• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.6
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• pp.812-818
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• 2002

Spatio-temporal distributions of nighttime fishing fleet are descirbed with the aid of geographic information system(GIS) technology in the East/Japan Sea, using daily mean composite images of the Defense Meteorological Satellite Program(DMSP) /Operational Linescan System(OLS) in 1993. We selected a study area from $30^{\circ} N to 44^{\circ} N in latitude and from 124^{\circ} E to 142^{\circ}$ E in longitude in order to describe the monthly and seasonal changes of nighttime fishing fleet. The GIS software package Image Analyst (ArcView 3) are used to analyze spatio-temporal distributions of fishing nut. And the OLS images of nighttime visible band provide useful information about the spatio-temporal distribution of the fishing nut. Density areas of nighttime fishing fleet are around Tsushima/korea Strait. the east coast of the Korea Peninsula, the coast of Honshu, and around Yamato Bank.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.6
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• pp.529-534
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• 2014

Pyrotechnic devices are widely used for space appendages. However, a cube satellite requirements do not permit the use of explosive pyrotechnic device. A nichrome burn wire release has typically been used for holding and release of deployable appendages of the cube satellite due to its simplicity and low cost. However, relatively low mechanical constraint force and system complexity for application of multi-deployable systems are disadvantages of the conventional mechanism. To overcome these drawbacks, we developed a hinge driving segmented nut type holding and release mechanism based on the nichrome burn wire release. The functional performance of the mechanism has been verified through release function test, static load test and shock level measurement test.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.10
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• pp.827-832
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• 2013

Heating wire cutting type separation mechanism has been widely used for cube satellite applications due to its design constraints such as small size of $10cm{\times}10cm{\times}10cm$ and light weight of less than 1kg. In addition, usage of pyro technic device is not allowed for cube satellite application. The conventional methods have some disadvantages of relatively small mechanical constraint force and the system complexity for the multi-deployable systems. In this paper, a separation nut type non-explosive separation mechanism has been proposed and investigated. The effectiveness of the design has been verified through the qualification tests of the mechanism.

• Korean Journal of Materials Research
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• v.10 no.8
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• pp.551-557
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• 2000

Cu-based leadframe sheets were oxidized ic a hot alkaline solution to black-oxide layer on the surface and molded with epoxy molding compound(EMC), and finally machined to form sandwiched double-cantilever beam(SDCB) and sandwiched Brazil-nut(SBN)specimers to measure the adhesion strength of leadframe-EMC interface. The SDCB and the SBN specimens were designed to measure the adhesion strength in terms fracture toughness under puasi-mode I and mixed mode loadinf, respectively. After the tests, fracture surfaces were analyzed paths were observed in the SDCB-tested speciments, failure paths varied with crack speed and loading conditions.

• Journal of Crop Science and Biotechnology
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• v.10 no.4
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• pp.223-230
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• 2007

Vitellaria paradoxa commonly called shea is an important agro forestry and fruit-bearing species present in four agro-ecological zones of Cameroon. The goal of this work was the morphological characterization of certain populations of V. paradoxa which will serve as a necessary step for a subsequent genetic study of the species. Morphological observations related to 20 agronomic traits, studied on 8-13 trees selected from each of the eight shea populations across four different agro-ecological zones located in four provinces of Cameroon were studied. The study showed that there was a variation between the populations, related to the traits measured on the trunk, fruit, nut, and leaf. Three shapes of the tree(ball, broom, and trained), five shapes of the fruit(round, oblong, reversed pear, ovoid, and oblong), three colors of the nut(clear brown, dark brown, and blackish brown) were identified. The principal component analysis(PCA) carried out on the quantitative characters revealed 72% of the total variance expressed on the first and second main axis. This variation was essentially explained by the traits measured on the fruits and on the nuts. The analyses showed that only the traits of the fruits and the nuts were discriminative. The shea populations studied were structured into two distinct groups using these discriminative traits.

