• Preventive Nutrition and Food Science
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• 제20권4호
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• pp.266-275
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• 2015

Exposure to cadmium (Cd) has harmful effects on the liver and kidney. Resveratrol (RES) is an herbal substance that functions as a protective mediator. This study aimed to investigate the effects of RES on the histology of liver and kidney in Cd-exposed mice. Male mice were divided into 4 groups daily receiving normal saline (1 mL normal saline/d), Cd (1 mg/kg/d), RES (20 mg/kg/d), and Cd plus RES, respectively. After 4 weeks, the liver and kidney components were evaluated using stereological methods. The total volume and number of hepatocytes, and volume of fibrous tissue were respectively increased by 34%, 58%, and a 3-fold in the Cd-exposed mice in comparison to the control animals (P<0.03). On the other hand, the volume of the main vasculature (sinusoids and central veins) was decreased by 36% in the Cd group compared to the control mice (P<0.03). Considering the kidney, the results showed a 3-fold increase in the total glomeruli volume and a 7-fold increase in fibrous tissue in the Cd-treated group compared to the control mice (P<0.03). After Cd treatment, a 32% reduction was observed in the volume and length of the proximal and distal convoluted tubules. RES-treatment alone did not induce any structural changes. In comparison to the Cd group, an increase in the normal components of the liver and kidney and a decrease in the formation of the fibrous and degenerated tissues were observed in the Cd+RES-treated mice (P<0.03).

• 제어로봇시스템학회논문지
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• 제8권1호
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• pp.21-27
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• 2002

Inspection and shape measurement of three-dimensional objects are widely needed in industries for quality monitoring and control. A number of visual or optical technologies have been successfully applied to measure three-dimensional surfaces. However, those conventional visual or optical methods have inherent shortcomings such as occlusion and variant surface reflection. X-ray vision system can be a good solution to these conventional problems, since we can extract the volume information including both the surface geometry and the inner structure of any objects. In the x-ray system, the surface condition of an object, whether it is lambertian or specular, does not affect the inherent characteristics of its x-ray images. In this paper, we propose a three-dimensional x-ray imaging method to reconstruct a three dimensional structure of an object out of two dimensional x-ray image sets. To achieve this by the proposed method, two or more x-ray images projected from different views are needed. Once these images are acquired, the simultaneous algebraic reconstruction technique(SART) is usually utilized. Since the existing SART algorithms have several shortcomings such as low performance in convergence and different convergence within the reconstruction volume of interest, an advanced SART algorithm named as USART(uniform SART) is proposed to avoid such shortcomings and improve the reconstruction performance. Because, each voxel within the volume is equally weighted to update instantaneous value of its internal density, it can achieve uniform convergence property of the reconstructed volume. The algorithm is simulated on various shapes of objects such as a pyramid, a hemisphere and a BGA model. Based on simulation results the performance of the proposed method is compared with that of the conventional SART method.

• Clinical and Experimental Reproductive Medicine
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• 제50권3호
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• pp.160-169
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• 2023

Objective: Cryptorchidism is one of the main causes of infertility and can result in testicular cancer. This study aimed to present quantitative data on the damage caused by cryptorchidism using stereological analysis. Methods: Thirty newborn rats were randomly divided into control and experimental groups. The experimental group underwent surgery to induce unilateral cryptorchidism in the left testis, whereas the control group underwent a sham surgical procedure 18 days after birth. The testes were removed at designated time points (40, 63, and 90 days after birth) for stereological evaluation and sperm analysis. Total testicular volume, interstitial tissue volume, seminiferous tubule volume and length, and seminiferous epithelium volume and surface area were measured. Other parameters, such as sperm count, sperm morphology, and sperm tail length, were also examined. Results: Statistically significant differences (p<0.05) were observed between the experimental and the control groups at different ages regarding the volumes of various parameters, including the surface area of the germinal layer, the length of the seminiferous tubules, sperm count, and sperm morphology. However, no significant differences were observed in the epithelial volume and the sperm tail length of the groups. Conclusion: Given the substantial effect of cryptorchidism on different testicular parameters, as well as the irreversible damage it causes in the testes, it is important to take this abnormality seriously to prevent these consequences.

