• Proceedings of the KSME Conference
• /
• 2003.11a
• /
• pp.875-880
• /
• 2003

Stall inception means the phenomena of rotating stall initiation. The initiation mechanism of rotating stall, the existence of stall precursor, the behavior of stall precursor, stall warning scheme and control scheme are the main interests in stall inception research. Compared to the studies on rotating stall which has long history, the stall inception has been studied for about recent 20 years. After the first discovery of stall precursor in about 20 years ago, many studies were reported on stall inception phenomena. The inception pattern of "mode" and "spike" were found, and some of its characteristics are known. And now the stall inception has become one of the fascinating fields in turbomachinery. This paper reviews the results and analysis methods on stall inception studies.

• Korean Journal of Oriental Medicine
• /
• v.9 no.1
• /
• pp.123-126
• /
• 2003

Advanced glycation end products(AGEs) are largly involved in the pathogenesis of diabetic complications. It is obvious that inhibition of AGEs formation is important in preventing the occurrence and progression of diabetic complications. Therefore, to seek possible AGEs inhibitors in herbal medicines, unprocessed - und processed Puerariae Radix were tested. The inhibitory effect on AGEs formation was slightly increased through processing. Unprocessed-, processed Puerariae Radix and puerarin showed potential inhibitory action than that of positive control, amino guanidine HCI.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.12B
• /
• pp.1636-1646
• /
• 2011

In this paper, we implement IEEE 802.1Qay PBB-TE system and verify interoperability with the commercial PBB-TE product. In order to verify interoperability, we implement the standard protocol as well as the system integrating functions including system kernel control functions. Through interoperability tests with the commercial system, we verify the implemented protocol to perform PBB-TE TESI and ESP configurations, and protection switching as well as monitoring the results.

• Journal of the Korea Furniture Society
• /
• v.12 no.1
• /
• pp.125-130
• /
• 2001

The sofa industry, which is now one of the major furniture industries in Korea, has developed since 1970s as the apartment building boom and the rise of living standards triggered its demand. Among others, durable and high-quality leather sofa had been most favored and excelled other sofas since mid-1980s along with the growth of national economy before IMF control tightened money market in late 1990s. Leather sofa is still favored and its industry has great possibilities to increase as people tend to seek higher and more personalized living conditions with the stabilization of economy. However, there are several problems in the sofa industry due to the current economic difficult conditions, i.e.; 1. It is hard to cut down the cost of raw material as the supply mostly depend on import. 2. It is hard to keep product quality due to technical difficulties. 3. There are still illegal duplicates of foreign or domestic competitors'design. The aim of this study is to examine the reality of the leather sofa industry in Korea and to suggest new vision for its progress.

• The KSFM Journal of Fluid Machinery
• /
• v.7 no.4 s.25
• /
• pp.47-52
• /
• 2004

Cryogenic pump test facility (CPTF) is designed and developed in KARI. Hydraulic and cavitation performance of pump and inducer in cryogenic environment can be measured. Working fluid is liquid nitrogen and operating temperature is $-197^{\circ}C$. Run tank, catch tank of liquid nitrogen and their pressurizing tank has been built and remote tank pressure control system are installed. Maximum power of driving motor is 320 kW and its maximum speed is 32000rpm. Cryogenic fluids and lubricating systems are effectively separated that long test times are acquired. Therefore hydraulic and cavitation performance can be measured accurately and effectively. Pre-cooling test of the facility was successfully accomplished. This facility will contribute greatly to the development of turbopump for KSLV.

• ETRI Journal
• /
• v.24 no.2
• /
• pp.142-152
• /
• 2002

In this paper, we propose and analyze a new multiple access protocol for a local area optical Internet based on a wavelength division multiplexing technique which uses a passive star coupler. The proposed contention-based reservation protocol can support variable-length as well as fixed-length messages for transporting Internet packets with one reservation of a minislot at the beginning of a packet transmission. The minislot is used to reserve the data channel on the basis of the slotted ALOHA protocol and the control node ensures subsequent message transmission on the same wavelength. Thus, all messages need not be broken down to many fixed-length packets, and consecutive messages are transmitted through the same wavelength. Moreover, the proposed protocol reduces the collision probability of minislots and improves wavelength utilization. We determine the maximum throughput and verify the results with simulation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.18 no.4
• /
• pp.369-378
• /
• 2000

The objective of this study is to measures deformation of the structures for stability checks by GPS survey. In this study, 2 points on south side dike of Keum River were measured by 4 sets of GPS(SR9500, Leica) every 4 months for a year, and 3-dimensional displacements of the points were acquired. In order to seek more reliable deformation measurement methods for the offshore structure by GPS, the accuracy of GPS survey with various control points configuration and checking system for detecting unrealistic measurements are also discussed.

• 유체기계공업학회:학술대회논문집
• /
• 2003.12a
• /
• pp.340-345
• /
• 2003

Cryogenic turbopump test facility(CTTF) is designed and developed. Hydraulic and cavitation performance of turbopump in cryogenic environment can be measured. Working fluid is liquid nitrogen and operating temperature is $-197^{\circ}C$. Liquid nitrogen run tank, catch tank and pressurizing tank has been built and remote tank pressure control system are installed. Maximum power of turbopump is 320kW and its maximum speed is 32000rpm. Cryogenic fluids and lubricating systems are effectively separated that long test times are acquired. Therefore hydraulic and cavitation performance can be measured accurately and effectively. This facility will contribute greatly to the development of turbopump for KSLV.

• Proceedings of the KSRS Conference
• /
• 2003.11a
• /
• pp.110-112
• /
• 2003

The researchers, who seek geological and environmental information, depend on the remote sensing and aerial photographic datum from various commercial satellites and aircraft. However, the adverse weather conditions and the expensive equipment can restrict that the researcher can collect their data anywhere and any time. To allow for better flexibility, we have developed a compact, a multispectral automatic Aerial photographic system. This system's Multi-spectral camera can catch the visible (RGB) and infrared (NIR) bands (3032${\ast}$2008 pixel) image. Our system consists of a thermal infrared camera and automatic balance control, and it managed and controlled by a palm-top computer. And it includes a camera gimbals system, GPS receiver, weather sensor and etc. As a result, we have successfully tested its ability to acquire aerial photography, weather data, as well as GPS data, making it a very flexible tool for environmental data monitoring.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.14 no.23
• /
• pp.47-55
• /
• 1991

In automated assembly line, an automatic guided vehicle system(AGVS) represents a mire versatile means of moving materials automatically. In this paper, the vehicles not only provide the transportation medium between workstations but also as mobile workstations. The objective for the developed model is the determination of the appropriate time to control AGV based assembly line in order to minimize production makespan while maximizing the efficient use of vehicles. In this paper, we consider the finished goods of two types which are produced in assembly line. The assembly line is considered with and without queue. Because no buffer are present in case 1. this model seeks to determine the point in time at which vehicles should be launched in the assembly line without experiencing a delay. The case 2 model also seek to determine the vehicle launch times while minimizing production makespan. The assumption in this model is that the maximum queue size cannot exceed 1 at any time.