• Journal of applied mathematics & informatics
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• v.12 no.1_2
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• pp.219-231
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• 2003

This paper aims to study the problem of combined harvesting of a system involving one predator and two prey species fishery in which the predator feeds more intensively on the more abundant species. Mathematical formulation of the optimal harvest policy is given and its solution is derived in the equiblibrium case by using Pontryagin's Maximum principle. Dynamic optimization of the harvest policy is also discussed by taking E(t), the combined harvest effort, as a dynamic variable. Biological and bioeconomic interpretations of the results associated with the optimal equilibirum solution are explained. The significance of the constraints required for the existence of an optimal singular control are also given.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.658-667
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• 1996

A computer vision system was developed to automatically detect and locate the oyster hinge line, one step in shucking an oyster. The computer vision system consisted of a personal computer, a color frame grabber, a color CCD video camera with a zoom lens, two video monitor, a specially designed fixture to hold the oyster, a lighting system to illuminate the oyster and the system software. The software consisted of a combination of commercially available programs and custom designed programs developed using the Microsoft CTM . Test results showed that the image resolution was the most important variable influencing hinge detection efficiency. Whether or not the trimmed -off-flat-white surface area was dry or wet, the oyster size relative to the image size selected , and the image processing methods used all influenced the hinge locating efficiency. The best computer software and hardware combination used successfully located 97% of the oyster hinge lines tested. This efficienc was achieve using camera field of view of 1.9 by 1.5cm , a 180 by 170 pixel image window, and a dry trimmed -off oyster hinge end surface.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.80-81
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• 1998

In this study, an experiments and numerical simulation of a three chamber pneumatic cylinder for an intelligent AK-knee prosthesis is performed. The cylinder has a variable orifice which can be controlled automatically through a microprocessor controller as needed while amputee gaits. In the experiment, the cylinder was driven by a cam whose trajectory of simulates the normal gait and axial forces of cylinder with different of orifice opening was measured. The numerical simulations was based on thermodynamic and fluid mechanical consideration. The experimental results and the numerical results were in good agreement.

• Proceedings of the KOSOMBE Conference
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• v.1992 no.11
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• pp.130-135
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• 1992

In this paper a new cardiac output control method without pressure sensors is presented for the rotor-driven totally implantable TAH using motor-current wavelet analysis. Theoretical analysis and mock circulation system experiment results show that cardiac output of TAH, which is indeperdent of afterload and sensitively dependent to preload, is well controlled for the independently variable preload.

• Journal of Korean Association for Spatial Structures
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• v.18 no.2
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• pp.25-34
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• 2018

This study investigated a bio-tensegrity structural system that combines the characteristics of a general tensegrity structural system with a biological system. The final research objective is to accomplish a changeability for the structural system as like the movement of the natural bio-system. In the study, we present a shape finding procedure for the two stage bio-tensegrity system model inspired by the movement pattern of animal backbone. The proposed system is allowing a dynamic movement by introducing the concept of "saddle" for the variable bio-tensegrity structure. Several shape finding analysis example and results are presented and shows a efficient validation and suitability.

• Archives of Pharmacal Research
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• v.13 no.4
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• pp.298-305
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• 1990

Based on equal number of cells, supplementation of 10$^{-6}$ M cadimium highly simulated the intracellular amylase. GCT, LDH as well as the glucose and erea content of E carotovora var, carotovaro cells. This was coupled with initiation of highly active GOT, CPK as well as accumulation of cholesterol in the cells. Lanthanum was less active and unable to initiate COT or CPK. Nickel was almost without effect though reduced LDH activity without initiating either enzyme or cholesterol production. Similar stiulations and/or initiations were observed, though to variable extents, when the same concentration of the three elements were supplied to E. carotovora var, citullis or E. toxica. The highest yield of amylase, GPT, GGT or glucose was obtained when E. carotovora var. carotovora was supplemented with Cd + Ni. The highest urea level was recorded in Erwinia carotovara var, cirullis, amended with Cd + La.

• Journal of Biomedical Engineering Research
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• v.18 no.1
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• pp.51-64
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• 1997

A dynamic model of the Korean total artificial heart(TAH) which contains a brushless DC motor, all of mechanical components, the pump system with integrated variable volume space(WS) and the circulatory system model including the bronchial circulation were established Two different sets of seven differential equations were separately derived for the left and right systolic period of the Korean TAH operation. Throughout the computer simulation, a full-state fEedback optimal controller that minimizes the power consumption of the Korean TAH and drives the end stage velocity of the energy converter to zero was developed based upon the optimal control theory. Robustness of the controller were also analyzed with the dynamic model of the Korean TAH.

• The Journal of Fisheries Business Administration
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• v.46 no.3
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• pp.129-141
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• 2015

Because land based aquaculture is restricted by high investment per rearing volume and control cost, good management planning is important in Land-based aquaculture system case. In this paper master production planning was made to decide the number of rearing, production schedule and efficient allocation of water resources considering biological and economic condition. The purpose of this article is to build the mathematical decision making model that finds the value of decision variable to maximize profit under the constraints. Stocking and harvesting decisions that are made by master production planning are affected by the price system, feed cost, labour cost, power cost and investment cost. To solve the proposed mathematical model, heuristic search algorithm is proposed. The model Input variables are (1) the fish price (2) the fish growth rate (3) critical standing corp (4) labour cost (5) power cost (6) feed coefficient (7) fixed cost. The model outputs are (1) number of rearing fish (2) sales price (3) efficient allocation of water pool.

• 보존과학연구
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• s.28
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• pp.75-90
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• 2007

The ancient biomolecular remains are the potential source for paleobiology and paleoanthropology. Especially, ancient human specimens such as bone, teeth, and hair are powerful materials to identify historical origin and migration of ancestor population from the past. However, most excavated human specimens in archaeological sites have commonly problems as natural damage and exogenous contamination. We carried out histological and molecular analyses of excavated bone from the historic sites in South Korea from the recently discovered in tumulus of Seochun and Naju. Biological deterioration of bone was observed anatomically by optical and scanning electron microscope (SEM). We extracted degraded DNA, and amplified hyper variable region (HVR) of mitochondrial DNA (mtDNA) and amelogenin of nucleus DNA. This study applied and examined the relationships between histological preservation and DNA survival in excavated bone.

• Journal of Ecology and Environment
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• v.29 no.4
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• pp.361-364
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• 2006

The objective of the current study was to characterize and apply multiple regression model relating to vegetation values of the plant species over salt marshes. For each salt marsh community, vegetation and soil variables were investigated in the western coast and the southern coast in South Korea. Osmotic potential of soil and $Cl^-$ content of soil as independent variable had positive and negative influences on vegetation values. Multiple regression model showed that vegetation values of 14 coastal plant communities were determined by pH of soil, osmotic potential of soil and sand content. The multiple regression equation may be applied to the explanation of distribution and abundance of plant communities with exiting ordination plots.