• 한국도로학회논문집
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• 제11권3호
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• pp.121-128
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• 2009

본 연구는 기존 정주기식 신호제어로 인하여 비효율적으로 운영되고 있는 3지 교차로의 문제점을 보완하는 방안으로써 반감응 신호제어를 기본으로 하고 보행자작동신호기를 사용하는 신호운영방식의 효율성을 분석하였다. 반감응 신호제어의 경우 부도로에 교통량이 적을 때 주도로의 교통소통을 원활히 하여 교차로 내 지체를 감소시킬 수 있으며, 보행자작동신호기는 보행자가 없음에도 불구하고 보행자 신호를 작동시켜 발생하는 불필요한 대기시간을 줄일 수 있는 장점을 가지고 있다. 위의 두 가지의 장점을 모았을 경우 기존의 정주기식 신호제어와 반감응식 신호제어에 비하여 얼마나 효과가 있는지 미시적 시뮬레이션 프로그램인 VISSIM을 사용하여 정량화된 차량당 평균지체 감소의 정도를 분석하고자 하였다. 본 연구는 인천의 1개 3지 교차로를 대상으로 현장조사를 실시하였고 각각의 신호제어 방식에 따라서 보행자 교통량을 변화시켜 민감도 분석을 실시하였다. 시나리오 별 분석을 통하여 차량당 평균지체시간을 비교한 결과, 대상교차로는 정주기식 신호제어에 비하여 보행자작동신호기를 이용한 신호제어방식이 최소 3.7초(10%), 최대 6초(16%)의 감소효과를 나타내었으며 반감응식 신호제어와의 비교에서는 보행자교통량이 측정교통량의 20% 이하일때보다 효율적인 것으로 나타났다.

• 생물환경조절학회지
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• 제31권4호
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• pp.444-451
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• 2022

최근 토마토 수경재배가 증가하며 장기 재배가 일반화 되고 있다. 수경재배에서는 작물의 양분과 수분 요구도를 고려하여 적정 양액을 공급하는 것이 생산성, 자원의 이용, 환경보전 측면에서도 매우 중요한데 장기재배에서는 계절적인 환경변화가 심하므로 이것을 고려한 급액 관리가 매우 중요하다. 따라서 코이어 배지를 이용한 토마토 장기재배에서 급액량이 생육과 수량에 미치는 영향을 구명하고자 하였다. 온실 외부에 설치된 일사 센서로 적산일사를 기준으로 급액 횟수를 조절하였으며, 생육시기별로 급액 기준을 변경하며 4수준(High, Medium high, Meidum low, Low)으로 급액량을 달리 처리하였다. 급액량이 많을수록 배액률이 높았으며 배액의 EC가 지나치게 높아지는 것을 방지 할 수 있었다. 재배기간이 경과하면서 배액 EC가 높아졌는데 급액량이 적은 처리일수록 상승 폭이 컸다. 초장은 급액량이 가장 적은 처리구가 다른 처리구에 비하여 작았고 마디수와 화방의 발생 수는 급액량에 영향을 받지 않았다. 착과수는 전체적으로는 급액량의 영향을 크게 받지 않았으나 저온기에 발생한, 12-15화방에서는 급액량이 가장 많았던 처리구가 착과수가 적었다. 배꼽썩음과는 급액량이 가장 적은 처리구가 많았고 발생 시기도 빨랐다. 과실의 크기는 High 처리구가 컸으나 전체 수량은 Medium high 처리가 가장 많았다. 시험의 결과로 코이어를 이용한 토마토 수경재배에서 급액량이 근권의 양·수분 안정화와 생산성에 미치는 영향과 적정한 급액 관리의 중요성을 확인할 수 있었다. 따라서 최근에 보급되고 있는 복합환경제어시스템에 근권의 정보를 기준으로 정밀급액제어 알고리즘을 적용한다면 수경재배 제어기술 발전과 더불어 작물의 생산성 향상에도 기여할 수 있을 것으로 판단되므로 이에 대한 지속적인 연구가 필요할 것이다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2003년도 The Fifth Asian Computational Fluid Dynamics Conference
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• pp.86-87
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• 2003

