• Title/Summary/Keyword: Smooth area

Search Result 468, Processing Time 0.027 seconds

A Study of CM(Construction Management) application method for exhibition facilities. (전시시설 건립을 위한 CM 적용방법에 관한 연구)

  • 문종승;임채진
    • Proceedings of the Korean Institute of Interior Design Conference
    • /
    • 2001.05a
    • /
    • pp.39-44
    • /
    • 2001
  • An instance of domestic exhibition facility building case, the shortage of managing personal in construction resulted serious issue on expenses, times, quality, and safty with no satisfaction on its process and result. According to subject's speciality the CM's application methods are varied and because of its speciality, overall process of building an exhibition facility operating by its owner. This study intends to exam a application possibility of CM on exhibition facility construction to make smooth communication among varied area that following to exhibition facility construction.

  • PDF

A Study on the Deadbeat Response Attribute of Nonlinear Systems (비선형시스템의 데드비트응답 특성 연구)

  • Song, Ja-Youn
    • Proceedings of the KIEE Conference
    • /
    • 2001.07d
    • /
    • pp.1993-1995
    • /
    • 2001
  • The subject of nonlinear control is an important area of automatic control. The behavior of nonlinear systems is much more complex. If the operating range of a control system is small, and if the involved nonlinearities are smooth, then the control system may be resonably approximated by a set of linear differential equations. This paper presents the deadbeat response attribute of some nonlinear systems, e.g., magnetic levitation, pendulum, van der pol oscillator etc.. The studied results through the computer simulation are shown a promising attribute of deadbeat response that the outputs of the systems are reached relatively fast the steady state.

  • PDF

Determination of dynamic stiffness for materials used under floating floors in dwellings (거주공간에서 뜬바닥 구조에 사용하는 동탄성계수 측정방법)

  • G. C. Jeong;Y. K. Oh;Kim, S. W.
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2002.11a
    • /
    • pp.392.1-392
    • /
    • 2002
  • This part of specifies the method for determining the dynamic stiffness of resilient materials used under floating floors. Dynamic stillness is one of the parameters that determine the sound insulation of such floors in dwellings. This part applies to the determination of dynamic stiffness per unit area of resilient materials with smooth surfaces used in a continuous layer under floating floors in dwellings.

  • PDF

Present Status and Future Prospect of Environment Agriculture in Daeho Reclain ed Saline Area (대호간척지의 환경농업 추진현황과 발전방향)

  • Chae Je-Cheon
    • Proceedings of the Korean Society of Crop Science Conference
    • /
    • 2001.09a
    • /
    • pp.72-90
    • /
    • 2001
  • Environment agriculture carried out from 1999 in Daeho reclaimed saline area, located in central east cost of Choongnam Korea, resulted in dramatic reduction of amount of nitrogen fertilizer and application times and amount of pesticides. The ecological status of Daeho reclaimed saline area was considered to still very sound from the results of ecological survey on flora and fauna. However, it was desirable to adapt precision agriculture for production of high eating quality of rice and preservation of Daeho ecosystem. Especially, precise application of nitrogen and phosphorus fertilizer was recommendable for prevention of water pollution in environment rice cultivation by duck or mud snail or crab. The bioefficacy of Scirpus maritimus and Echinochloa crus-galli in paddy field of environment rice cultivation by duck or mud snail or crab in Daeho reclaimed saline area was revealed very low. Therefor, it was concluded that the pre-measures of reduction of natural weed population were necessary for successful environment agriculture. The most desirable and ideal environmentally sound agriculture in Daeho reclaimed saline area was performance of crop rotation, introduction of legume crops and green manure crops, and also, simultaneous management of crop production and animal husbandry for smooth flow of energy cycle within the closed Daeho ecosystem.

  • PDF

Finite element analysis of the fluid-structure interaction in a compliant vessel (유연 혈관에서 유체-고체 상호작용에 대한 유한요소 해석)

