• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.32 no.1C
• /
• pp.27-35
• /
• 2012

The relieving platform has the advantage of decreasing the total lateral earth pressure on the retaining wall and increasing the overall stability of the structure. Several modeling tests were performed to determine the earth pressure distribution on the retaining wall with a relieving platform and to compare it with that of the cantilever retaining wall. Different types of soil and angle of cutting surface were used to determine the effect of the soil characteristics and the backfill conditions on these earth pressure distributions. From the modeling tests, comparisons between the retaining wall with a relieving platform and the cantilever retaining wall show that the reduction of the lateral earth pressure and deformation of wall was indicated clearly on the retaining wall with a relieving platform. And the overall stability was increased by the relieving platform.

• Food Science of Animal Resources
• /
• v.24 no.1
• /
• pp.73-79
• /
• 2004

Functional properties of farm-grown pheasant meat with different sex, age and cutting portion were investigated, and the textural and sensory characteristics of processed products were also evaluated. Chemical composition of pheasant meat was characterized to be high in protein and low in fat, and breast muscle showed more protein and less moisture than thigh muscle. Moisture/protein ratio of the pheasant meat was relatively low in a range of 2.82∼3.40, indicating the pheasant meat would be a good source of processed meat, and it had high water holding capacity and myofibrillar protein extractability with some variations depending on age and portion cut(p<0.05). Thigh muscle showed higher value of L＊ and b＊ and lower value of a＊ than breast muscle. However, no difference was observed in color of meat with different age and sex. The meat from the 6 months and the breast cut had lower shear force than those of respective 17 months and the thigh regardless of sex. The pressed ham and sausage manufactured with the pheasant meat had better score than the commercial products manufactured with pork or chicken in sensory and textural parameters.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• v.10 no.1
• /
• pp.107-119
• /
• 2006

Recently with developments of an internet and web techniques, the amount of data that are stored in database is increasing rapidly. So the range of adaption in database has been expanded and a research of Data Mining techniques finding useful skills from the huge database has been progressed. Many original algorithms have been developed by cutting down the item set and the size of database isn't required in the entire course of creating frequent item sets. Although those skills could save time in some course, it requires too much time for adapting those techniques in other courses. In this paper, an algorithm is proposed. In an Transaction Database that the length of it's transactions are short or the number of items are relatively small, this algorithm scans a database once by using a Hashing Technique and at the same time, stores all parts of the set, can be appeared at each transaction, in an Hash-table. So without an influence of n minimum percentage of support, it can discover a set of frequent items in more shorter time than the time what is used by an original algorithm.

• Journal of Environmental Impact Assessment
• /
• v.13 no.6
• /
• pp.295-305
• /
• 2004

After the Rio declaration on environment and development in 1992, developed countries are undertaking "environmentally sustainable transportation (EST)" projects. To meet the needs for EST, current transportation policies in Korea are rapidly reforming and one of its concerns is modernizing and upgrading railway freight system. Planning new railroad construction projects is increasing and subsequent environmental impact assessment (EIA) demands improvements, especially in both the EIA and decision making systems. In this paper, we discuss the present status of EIA for railroad construction projects, especially, by analyzing the EIA documents for the last six years. The EIA for railroad construction projects accounts for only 4.9% of total 918 project EIAs during 1998-2003, and the portion is gradually increasing. Major environmental concerns for EIA in railroad construction projects were geomorphological and ecological changes, protection of rare organisms, air pollution, water pollution, waste management, and noise, etc. We compared characteristics of environmental impacts of railroad construction with those of vehicle road construction, based on environmental and construction-planning indicators appeared in Environmental Impact Statements. Railroad construction usually requires longer tunnels and bridges for a given length than those for vehicle road construction. In addition, the amounts of geomorphological and ecological changes (road-cutting, embankment, devegetation, etc.) in railroad construction were generally less than 50% of those in vehicle road construction. To develop environmentally friendly railway systems, monitoring studies for environmental impacts of railroads such as habitat fragmentation and road kills, dispersal of alien plants, tunnelling effects on groundwater and vegetation, and noise impacts are highly recommended.

• Proceedings of the KSPS conference
• /
• 1996.10a
• /
• pp.521-528
• /
• 1996

This presentation explores on the perceptual characteristics of the lateral sound /l/ in CV syllables. At initial position we found that /l/ has well marked formant transitions. Then several questions arise: 1) are these formant structures dependent on the following vowel\ulcorner. 2) Are the formant transitions giving an additional cue for the identification\ulcorner Considering that the French vocalic system presents a greater variety of vowels than Spanish, several experiments were designed to verify to what extent a more extensive range of vocalic timbres contribute to the perception of /l/. Natural emissions of /l/ produced in Argentine Spanish and Canadian French CV syllables were recorded, where V was successively /i, e, a, o, u/ for Spanish and /i, e, $\varepsilon$, a, $\alpha$, o, u, y, \phi$/ for French. For each item, the segment C was maintained and V was replaced by cutting & splicing by each of the remaining vowels without transitions. Results of the identification tests for Spanish show that natural /l/ segments with low Fl and high formants F3, F4 can be clearly identified in the /i, e, u/ vowel contexts without transitions. For French subjects the combination of /l/ with a vowel without transitions reflected correct identifications for its own original vowel context in /e, $\varepsilon$, y, $\phi$/. For both languages, in all these combinations, F1 values remained rather steady along the syllable. In the case of /o, u/ very likely the F2 difference lead to a variety of perceptions of the original /l/. For example in Ilul, French subjects reported some identifications of /l/ as a vowel, mainly /y/. Our observations reinforce the importance of F1 as a relevant cue for /l/, and the incidence of the relative distance between formants frequencies of both components.

