• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1303-1306
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• 2005

The mechanical properties of bellows, such as the extensibility and the strength can be changed depending on the shape. For the shipbuilding material, it is favorable that the fatigue life is long due to the elastic property and the reduction of thermal stress in piping system. Nowadays, the domestic production and design of bellows are based on the E.J.M.A Code. Therefore, the design standard is in need because of much errors and lack of detailed analysis. In this study, it is attempted to find out the optimal shape of U-type bellows using the finite element method. The effective factors, mountain height, length, thickness, and number of mountains and the length of joint are considered and the proper values are chosen for the simulation. The results shows that if the number of mountains are reduced, the volume decreases while the stress increases. However, the number of mountains are increased, the volume increases above the standard volume and the stress obviously increases. In addition, the effect of the thickness of bellows on the stress is very large. Both of the volume and stress are decreasing at a certain lower value region.

• 대한의용생체공학회:의공학회지
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• 제28권4호
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• pp.577-584
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• 2007

Uroflowmetry is non-invasive and easily performed to diagnose benign prostatic hypertrophy(BPH) frequent in aged men. Weight change during urination is usually measured to estimate the urinary flow rate by a load cell, but sensitive to any impacts against the bottom of the container, leading to unnecessary noise generation. Moreover, load cells are relatively expensive raising the production cost. The present study proposed a new technique, measuring hydraulic pressure on the bottom of the urine container to evaluate the urinary volume. Low cost pressure transducer enabled almost perfectly linear relationship between the urine volume and the hydraulic pressure. During both the simulated and human urination experiments, variance of the pressure signal was more than 50% smaller than the weight signal acquired by a load cell, which demonstrated that the impact noise was decreased to a great degree by pressure compared to weight measurement.

• Journal of Advanced Marine Engineering and Technology
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• 제28권7호
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• pp.1055-1062
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• 2004

As for the Production of internal combustion engines there has been further movement toward development of high Performance engines with improved fuel efficiency as well as a lightweight and a small size. These tendencies help to solve the problems in engines for example, such as thermal load. abnormal combustion and so on. In order to investigate these Problems, a thin film-type probe for measuring instantaneous temperature has been suggested. A method for manufacturing such a probe was established in this study The instantaneous surface temperature of a constant volume combustion chamber was measured by using this probe and the heat flux was obtained through Fourier analysis In order to thoroughly understand the characteristics of combustion. authors measured wall temperature of combustion chamber and calculated heat flux through a cylinder wall while varying the protrusion height of probe. For these Purposes, the instantaneous surface temperature probe was developed. thereby making possible the analysis of instantaneous temperature of wall surface and the detection of unsteady heat flux in the constant volume combustion chamber.

• Fisheries and Aquatic Sciences
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• 제3권2호
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• pp.156-162
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• 2000

Model experiments for a purse seine were carried out in order to measure the geometry of net shape and to estimate an enclosed volume by using 1177 scale model purse seine of 12.62m float line from an offshore mackerel purse seine. A model purse seine was set from a net box of shooting equipments and then pursing and hauling net by hauling equipment. The 3- D geometry shape of the purse seine net during hauling operation was measured by video image processing and tension of purse line by load cell. The 3-D geometry of the model purse seine during hauling operation could be represented with variables such as a ratio of shooting diameter or maximum net depth and a ratio of hauling operation time. Horizontal shapes of float line and lead line were varied from a circle after shooting to an ellipse with pursing and hauling. Projected lateral shape of purse line was observed and formulated as a shape of a water drop. The cross sectional shapes of curved net from two directions were varied such as sine function or polynomial curves. Therefore, enclosed volume of a purse seine in relation to fish school behaviour can be approximated using two main variables from relevant equations.

• Fisheries and Aquatic Sciences
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• 제13권4호
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• pp.308-314
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• 2010

Larvae of Palaemon serrifer were reared in the laboratory under three different temperature regimes ($15^{\circ}C$, $20^{\circ}C$, $25^{\circ}C$) to study the effects of rearing temperature on larval survival and growth, as well as other traits such as embryo volume, number of embryos (fecundity), incubation period, development. Mode and development period. Growth pattern was analyzed by measuring the molt increment and intermolt period. The intermolt period consistently increased with size and instar number and was shortest at $25^{\circ}C$. However, molt increments generally decreased with instar number. Number of embryos varied from 552 to 1355. The relationship between the number of embryos and carapace length was expressed by the equation (fecundity) y=2.7744x+0.208 ($R^2$=0.7961). Egg volume was a primary factor affecting other life-history traits. Egg volume was $0.078\;m^3$, which is relatively small thus embryos exhibited a relatively short incubation period and a comparatively short development period, and the nutritional mode was planktotrophic. Brood production was followed by a fast parturitional pattern. Most ovigerous females had mature ovaries when the parturial molt occurred soon after eclosion.