Unstructured grid system is suitable for flows of complex geometries. For problems with moving boundary walls, the grid system must be changed and deformed with time if we use a body fitted grid system. In this paper, a new moving-grid finite-volume method on unstructured grid system is proposed and developed for unsteady compressible flows with shock waves. To assure geometric conservation laws on moving grid system, a control volume on the space-time unified domain is adopted for estimating numerical flux. The method is described and applied for two-dimensional flows.

• 전기학회논문지
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• 제63권8호
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• pp.1140-1145
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• 2014

Tunnel lighting is composed of entrance zone, interior zone and exit zone by KS C 3703. We have to consider adaptation at entrance zone and exit zone lighting to prevent deteriorate visibility like black hole and white hole phenomenon. So External luminance, vehicle velocity and traffic volume should be considered in threshold zone lighting and vehicle speed and traffic volume should be considered in interior zone lighting. But existing tunnel lighting system is not good at visibility and economic because that is only controled by external luminance. So in this paper, We improve visibility and economic of tunnel lighting system using fuzzy reasoning according to external luminance, vehicle velocity, traffic volume.

• 한국생활과학회지
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• 제22권6호
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• pp.723-736
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• 2013

To examine the quality characteristics of bread made of different amounts of chia seed powder, a functional food ingredient, this study made bread by adding chia seed powder by 1%, 3%, and 5% of the flour weight. When bread dough properties were determined using mixograph, all doughs were appropriate for bread-making. In the evaluation of fermentation rate, the dough with 3% of chia seed powder CS 3 showed the most favorable fermentation rate during the first 60-min fermentation of the bread. According to CrumbScan, the fineness of bread pores were higher in control group than bread loaves containing chia seed powder. The volume of bread in control group was significantly lower than those of other experimental groups. The volume and specific volume were highest when chia seed powder was added by 3%. According to preference analysis, appearance and taste was best in CS 3, showing the highest overall score in preference. Therefore, the optimum amount of chia seed powder is identified to be 3% in bread-making.

• Clinical and Experimental Pediatrics
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• 제50권5호
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• pp.430-435
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• 2007

Even though we drink and excrete water without recognition, the amount and the composition of body fluid remain constant everyday. Maintenance of a normal osmolality is under the control of water balance which is regulated by vasopressin despite sodium concentration is the dominant determinant of plasma osmolality. The increased plasma osmolality (hypernatremia) can be normalized by the concentration of urine, which is the other way of gaining free water than drinking water, while the low plasma osmolality (hyponatremia) can be normalized by the dilution of urine which is the only regulated way of free water excretion. On the other hand, volume status depends on the control of sodium balance which is regulated mainly by renin-angiotensin-aldosterone system, through which volume depletion can be restored by enhancing sodium retention and concomitant water reabsorption. This review focuses on the urine concentration and dilution mechanism mediated by vasopressin and the associated disorders; diabetes insipidus and syndrome of inappropriate antidiuretic hormone secretion.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.551-556
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• 2001

The filling pattern technique based on the finite element method and Eulerian mesh advancement approach has been developed to analyze incompressible transient viscous flow with free surfaces. The governing equation for flow analysis is Navier-Stokes equation including inertia and gravity effects. The penalty and predictor-corrector methods are used effectively for finite element formulation. The flow front surface and the volume inflow rate are calculated using the filling pattern technique to select an adequate pattern among four filling patterns at each triangular control volume. Using the proposed numerical technique, the collapse of a dam has been analyzed to predict flow phenomenon of fluid and the predicted front positions versus time have been compared with the reported experimental result.