• Animal cells and systems
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• v.8 no.1
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• pp.1-12
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• 2004

All copepodid stages and free-swimming adults of Ergasilus hypomesi Yamaguti collected from plankton samples from a brackish lake in Korea are described. The antennule remains a four-segmented appendage until copepodid V. The antenna of copepodid I carries a vestigial exopod. Sexual dimorphism first appears at copepodid IVwhose males bear primodial maxillipeds. Leg 5 also is sexually dimorphic from copepodid IV onwards, with its free segment bearing three setae in the female and two setae in the male. Morphological features of some appendages appearing during copepodid development are discussed. It is noticed that the early copepodids of the Ergasilidae show the characteristic setation on the biramous legs and proximal segments of the antennule.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.6
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• pp.886-893
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• 2000

The Characteristics of dividing the dispersed bubble, plug, and slug steam-water flow in the horizontal junctions with horizontal branches have been experimentally investigated. The experimental investigation of the separation phenomena in a $45^{\circ}$ horizontal wye with equal pipe inner diameter of 25 mm is presented to provide a data base for the development and verification of the analytical models. The phase separation and pressure distribution in the three legs of each test section are obtained through the set of measurements made in the present work. And the dependence of phase separation on different parameters, such as inlet quality and mass flux, is discussed.

• Korean Journal of Veterinary Research
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• v.30 no.4
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• pp.401-406
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• 1990

A female Holstein calf with five legs and two tails was examined macroscopically and radiographically. The external feature included two normal forelimbs, two normal hindlimbs, a normal tail and each of underdeveloped extra hindlimb and tail, which was attached to the pelvic region. The extra hindlimb consisted of an underdeveloped femur, crural meromelia, duplicated calcaneous, partially duplicated metatarsal bone, three rows of digits with hoofs. This extra hindlimb was connected to an extra os coxa. The cervical and thoracic vertebrae were fused partially. The lumbar, sacral and coccygeal vertebrae were duplicated. This calf is a dipygus associated with pygopagus parasiticus.

• Journal of Gifted/Talented Education
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• v.5 no.2
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• pp.17-36
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• 1995

The present study examined preschooler's (3-5yrs) representation and evaluation skills in a puzzle completion task. The puzzle contained panels of four children dressed for each seacon and the key to success was using a body scheme to reconstruct the panels (head, torso, legs, feet and sky on top). Baseline data (Study 1) revealed a developmental pattern of increasing bydy scheme representation along with more careful attention to season consitent construction. Spontaneous verbalization also shifted from more guiding statements (where'the head?) to move evaluative statements (this isn't right). Study 2 examined different intervention techniques for increasing representation (verbal laveling) and evaluative processes (error detection practice), along with a control group that had unassisted practice. Three year olds benefited from verbal labeling, four year olds from both types of training. Verbalizations also showed appropriated shifts toward increasing evaluation, particularly for the older children. These findings are discussed in terms of a developmental hypothesis that representation precedes evaluation skills and that training techniques should take into account the relative balance between representation and evaluation skills in the individual for the task at hand.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.102-133
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• 2015

Nature, such as plants, insects, and marine animals, uses micro/nano-textured surfaces in their components (e.g., leaves, wings, eyes, legs, and skins) for multiple purposes, such as water-repellency, anti-adhesiveness, and self-cleanness. Such multifunctional surface properties are attributed to three-dimensional surface structures with modulated surface wettability. Especially, hydrophobic surface structures create a composite interface with liquid by retaining air between the structures, minimizing the contact area with liquid. Such non-wetting surface property, so-called superhydrophobicity, can offer numerous application potentials, such as hydrodynamic drag reduction, anti-biofouling, anti-corrosion, anti-fogging, anti-frosting, and anti-icing. Over the last couple of decades, we have witnessed a significant advancement in the understanding of surface superhydrophobicity as well as the design, fabrication, and applications of superhydrophobic coatings/surfaces/materials. In this talk, the designs, fabrications, and applications of superhydrophobic surfaces for multifunctionalities will be presented, including hydrodynamic friction reduction, anti-biofouling, anti-corrosion, and anti-icing.