  • Shim, Eun-Bo;Ko, Hyung-Jong;Kamm, Roger D.
    • Proceedings of the KSME Conference
    • /
    • 2000.11b
    • /
    • pp.591-596
    • /
    • 2000
  • Flow through compliant tubes with linear taper in wall thickness is numerically simulated by finite element analysis. Two models are examined: a planar two-dimensional channel, and an axisymmetric tube. For verification of the numerical method, flow through a compliant stenotic vessel is simulated and compared to existing experimental data. Computational results for an axisymmetric tube show that as cross-sectional area falls with a reduction in downstream pressure, flow rate increases and reaches a maximum when the speed index (mean velocity divided by wave speed) is near unity at the point of minimum cross-section area, indicative of wave speed flow limitation or "choking" (flow speed equals wave speed) in previous one-dimensional studies. For further reductions in downstream pressure, flow rate decreases. Cross-sectional narrowing is significant but localized. When the ratio of downstream-to-upstream wall thickness is ${\le}$ 2 the area throat is located near the downstream end; as wall taper is increased to ${\ge}$ 3 the constriction moves to the upstream end of the tube. In the planar two-dimensional channel, area reduction and flow limitation are also observed when outlet pressure is decreased. In contrast to the axisymmetric case, however, the elastic wall in the two-dimensional channel forms a smooth concave surface with the area throat located near the mid-point of the elastic wall. Though flow rate reaches a maximum and then falls, the flow does not appear to be choked.

  • PDF

Electrophysiological and Mechanical Characteristics in Human Ileal Motility: Recordings of Slow Waves Conductions and Contractions, In vitro

  • Ryoo, Seung-Bum;Oh, Heung-Kwon;Moon, Sang Hui;Choe, Eun Kyung;Yu, Sung A;Park, Sung-Hye;Park, Kyu Joo
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.19 no.6
    • /
    • pp.533-542
    • /
    • 2015
  • Little human tissue data are available for slow waves and migrating motor complexes, which are the main components of small bowel motility. We investigated the electrophysiological and mechanical characteristics of human ileal motility, in vitro. Ileum was obtained from patients undergoing bowel resection. Electrophysiological microelectrode recordings for membrane potential changes and mechanical tension recordings for contraction from smooth muscle strips and ileal segments were performed. Drugs affecting the enteric nervous system were applied to measure the changes in activity. Slow waves were detected with a frequency of 9~10/min. There were no cross-sectional differences in resting membrane potential (RMP), amplitude or frequency between outer and inner circular muscle (CM), suggesting that electrical activities could be effectively transmitted from outer to inner CM. The presence of the interstitial cell of Cajal (ICC) at the linia septa was verified by immunohistochemistry. Contractions of strips and segments occurred at a frequency of 3~4/min and 1~2/min, respectively. The frequency, amplitude and area under the curve were similar between CM and LM. In segments, contractions of CM were associated with LM, but propagation varied with antegrade and retrograde directions. Atropine, $N^W$-oxide-L-arginine, and sodium nitroprusside exhibited different effects on RMP and contractions. There were no cross-sectional differences with regard to the characteristics of slow waves in CM. The frequency of contractions in smooth muscle strips and ileal segments was lower than slow waves. The directions of propagation were diverse, indicating both mixing and transport functions of the ileum.

Ultrastructure of Integument of the Smooth Lumpsucker, Aptocyclus ventricosus (Pallas, 1769) (Teleostei: Cyclopteridae) (뚝지, Aptocyclus ventricosus 피부의 미세구조)

  • Jeon, Mi Ae;Kim, Hyejin;Park, Jung Jun;Kim, Jea Won;Lee, Jung Sick
    • Korean Journal of Ichthyology
    • /
    • v.28 no.3
    • /
    • pp.147-155
    • /
    • 2016
  • This study describes the cell type, ultrastructure and histochemical characteristics as a preliminary study for the research on integument of the smooth lumpsucker, Aptocyclus ventricosus in accordance with the physiological and environmental changes using light and electron microscopes. The SEM revealed the presence of well-developed finger printing structure in the skin surface. The skin surface of the smooth lumpsucker showed an irregular folds in cross section of light microscope. Integument is composed of outer epidermal and inner dermal layer. The epidermal layer is a stratified layer composed of epithelial cells, mucous cells, vacuolar cells, and granular cells. Epithelial cells are classified into superficial, intermediated, and basal cell. The superficial cells were the squamous with well-developed microridges on the free surface, and the microridges were covered with glycocalyx. The mucous cells of unicellular gland were mainly distributed in the apical layer of epidermis and contained mucosal materials of neutral glycoprotein. The vacuolar cells of unicellular gland were mainly distributed in the mid and basal layer of epidermis. The proportion of mucous cells and vacuolar cells were $7.0({\pm}1.07)%$ and $40.6({\pm}3.31)%$ of epidermal area, respectively. The granular cells contained membrane bounded secretory granules with high electron density and developed cell organelles in the cytoplasm. The dermal layer was loose connective tissue layer and composed of mainly collagen fibers. It also contained blood vessels and chromatophores of melanophores and reflecting platelets.

