• Ocean and Polar Research
• /
• v.28 no.3
• /
• pp.237-243
• /
• 2006

The ages of sandfish, Arctoscopus japoninis sampled from the eastern sea of Korea, were determined by the transverse section method of otoliths. Ages were assigned to every individual according to the number of opaque zones, and then fitted to the von Bertalanffy growth equation. Estimated equations were $L_t=25.90(1-e^{-0.2976(t+0.4447)})$ for females and $L_t=21.38(1-e^{-0.2917(t+1.2087)})$ for males, where t is age (year) and $L_t$, is body length (mm) at age t. These two equations were significantly different and the body length of females calculated from the equation was larger than that of males except at 1 year old.

• Journal of the korean society of oceanography
• /
• v.37 no.3
• /
• pp.108-115
• /
• 2002

To Investigate the distribution of resting eggs at the intertidal zone, Gomso Bay, samples were taken from the top of the sediments to 10 cm depth at four sites using a cylindrical corer in February, 1997. Additional samples were also taken from one station at subtidal zone to compare the distributions between the inter- and subtidal zones. The resting eggs of few copepods, Acartia pacifica, Centropages abdominalis, Calanopia thompsoni, and Tortanus forcipatus were studied. Mostly, the abundance of the resting eggs in the lower intertidal zone was greater than that in the upper intertidal zone, but was not significantly different from that in the subtidal zone. The abundance of the resting eggs in the intertidal sediments was related with the grain-size and moisture content of sediments. Intertidal sediments are potential egg banks like subtidal sediments.

• Journal of the Optical Society of Korea
• /
• v.4 no.1
• /
• pp.58-61
• /
• 2000

Viewing zone shape and size perform a key role in creating viewing comfort for the viewer. The horizontal and vertical sizes of viewing zones, formed by a full color transmission type holographic screen with a stereoscopic image projection are investigated. The screens have been recorded as holograms of a narrow stripe shaped object with different width; to extend the vertical size of the viewing zone the holograms were exposed two times with the hologram shifting between exposures. The viewing zone parameters were measured as a function of the stripe width of the object and of the exit pupil size of projection optics for several holographic screens having the size of the 30 $\times$ 40 $\textrm{cm}^2$.

• The Plant Pathology Journal
• /
• v.23 no.4
• /
• pp.233-238
• /
• 2007

Twenty five isolates of Sclerotinia sclerotiorum were recovered from different infested fields of vegetable along the heavily cultivated crops in Jordan valley. Cellulase and pectinase activities of those isolates were detected using CMC and pectin agar media, respectively. Diameter of the clearing zones on those media represented the level of such enzymatic activities, characteristic of each isolate. The virulence of those isolates was studied using a squash (Cucurbita pipo) cultivar under a greenhouse condition. The significance of correlating the enzymatic activity with the virulence of the isolates was ascertained and discussed.

• Journal of Korean Society on Water Environment
• /
• v.26 no.1
• /
• pp.28-34
• /
• 2010

This study was conducted to assess the validity of fecal coliforms to fecal streptococci ratio (FC/FS) for distinguishing the human from animal origin of fecal pollution in surface water. FC/FS ratio determined in effluent from municipal wastewater and human feces treatment plant (WWTP) and in downstream close to discharge of human feces was above 4 which indicates human origin. However FC/FS ratios determined seasonally in other water zones of the Nakdong River, even in the same sampling site, varied differently (above 4 or less than 0.7) due to different survival time of FC and FS and other environmental factors such as rainfall in watershed. Compared to other season, FC/FS ratios in winter were much lower regardless of the origin. It is concluded that the FC/FS ratio determined in surface water is not always valid for determining the origin of fecal pollution.