• Animal cells and systems
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• v.12 no.4
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• pp.249-259
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• 2008

A new laophontid copepod species, Apolethon articulatus n. sp., is described from the estuaries and salt marshes in South Korea. Apolethon articulatus is similar to the three congeneric species currently known in sharing the character combination of the elongate first endopodal segment of leg 1 with inner seta and the expansion of second endopodal segments of legs 2-4 with decrease in the number of setae on them. However, A. articulatus differs from them by the separate exopod of female leg 5 and the armature of mandibular palp with 6 setae. Description and taxonomic accounts of the new species are presented herein with detailed illustrations and SEM micrographs. As the true identity of the rarely known genus has not been clarified yet, a revised generic diagnosis is provided with a key to the species hitherto known in the genus.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.1
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• pp.150-160
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• 1995

The practical design and construction of a Stewart Platform-based unilateral universal hand-controller is presented. It is also presented that such a design concept could be implemented by developing a technical method of determining the forward kinematics of a Stewart Platform in real time. In this work, the forward kinematics of a Stewart Platform has been determined in real time using three additional displacement sensors which eliminate the computational burden of solving the forward kinematics described in nonlinear simultaneous equations. The workspace of the Stewart Platform via inverse kinematics has been analyzed numerically and used as a design guide for the determination of the mechanism dimensions such as the sizes of the upper and base platforms and the minimum and maximum lengths of the legs. The hardware of the hand-controller has been constructed and tested to demonstrate the feasibility of the design concept.

• The Journal of Korea Robotics Society
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• v.13 no.2
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• pp.97-102
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• 2018

A small and lightweight crawling robots have been actively studied thanks to their outstanding mobility and maneuverability. Those robots can navigate into more confined spaces that larger robots are unable to reach or enter such as debris and caves. In this paper, we propose a milli-scale hexapedal robot based on planar linkage design. To make this possible, two necessary conditions for successful crawling are satisfied: thrust force from the ground and aerial phase while running. These conditions are achieved through a newly developed leg design. The robot has a pair of legs and each leg has three feet. Those feet alternatively moves based on 1DOF planar linkage. This linkage is installed at each side of the robot and finally the robot shows the alternating gait and aerial phase during running. As a result, the robot runs with the crawling speed of 0.9 m/s.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.52 no.12
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• pp.689-695
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• 2003

Fault-tolerance is an important design criterion for robotic systems operating in hazardous or remote environments. This paper addresses the issue of tolerating a locked joint failure in gait planning for hexapod walking machines which have symmetric structures and legs in the form of an articulated arm with three revolute joints. A locked joint failure is one for which a joint cannot move and is locked in place. If a failed joint is locked, the workspace of the resulting leg is constrained, but hexapod walking machines have the ability to continue static walking. A strategy of fault-tolerant tripod gait is proposed and, as a specific form, a periodic tripod gait is presented in which hexapod walking machines have the maximum stride length after a locked failure. The adjustment procedure from a normal gait to the proposed fault-tolerant gait is shown to demonstrate the applicability of the proposed scheme.

• Proceedings of the ESK Conference
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• 1994.04a
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• pp.136-144
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• 1994

In this study, the human gait trajectories during normal walking were synthesized using the inverse kinematics and optimization techniques. The synthesis based on a lower extremity model consisting of a torso and two legs. Each leg has three segments: thigh, shank, foot, and is assumed to move with six degrees-of-freedom. In order to synthesize trajectiories of this redundant system, the sum of angular displacements of articulating joints was selected as an objective function to be minimized. The proposed algorithm in this study is very useful for the analysis of human gait. For the gait analysis, the trajectories of four points in each leg should be measured. However, by using the algorithm, measuring the trajectories of two points is sufficient, and thus the experimental set-up can be simplified. The predicted joint trajectories showed a good agreement with those obtained from the experiment. The statistical analysis and graphic simula- tions are also presented.