• International Journal of Aerospace System Engineering
• /
• 제4권2호
• /
• pp.5-9
• /
• 2017

In a pressurized fuel supply system of aircraft, a flow passage opening device is required to keep fuel continuously transferred from one tank to the other. The device utilizes balancing weights in order to follow up an acceleration at special conditions such as negative g. It is very difficult to test the device in a real high-speed and high-altitude test since severe test conditions and expensive supports are needed. Therefore, this paper deals with performance analysis of a flow passage opening device through low speed aircraft captive flight tests (CFT) including roll and negative-g maneuvers. It is shown that balancing weights in the device can open the passage in accordance with fuel position.

• Animal cells and systems
• /
• 제2권2호
• /
• pp.177-181
• /
• 1998

Blood samples collected from green (chelonia mydas), loggerhead (caretta caretta), and Kemp's ridley (Lepidochelys kempii) sea turtles were analyzed by radioimmunoassay to detect seasonal variations in thyroid hormones and compare levels in wild and captive individuals. Sexual dimorphism in the annual cycle of thyroxine was observed in adult Kemp's ridley. No differences were observed between immature male and female green and loggerhead sea turtles. The level of triiodothyronine was consistently low relative to thyroxine in all species investigated, and captive sea turtles exhibit higher plasms thyroid levels than do wild ones.

• Journal of Ecology and Environment
• /
• 제29권1호
• /
• pp.69-74
• /
• 2006

The captive breeding biology of the Oriental white stork (Ciconia boyciana) was studied over 3 breeding periods. Both the male and female participated in nest building, but the male started to build the nest earlier and spent much time. Time used to build the nest was steadily increased to the egg laying. The copulations were observed $30{\pm}10.53$ (n=3) times in a breeding period. Both male and female incubated their eggs but the female spent more time than the male did. The chicks were hatched $32{\pm}1.29$ (n=6) days after egg laying. Not only the male but also the female took part in the rearing chicks. The male spent more time than the female as chicks grew. The results of this study are useful to assess the ecological soundness of the breeding pair and facilitate the breeding environment in captive breeding of the Oriental white stork.

• 한국군사과학기술학회지
• /
• 제9권2호
• /
• pp.87-95
• /
• 2006

The performance of a microwave missile seeker and radar operating in an air-to-air look-down mode is strongly influenced by the presence of ground clutter In order to correctly account for the effects of ground clutter, it is required to develop a model capable of representing clutter characteristics as a function of range and/or frequency. In this paper, a program to estimate the clutter reflectivity for various ground conditions is developed, using the actually measured data and the data available from open literatures. In addition, clutter characteristics measured for various ground conditions such as sea, agricultural area, urban city and industrial area through the captive flight tests are presented.

• 한국임상수의학회지
• /
• 제32권4호
• /
• pp.389-391
• /
• 2015

Jejunal volvulus was diagnosed in a captive 12-year-old male striped hyena at necropsy. The animal was presented with decreased appetite, dullness, vomiting, and mild abdominal distention intermittently for about two months. Then, the animal was found anorexia, lethargy, depression, red brown colored vomiting materials, and decreased defecation from 10 days before death. At necropsy, jejunal volvulus was found about 1 m in length, and coalescence was observed at the inner membranes of jejunum. The parenchyma of the kidney was congested, and the bladder was filled with hematuria. These conditions might cause shock by renal failure that led to death. To prevent volvulus in a captive striped hyena, it is needed to improve zoo environment and early diagnosis using ultrasonography and X-ray.

• Parasites, Hosts and Diseases
• /
• 제48권3호
• /
• pp.213-217
• /
• 2010

Sarcocystis sp. infection was investigated in 20 necropsied captive wild mammals and 20 birds in 2 petting zoos in Malaysia. The gross post-mortem lesions in mammals showed marbling of the liver with uniform congestion of the intestine, and for birds, there was atrophy of the sternal muscles with hemorrhage and edema of the lungs in 2 birds. Naked eye examination was used for detection of macroscopic sarcocysts, and muscle squash for microscopic type. Only microscopically visible cysts were detected in 8 animals and species identification was not possible. Histological examination of the sections of infected skeletal muscles showed more than 5 sarcocysts in each specimen. No leukocytic infiltration was seen in affected organs. The shape of the cysts was elongated or Circular, and the mean size reached $254{\times}24.5{\mu}m$ and the thickness of the wall up to $2.5{\mu}m$. Two stages were recognized in the cysts, the peripheral metrocytes and large numbers of crescent shaped merozoites. Out of 40 animals examined, 3 mammals and 5 birds were positive (20%). The infection rate was 15% and 25% in mammals and birds, respectively. Regarding the organs, the infection rate was 50% in the skeletal muscles followed by tongue and heart (37.5%), diaphragm (25%), and esophagus (12.5%). Further ultrastructural studies are required to identify the species of Sarcocystis that infect captive wild animals and their possible role in zoonosis.