• Journal of the Korean Society for Precision Engineering
• /
• v.30 no.12
• /
• pp.1303-1312
• /
• 2013

We report an ultra-precision lathe designed to machine micron-scale features on a large-area roll mold. The lathe can machine rolls up to 600 mm in diameter and 2,500 mm in length. All axes use hydrostatic oil bearings to exploit the high-precision, stiffness, and damping characteristics. The headstock spindle and rotary tooling table are driven by frameless direct drive motors, while coreless linear motors are used for the two linear axes. Finite element method modeling reveals that the effects of structural deformation on the machining accuracy are less than $1{\mu}m$. The results of thermal testing show that the maximum temperature rise at the spindle outer surface is approximately $0.5^{\circ}C$. Finally, performance evaluations of the error motion, micro-positioning capability, and fine-pitch machining demonstrate that the lathe is capable of producing optical-quality surfaces with micron-scale patterns with feature sizes as small as $20{\mu}m$ on a large-area roll mold.

• Journal of architectural history
• /
• v.23 no.5
• /
• pp.47-60
• /
• 2014

Urban-Hanok emerged as a result of urbanization of Hanok in the modern period. In particular, Urban-Hanok has been mass-produced from the early 1920s, when the population is concentrated in cities, until the middle. Large-scale development by the professional developer has been developed in large-scale land rather than individual client because housing shortage was serious problem. 11 Gahoe-dong was made in 1935-36 is representative Urban-hanok area of Bukchon. It was formed through division of large-scale Land in 1930's. In the 1930's, the large-scale development projects of Urban-Hanok was triggered by the two events. One is Land Investigation Project performed by the Japanese government to capitalization of property, another is the pro-japanese bought the large scale-land in Gahoe-dong at bargain price from The Japanese government. Each lot has still a topographical characteristics such as land-dividing quality, the way of development, characteristic quality of urban-tissue. 11 Gahoe-dong, Urban-hanok area was developed two ways. First, development have been adapted to the topography. The lots have reflected topographical conditions such as land cutting area, a retaining wall, land-diving was maintaining the original topography almost. Second, it was street oriented development. The lots have developed sequentially along the street. So, the lots's shape and size is different each. For this reason, this area distribute various type of Hanok.

• The Korean Journal of Ecology
• /
• v.23 no.5
• /
• pp.377-382
• /
• 2000

Picea abies plantation in Mt. Eifel, Germany was studied phytosociologically, with special reference to species composition, structure, ecology and dormancy form, comparing to those of Fagus sylvastica population that once dominated the P. abies plantation. Thirteen plant species appeared on average. According to their ecological distribution, they were classified into three groups, F sylvastica forests, natural coniferous forests and bare-land after clear-cutting. In Luzulo-Fagetum population, Luzula luzuloides was the dominated species while in P. abies plantation was dominated by Avenella flesuosa. In assessment of herbaceous plants by indicator species of Ellenberg, increasing number of shade-intolerant species and acid-tolerant species occurred. In analysis of plant dormancy form, species of Chamaephytes, Phanerophytes and Hemikryptophytes increased, while that of Geophytes decreased. As a result, we found P. abies plantation unstable in ecological aspects.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2001.03a
• /
• pp.199-206
• /
• 2001

Landslides generally occur due to influences of the internal and external factors. Internal factors include ground characteristics, terrain and so on. External factors can also be divided into natural factors such as rainfall, ground water, earthquake and so on, and artificial factors resulting from cutting and embankments. Among these factors, rainfall becomes the most important external factors by means of which landslides occur in Korea. To appropriately deal with tile effects of pore water pressures due to rainfall, the method using the pore water pressure ratio(r$\_$u/) is generally applied in slope stability analysis or the design of slope reinforcements. Since tire value of r,, is in general not constant over the whole cross section, in most slope stability analyses the average values are used with little loss in accuracy. However, determination of the average values of r$\_$u/ to applied in the design is difficult problem. Therefore, in this study, tile average values of r$\_$u/ according to the intensity of rainfall and slope inclination is suggested based on results of the small scaled model tests using the artificial rainfall apparatus. It is found from the model tests that the average values of r$\_$u/ is about 0.07∼0.18(in case of the intensity of rainfall is 50mm/hr.), about 0.10∼0.28(in case of the intensity of rainfall is 100mm/hr.), and about 0.10∼0.33(in case of the intensity of rainfall is 150mm/hr.).

• Journal of the Korean Society of Safety
• /
• v.15 no.1
• /
• pp.72-79
• /
• 2000

In recent, occupational diseases in harmful working places become a social issue. It is the well-known fact that a respiration in polluted working places exert a serious effect on health of workers. Accordingly, the cutting off contaminants air originally is the best way to improve working environments. In these cases, ventilation systems should be essentially installed to dilute or exhaust the contaminated indoor air. In this study, we investigated the characteristics of ventilation system of the noxious gas in working indoor places with natural ventilation by using COMET. The numerical simulations were carried out the natural ventilation with two phase(air, dust). For turbulent flow, Reynolds stresses were closed by the standard $\kappa$-$\varepsilon$ model. The results are as follows ; 1) In the natural exhaust in the working place, the flows of the central region have a more rapid velocity vector than the right and left one. 2) Numerical results show that the distribution of contaminants concentration have greater influence on convection than the case of diffusion by government of velocity vectors. 3) To observe the velocity variation with distance, three location of distance are considered. As results, it shows that the velocity are 0.075(m/s) at y=5(m), 10(m) and mean concentration are raised 10.6% at y=5(m), 10(m). 4) We have presented the useful data for the adequate counterplan in the harmful working places by carrying out the various investigation of the natural ventilation.