Pool Boiling Enhancement of R-123 Using Perforated Plates (다공판을 사용한 R-123 풀비등 열전달 촉진)

  • Kim, Nae-Hyun
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.40 no.5
    • /
    • pp.275-281
    • /
    • 2016
  • In this study, we investigate the pool boiling enhancement caused by perforated plates on top of a smooth surface. We conduct tests using R-123 at atmospheric pressure. It was shown that perforated plates significantly enhanced the pool boiling of the smooth surface. The reason may be attributed to the increased bubble contact area between the plates. The results showed that the enhancement ratio was dependent on the heat flux. At high heat flux, the enhancement ratio increased as the porosity increased. However, at low heat flux, the enhancement ratio decreased as the porosity increased. For the present investigation, the optimum configuration had a pore diameter of 2.0 mm, pore pitch of $2.5mm{\times}5.0mm$ or $5.0mm{\times}5.0mm$, and a gap width of 0.5 mm, which yielded heat-transfer coefficients that are close to those of GEWA-T. The optimum porosity for R-123 was significantly larger than that of water or ethanol. The reason for this may be the large liquid-to-vapor density ratio along with the small latent heat of vaporization of R-123. The perforated plates yielded smaller boiling hysteresis compared with that of the smooth surface.

Isolation and identification of the abundant bacteria in dental caries in children (소아의 치아우식 부위별 우점 세균 분리 및 동정)

  • Kim, Eun-Mi
    • Journal of Korean society of Dental Hygiene
    • /
    • v.18 no.5
    • /
    • pp.843-852
    • /
    • 2018
  • Objectives: The study aimed to isolate the abundant bacteria in dental caries in children and to investigate the bacterial species involved in addition to those that have been previously reported. Methods: The specimens were collected from the supragingival plaques of each dental caries area, pit and fissure caries, deep dentinal caries, smooth surface caries, and dental caries, and from healthy subjects in the control group. Bacteria were cultured from these specimens, DNA was extracted from the isolated bacteria, and the 16S rRNA gene sequences were analyzed and identified. Results: Based on the results of the 16S rRNA gene sequence analysis for the 90 strains of dominant bacteria from the 45 specimens, 5, 7, 8, 7, and 13 species were identified from the supragingival plaques from healthy teeth, pit and fissure caries, deep dentinal caries, smooth surface caries, and dental caries, respectively. In healthy teeth, Actinomyces naeslundii dominated. Corynebacterium durum, Ralstonia pickettii, and Streptococcus intermedius showed equal distribution. The dominant bacterial species in dental caries, S. sanguinis, showed the greatest difference in prevalence in pit and fissure caries. In deep dentinal caries, S. mutans and Lactobacillus rhamnosus were dominant; in smooth surface caries, S. mutans and S. sanguinis were dominant; and in the supragingival plaques of dental caries, S. sanguinis and S. mutans were dominant. Conclusions: The bacterial species isolated from dental caries encompassed four phyla, eight genera, and 22 species. In addition, the SS1-2 strain, belonging to the genus Neisseria, was identified as a new species from among the isolated strains.

Implementation of Smooth Moving Sound Effect in 3D Sound Generation (입체음향 생성에 있어서 자연스러운 이동음 효과의 구현)

  • Myung, Hyun;Kim, Ki-Hong;Kim, Ki-Ho;Kim, Yong-Wan;Kim, Hyun-Bin;Kim, Poong-Min
    • Journal of KIISE:Software and Applications
    • /
    • v.28 no.10
    • /
    • pp.699-705
    • /
    • 2001
  • As it became possible to generate 3D sound on a PC environment due to the advances in computing performance and digital signal processing technology, 3D sound technology gains its focus in the multimedia area Specifically a two-channel based 3D sound technology is being studied by many researchers because of its space efficiency and economical structure. While the positional sound effect is simple in its implementation, the moving sound effect has many problems to be resolved as there are only discrete measured point of HRTF database. In this paper, we propose the method of generating smooth moving sound in a two-channel based 3D sound technique with respect to generating smooth trajectory, and the interpolation method of discrete measured HRTF data. We perform the tests in the PC environment and prove the utility of the proposed method.

  • PDF