• Korean Journal of Materials Research
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• v.9 no.10
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• pp.992-999
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• 1999

Due to the inherently poor adhesion strength of Cu-based leadframe/EMC(Epoxy Molding Compound) interface, popcorn-cracking phenomena of thin plastic packages frequently occur during the solder reflow process. In this study, in order to enhance the adhesion strength of Cu-based leadframe/EMC interface, brown-oxide layer was formed on the leadframe surface by immersing of leadframe sheets in hot alkaline solution, and the adhesion strength of leadframe/EMC interface was measured by using SDCB(Sandwiched Double Cantilever Beam) and SBN(Sandwiched Brazil-Nut) specimens. Results showed that brown oxide treatment of leadframe introduced fine acicular CuO crystals on the leadframe surface and improved the adhesion strength of leadframe/EMC interface. Enhancement of adhesion strength was directly related to the thickening kinetics of oxide layer. This might be due to the mechanical interlocking of fine acicular CuO crystals into EMC.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.11
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• pp.1741-1747
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• 2010

This work presents a study on the design of an economic service robot hand for tele-presence manipulators. The conceptual design of new robot hand is derived from biomimetics approach. Guided by the analysis of human arm' musculoskeletal structure, the fingers are actuated by cables and actuators in the forearm. High tension in the cables is achieved by screw-nut mechanism driven by DC motors. A set of combination springs is incorporated in each of the screw-nut mechanism for easy control of gripping force. The first prototype revealed difficulties with finger control and coupling problem between gripping force and wrist movement. The solutions to these problems have been derived from the contradiction analysis of TRIZ. The second design has been verified by tests on various objects with different weight and shape for full range of wrist motion.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.6
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• pp.1388-1393
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• 2007

The Microprocessor Based Laboratory Systems(MBL) with the remote access functional could put basic science experimental facilities together by providing a modem platform that the students can utilize simultaneously to learn basic physics, chemistry and biology, Our educator target platform combines a highly integrated 8-bit embedded Atmega128 processor and real time embedded OS (operating system), allowing plenty of headroom for follow-on basic science projects for students. The proposed MBL-NUTOS (Microprocessor Based Laboratory-NUT/OS) employed in the lab are available with internet base simulation capabilities, on public servers and students personal PCs, enabling the students to study at home and increasing the opportunity of accessing for the science laboratory facility.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5838-5842
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• 2011

The study mainly aims to explore how deterioration of motor control center, namely MCC, and vibration put impact on temperature of bus bar as well as temperature change of bolt-nut joint. The motor control center consists of three internal parts (i.e. R, S, T) which are for motor operation of high capacity. Two dimensional mechanism for measuring temperature was designed and manufactured with infrared temperature sensor. Installing it in inner motor control center enabled researcher to monitor temperature of bus bar as well as amount of change of current regularly. Temperature change of bus bar according to load was primarily examined based on a bolted joint in the experiment. It was clearly verified that temperature change of bus bar was proportional to current consumption. Therefore, installing non-contact two dimensional mechanism for measuring temperature in motor control center would be expected to prevent temperature rise owing to overload current and power outage as well as fire accident which can be triggered by poor electrical contact.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.5
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• pp.770-776
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• 2000

Pasting gelatinization of acorn flours which were prepared with soaked nut and sediment at 7.8$^{\circ}C$ for 0, 1, 2, 3 and 4 days were investigated. The peak temperature of gelatinization of untreated acorn flour (0-0) by Rapid Visco Analyzer was 73.1$^{\circ}C$, respectively, but those of flours were decreased by soaking. Peak viscosity, setback and breakdown of acorn flours were increased by soaking. In addition, consistency was increased by soaking treatment. From the result of the pasting properties, gel formation ability of acorn flour was increased with increasing soaking days of acorn nut and soaking times of sediment. The gelatinization temperature examined by X-ray diffractometry was lowered with increasing of soaking days. The observation of microstructure through a scanning electron microscope revealed that gelatinized acorn flour showed loser their original shape and structure than that of with out soaking treatment (0-0). The degree of gelatinization under the fixed temperature increased with increasing soaking days. From these results, it might be concluded that the increase of soaking days and soaking times is the factor affecting the gelatinization of acorn flour.