• The KSFM Journal of Fluid Machinery
• /
• v.2 no.1 s.2
• /
• pp.56-63
• /
• 1999

In this study, the performance prediction programs for centrifugal pumps are developed. To estimate the losses in the centrifugal pump impellers, a two-zone model and TEIS(two elements in series) model are applied to the program. The basic concept of a two zone model considers the primary zone that is an isentropic core flow and the secondary zone that has a non-isentropic region at the impeller exit. The flow goes through two different zones and is mixed out at the impeller exit and the mixing process occurs with an increase in entropy, a decrease in total pressure. The level of the core flow diffusion in an impeller was calculated using TEIS(two elements in series) model. The effects of various parameters which are used in this program on the prediction of head and efficiency are discussed. The correlation curves used to select the effectiveness of the primitive TEIS model were suggested according to the specific speed of the centrifugal pumps.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.35 no.4
• /
• pp.171-178
• /
• 2012

A possible heuristic to solve metropolitan area vehicle routing problems with variable vehicle speeds is suggested in this research. Delivery hours are classified into 4 different time zones to make variable vehicle speeds no change within the same time zone to make TDVRP simple to solve. The suggested heuristic consists of 2 stages such as initial solution development step and initial solution improvement step. A computer program using C++ is constructed to evaluate the suggested heuristic. Randomly generated vehicle routing problems are used for the experiments. This heuristic could be helpful to logistics companies by increasing delivery efficiencies since the 4 zone classification is taken from the observed traffic information offered by a local government.

• Journal of the Semiconductor & Display Technology
• /
• v.11 no.4
• /
• pp.7-12
• /
• 2012

Extrusion is one of the most important operations in the polymer-processing industry. Development of models for extrusion and computer tools offer a route to developing reliable and optimized process designs. The models are based on the analysis of physical phenomena encountered during the process. Balance equations for mass, momentum and energy are fundamental to the problem. A predictive computer model has been developed for the single screw extruders with conventional screws of different geometry. The model takes into account melting zones of the extruder and describes an operation of the extruder system, making it possible to predict mass flow rate of the polymer, pressure and velocity profiles along the extruder screw channel. The simulation parameters are the material and rheological properties of the polymer; the screw pitch, and screw speed.

• Journal of Plant Biology
• /
• v.17 no.3
• /
• pp.107-112
• /
• 1974

Leaf temperature is complicated with the microclimate and the dry matter production in a plant community. But a daily change of leaf temperature varying by the locality in plant body or plant community is not yet clear. To resolve such a question, following experiment was designed; Helianthus tuberosus L., Glycine max L., Zea mays L., Impomoea batatas Lam., and Cucurbita moschata var. toonas Makino were planted in the different sandy loam, $2m{\times}2m-quadrat$, which has a eastern, southern, western and northern edge. In each plot 17-25 plants were planted and the distances between individuals spaced uniformly. And leaf temperature were measured by MR3-C type thermistor from 14th May through 20th August. It is seems that the upper leaf is affected by solar radiation, the lower leaf by released heat from the earth and the middle leaf by the conditions of both zones. Measuring the temperature of a leaf that is on terminal, central, left and right margins and base part, temperature of control plant in a leaf was sloped during about two hours from noon. It is noticeable as a "noon sleeping" phenomenon.henomenon.

• Proceedings of the KSR Conference
• /
• 2008.06a
• /
• pp.1213-1220
• /
• 2008

In this study, the crashworthy design guidelines for the high speed EMU were derived and numerically evaluated. As for this high speed train, there are several different features from the KTX in that the conventional type bogies are adopted and the front end car (TC car) accommodates passengers. It is natural that the impact acceleration of the front end car should be controlled under the appropriate level stipulated at safety regulations for collision accidents. Also, car-to-car interfacing structures and devices should be deliberately designed to prevent overriding and telescoping mechanisms. As the first step for these design countermeasures, it was studied that how much impact energy should be absorbed at the energy absorbing zones and devices of each carbody to satisfy the impact acceleration regulations of the safety regulations. These results will be used as the crashworthy design guidelines for the high speed train in the next year research.