• 한국컴퓨터정보학회논문지
• /
• 제15권7호
• /
• pp.109-116
• /
• 2010

본 연구에서는 계열 IT서비스 기업을 갖는 국내 대형 그룹사의 IT수준과 IT서비스 기업의 성과에 대한 관련성을 실증적으로 분석하였다. 총 24개 IT서비스 기업과 관련 그룹사를 대상으로 한 연구에서, 관련 가설을 수립하여 집단간 차이분석(t-test)을 통해서 통계적으로 검증하였다. 그 결과, IT서비스사의 SM 매출과 대내 매출, 대내 서비스 역량 및 종합 서비스 역량 그리고 그룹사 자체의 매출액 및 IT 서비스 신규투자 규모가 고객 그룹사의 IT수준에 영향을 주는 것으로 나타났다. 또한 고객 그룹사의 매출, IT서비스 기업의 대내 및 SM 매출이 높은 집단에서 IT서비스 기업의 매출액이 높게 나타났으며, 대외 사업 비중 및 SI 사업 비중이 낮은 집단과, 대내 사업 비중 및 SM 사업 비중이 높은 집단에서 IT 서비스 기업의 서비스 역량이 높게 나타났다.

• 한국해양공학회지
• /
• 제35권5호
• /
• pp.313-326
• /
• 2021

A submerged body with varied control inputs can execute large drift angles and large angles of attack, as well as basic control such as straight movement and turning. The objective of this study is to analyze the dynamic characteristics of a submerged body comprising six thrusters and six control planes, which is capable of a large drift angle and angle of attack motion. Virtual captive model tests via were analyzed via computational fluid dynamics (CFD) to determine the dynamic characteristics of the submerged body. A test matrix of virtual captive model tests specialized for large-angle motion was established. Based on this test matrix, virtual captive model tests were performed with a drift angle and angle of attack of approximately 30° and 90°, respectively. The characteristics of the hydrodynamic force acting on the horizontal and vertical surfaces of the submerged body were analyzed under the large-angle motion condition, and a model representing this hydrodynamic force was established. In addition, maneuvering simulation was performed to evaluate the standard maneuverability and dynamic characteristics of large-angle motion. Considering the shape characteristics of the submerged body, we attempt to verify the feasibility of the analysis results by analyzing the characteristics of the hydrodynamic force when the large-angle motion occurred.

• 대한조선학회논문집
• /
• 제59권5호
• /
• pp.296-305
• /
• 2022

In order to investigate maneuvering characteristics of KCS in waves, captive model test in regular waves was conducted. Purpose of the test is measuring maneuvering hull forces when ship is maneuvering in waves. Model test was carried out using CPMC (Computerized Planar Motion Carriage) of ocean engineering basin in KRISO (Korea Research Institute of Ships and Ocean engineering). Total 6 degrees-of-freedom motion were fixed by two points supporting captive model test device, which is specially designed for this test. This system estimates 6 degrees-of-freedom forces and moments through 12 strain gauge signals. Mapping matrix from strain gauge signals to 6 degrees-of-freedom forces and moments was derived by a well-organized calibration test. Static drift test was conducted in calm sea and in regular waves with various wave conditions. Hydrodynamic coefficients related to drift angle were extracted for each wave conditions, and the effect of waves on course stability was analyzed.

• 유통과학연구
• /
• 제18권4호
• /
• pp.97-106
• /
• 2020

Purpose: Participation of firms in Global Value Chains (GVC) has contributed significantly to the improvement of economic outcomes for firms in developing countries. However, evidence suggests that these economic outcomes are gained at the cost of labourers' poor working conditions. This research contributes to existing literature on GVCs by investigating the influence of different governance structures on economic and social upgrading of firms participating in GVCs. Furthermore, the research attempts to understand the relationship between economic and social upgrading in GVCs. Research design and methodology: Detailed qualitative primary research was carried out in the football industry of Sialkot, Pakistan. The case study approach was employed, and football firms were the unit of analysis. Semi-structured interviews with firms' representatives were conducted. Results: Findings reveal that most firms were found in captive, relational and market governance structures. Furthermore, product and process upgrading were witnessed in all firms; however, social upgrading was observed mostly in captive and relational GVCs. Moreover, social upgrading was linked to economic upgrading in captive and relational networks. Conclusions: The findings from the Sialkot football industry reflect that buyers pay higher prices and margins to their suppliers once they upgrade their products and processes.