall chimney is then simulated. A new dynamic analytical method for slender structures with abrupt rigidity variations is then proposed.

• Journal of architectural history
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• v.3 no.1
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• pp.101-122
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• 1994

This paper is one of the sequels from 'A Survey of Villages and Dwellings of Korean Immigrants in the North-Eastern Part of China'. It is the result of the extensive survey of Ch'ang-ts'ai-tsun village and covers several architectural characteristics of the dwellings. This paper alma to identify the 'double file' dwelling type, which is believed as one of the main stream of Korean folk dwelling. In this type, 'Chung-ju-kan' forms the central open space, where main household functions are carried out. This type originates from climatic reasons and functional reasons as well. This paper also aims to clarify how the dwelling forms are changed according to the life styles of various periods. The Korean immigrants in this village have experienced rapid changes in modern times like other Chinese. Through various political movements, the original dwelling type of this village has changed to adapt various needs and functions, which shows the simple truth : dwelling form changes according to the changes of life style and social structure. In this paper the directions of chimney through various periods are analyzed to verify the differences of the house layout methods and concepts of the time. The village had grown through 3 main periods before liberation period(1946), communization period(1946 - 1966) and contemporary period (1967 - ). It is concluded as follows: 1. The village was originated in late 19th century along the east-west street, which was a major routes of Korean Immigrants to China. In this area there was no regularity in its site plan. The direction of chimney, which was usually westward, was not determined according to the location of gate. This type was kept until liberization of this area, 1946. The plans of dwellings followed Ham-kyong-do 'double file' dwelling type, '6-kan dwelling' or '8-kan dwelling'. 2. The 'New Village' area, which was formed in the communization period, has a strict regularity in its site plan. The direction of chimney was determined as opposite direction of the gate. This method was maintained until 1976, when Mao died and new 'open' policy was held by Chinese government. In this area the 'dwelling house' plan type was not changed, but its layout and size were restricted. The general form of the dwelling in this village was shaped in this period. 3. The contemporary dwellings were built in random site location. The dwelling type was changed because of the reduction of family size and the permissin of private ownership. The number of rooms was reduced but the storage rooms and domestic animal hutches were added. But the 'Chung-ju-kan', the major chacteristics of north-eastern Korea dwelling is still kept. It becomes one large 'Chtin-ju-kan' room like 'open plan' type.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.6 no.1
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• pp.35-41
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• 1986

A hybrid modelling technique of a soil-structure system on viscoelastic soil medium is studied in this paper. The hybrid model consists of a near-field and a far-field with their common interface passing through the soil region at some distance from the base of the structure. It makes use of frequency-dependent impedances so as to represent the semi-infinite far-field. The far-field impedances are formulate including the radiation damping characteristics as well as the viscoelastic properties of the soil medium. The verification of the method has been carried out using a rigid circular plate on a viscoelastic half-space. The impedances obtained by the method are compared with the theoretical values. Example analyses have been performed for a tall chimney and the results have been compared with those obtained by other methods which are frequently used.

• Journal of the Korean Home Economics Association
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• v.17 no.2
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• pp.49-56
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• 1979

In Korean housing designs reflect uniqueness as a result of the influence of regional and atmospheric factors. In this regard, the early use of the hot floor (ondol) system is of special significance. This system is still in use today, not only for house-heating purposes in the homes of commoners, but also for cooking in the kitchen. The present study represents an investigation of the ondol structure since its earliest known usage. Methodology involves a documentary examination of the system. In point of time, this begins with the system's earliest usage and proceeds chronnologically down to the end of the Yi Dynasty. Research indicates that something very much like the ondol system appeared in the early tribal society of Mahan and its usage continued in the state of Koguryo (during the Three Kingdoms Period) in the homes of the poor. This unique system which had its origin in cold northern areas was utilized on a much broader basis during the Koryo Dynasty. Coming down to the Yi Dynasty it found acceptance and application in all parts of the peninsula. Variations in major component parts of the structure, such as the fuel hole, the flue, the draft , and the chimney, normally reflect regional dissimilarities. It is perhaps most significant that here-in contrast to other devices we have a system that serves concurrently for both heating and cooking purposes.

• Geomechanics and Engineering
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• v.1 no.3
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• pp.193-204
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• 2009

A 10.4-m high highway embankment retained behind mechanically stabilized earth (MSE) walls is under construction in the northeastern part of the Indian state of Bihar. The structure is constructed with compacted, micaceous, grey, silty sand, reinforced with polyester (PET) geogrids, and faced with reinforced cement concrete fascia panels. The connections between the fascia panels and the geogrids failed on several occasions during the monsoon seasons of 2007 and 2008 following episodes of heavy rainfall, when the embankment was still under construction. However, during these incidents the MSE embankment itself remained by and large stable and the collateral damages were minimal. The observational data during these incidents presented an opportunity to develop and calibrate a simple procedure for estimating rainfall induced pore water pressure development within MSE embankments constructed with backfill materials that do not allow unimpeded seepage. A simple analytical finite element model was developed for the purpose. The modeling results were found to agree with the observational and meteorological records from the site. These results also indicated that the threshold rainwater infiltration flux needed for the development of pore water pressure within an MSE embankment is a monotonically increasing function of the hydraulic conductivity of backfill. Specifically for the MSE embankment upon which this study is based, the analytical results indicated that the instabilities could have been avoided by having in place a chimney drain immediately behind the fascia panels.