• Asian-Australasian Journal of Animal Sciences
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• 제3권1호
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• pp.47-52
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• 1990

During prolonged exposure to the sun for 8 h each day for 10 days in which the highest ambient temperature around 14:00 h was $39^{\circ}C$, buffaloes exposed to the sun without shade increased the turnover of body water by 35% and 76% on day 5 and day 10 of exposure respectively. The total body water markedly decreased on day five and this amount was maintained thereafter. Plasma and blood volumes did not change significantly on day five but markedly decreased on day 10. Packed cell volume significantly decreased on day five and day 10 of the exposure period. The reduction of packed cell volume on day 10 coincided with the decrease in total plasma water. On day 10 of the exposure, an increase in the rate of liquid flow from the rumen was noted. It is concluded that on the fifth day of exposure, the increase in the evaporative cooling process was attributed to initial mobilization of water from the intracellular compartment. The reduction of both plasma and cell volumes occurring from day five to day 10 indicated a loss of body water from both intracellular and extracellular compartments.

• Animal cells and systems
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• 제7권2호
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• pp.123-125
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• 2003

We studied the nectar secretion of the Japanese Camellia (Camellia japonica L.), an evergreen tree and observed its floral visitors during the day. The mean volume of nectar secreted, during daylight (08:31 to 16:30 h) was 30.26$\pm8,29ml$ (SD) (n = 27). During the late afternoon and overnight (16:31 to 08:30 following day), 100.54$\pm54.85$(n = 27) of nectar was secreted. Total volume measured when flowers were sampled once every two hours for an eight-hour period was approximately one-half the volume which was measured when the flowers were sampled only once after eight hours. The mean nectar volume secreted was 8.55$\pm8.3ml$(n = 30) between 08:31 to 10:30, 4.38$\pm$6.1 ml (n = 30) between 10:31 to 12:30, 4.6$\pm5.4ml$(n = 30) between 12;31 to 14:30, and 4.02$\pm3.5ml$(n = 30) between 14:31 to 16:30 hours. During the day, Japanese Camellia flowers were principally visited by the Japanese white-eye (Zosterops erythropleura erythropleura 5.), a native bird, although insects and squirrels also visited to a lesser degree.

• 한국정밀공학회지
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• 제25권1호
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• pp.72-78
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• 2008

Metal stamping is widely used in the mass-production process of the automobile. During the stamping process, air may be trapped between the draw die and the panel and/or between the punch and the panel. Air pocket rapidly not only increases forming load in the final stage, but also deforms the product just formed by compressive air inside the air pocket in knockout process. To prevent these problems air bent holes are drilled in the die to exhaust the trapped air but all processes associated with air bent holes are performed by empirical know-how of workers in the field due to lack of researches. Therefore this study developed an automated design system for predicting the shape and position, and volume of air pocket on the draw die by using the AutoLISP language under AutoCAD circumstance. The system is able to display the shape of air pocket occurred in the draw die and to calculate automatically its volume by strokes. So it makes a stepping stone to calculate theoretical size of an air bent hole and numbers according to it by predicting and analyzing the position and volume of air pocket. Results obtained from the system enable the designers or manufacturers of the stamping die to be more efficient in this field.

• 한국농공학회지
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• 제41권3호
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• pp.81-90
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• 1999

The purpose of this study is to examine the uses of fly ash asa type of construction material. This paper presents the results of research performed to identify optimum mix proportions for production of lowable fill with high volume fly ash content . The fly ash used in this study met the requirements of KS L 5405 and ASTM C 618 for Class F material. The flowable fill with high volume fly ash content was investigated for strength and flowability characteristics. Tests were carried out on flowable fill designed to have 10 ~15kgf/$\textrm{cm}^2$ compressive strength at 28 days with fly ash contents of approximately 260kgf/㎥. Slump was held at 25$\pm$1cm for all mixtures produced to range from 5kgf/$\textrm{cm}^2$ to 14kgf/$\textrm{cm}^2$ compressive strengths at 28 days. To produce flowable fill with high volume fly ash , first the influential variables were identified in an experimental study based on factorial design. Among the proportioning variables investigated, cement ,fly ash, and sand contents were found to have statistically significant effect on strength and slump of flowable fill . Subsequently, response surface analysis techniques were used to devise an experimental program that helped determine the optimum combinations of the selected influential variables based on material properties and cost. The optimized flowable fill were then technically evaluated. It is shown that flowable fill has acceptable compressive strength , slump flow, hardening time, and permeability.

• 열처리공학회지
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• 제16권4호
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• pp.216-223
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• 2003

In the production of internal combustion engines, there have been trends to develop the high performance engines with improved fuel efficiency, lighter weights and smaller sizes. This trends help to answer problems related to thermal load and abnormal combustion, etc. in these engines. In order to investigate these problems, a thin film-type probe and its manufacturing method for instantaneously measuring surface-temperatures have been proposed in this study, Instantaneous surface temperature of a constant volume combustion chamber was measured by this probe and heat flux was obtained by Fourier analysis. In order to thoroughly understand the characteristics of combustion, the authors measured the wall temperature of the combustion chamber and computed heat flux through a cylinder wall while varying the protrusion height of the probe have been measured. To achieve the above goals, a instantaneous temperature probe was developed, thereby making possible the analysis of the instantaneous temperature of wall surface and the detection of unsteady heat flux in the constant volume combustion chamber.