• The KSFM Journal of Fluid Machinery
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• v.12 no.2
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• pp.17-23
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• 2009

The program using $C/C^{++}$ which could calculate 3-D velocities from data of the flowfield obtained by a slant hot-wire has been developed. The characteristic of the exit flowfield of a circular nozzle with a curved surface was investigated. From the result, the inward-flow was verified at adjacent layers near the boundary of the exit flowfield of a circular nozzle in Id and outward-flow was sensed gradually from down-flow of Id. Similarity of the nondimensional velocity profile properlly could be obtained except near Id and the virtual origin reasonably could be obtained.

• The KSFM Journal of Fluid Machinery
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• v.16 no.4
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• pp.28-34
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• 2013

Centrifugal pump consists of a axis, a impeller and a spiral casing. The impeller is the most important component in centrifugal pump. But to minimize flow loss in discharge passage including spiral casing, the shape of spiral casing is very important also. So, to investigate the effect of shape of the spiral casing on performance curve of pump, the characteristics of spiral casing were studied through numerical analysis for centrifugal pump used on industry field. From the results the rectangular model was showed more loss than the others because of asymmetric flow field.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3138-3140
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• 1999

We propose a robust blind equalization algorithm based on dual-mode algorithm which incorporates a stop-and-go technique. The constant modulus algorithm(CMA) exhibits very slow convergence when applied to QAM signals and generates phase error. We show that convergence properties of the dual-mode MCMA can be significantly improved by simply adding a stop-and-go technique. To speed up the convergence rate, the TMA-MCMA operates in triple mode that is based on the dual-mode of the MCMA incorporated with the tap-updating control modes of the SGA.

• Animal Systematics, Evolution and Diversity
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• v.14 no.3
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• pp.243-255
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• 1998

Polychaetes from offshore waters of Geojedo Island, Korea were collected from July 1995 to J 1998. Forty species of polychaetes worms were recognized in this study. Among them, seventeen species are recorded for the first time from around Geojedo Island. Four species, Odontosyllis maculata Uschakov, 1950, Odontosyllis decta Augener, 1913, Autolytus(Regulatus) convolutus(Cognett, 1953) and Chone mollis (Bush, 1904), are turned out to be new to the Korean fauna. A brief description and figures of newly reported species in Korea are given.

• Animal Systematics, Evolution and Diversity
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• v.39 no.4
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• pp.284-288
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• 2023

In this article, a phyllidiid nudibranch which is distributed widely in the Indo-Pacific region, Phyllidia varicose Lamarck, 1801, is reported based on a specimen collected from Seopseom Islet, Jeju Island, Korea. This species is characterized by bluish-gray dorsal tubercles with a yellow cap and three distinct ridges consisting of dorsal tubercles going from the anterior to posterior region, the presence of bluish-black pigment between the dorsal ridges, and a characteristic black longitudinal stripe along the midline of the sole. In this study, we provide a key to species belonging to the genus Phyllidia discovered in Korea, the morphological descriptions, photographs, and a sequence of partial mitochondrial cytochrome c oxidase subunit I of P. varicosa. Currently, four species of the genus Phyllidia have been reported to be present in Korea, including P. varicosa.

• Korean Journal of Ichthyology
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• v.12 no.3
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• pp.215-222
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• 2000

Fish fauna of the coastal waters off Taean, Chungchyungnam-do, Korea, was investigated from May 1996 to July 1999. The specimems collected from the three localities were identified into 73 species belonging to 63 genera and 40 families. Of them the largest group was order Perciformes, comprising 35 species and 16 families, and showed 47.9% in total number of species. Chasmichthys gulosus and C. dolichognathus were commonly found from the st. 1, Sebastes schlegeli and Hexagrammos otakii, from the st. 2 and Cynoglossus joyneri, Acanthopagrus schlegeli, Pagrus majar, Chirolophis wui and Pholis fangi from the st. 3 of sampling localities. Porocottus sp. is described on the basis of 2 specimens collected from the st. 1 of sampling localities. The species was distinguished from all the other members of the genus by the following combination of characters: united dorsal fin, scales on trunk above lateral line, cirri on anterior part of lateral line.

• Korean Journal of Pharmacognosy
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• v.35 no.4 s.139
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• pp.265-270
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• 2004

The phylogenetic relationship of Polygonatum species were examined by RAPD analysis. Polygonatum Rhizoma is called 'Whang-jung', and used Polygonatum sibiricum Redoute in defined as a source plant in Korean Pharmacopoeia. Polygonati Odorati Rhizoma is called 'Wui-yu', and P. odoratum Druce var. pluriflorum Ohiwi and related species are defined is source plants in Korean Herbal Pharmacopoeia. In UPGMA analysis, Polygonum was divided into two major groups. Polygonatum sibiricum and P. stenophyllum was placed in a cluster. On the other hand, P. falcatum A. Gray was included in the other cluster comprising. P. odoratum and related species, which are used as source plants for Polygonati Odorati Rhizome.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.10
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• pp.3458-3474
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• 2014

The performance of IEEE 802.11e enhanced distributed channel access (EDCA) is influenced by several interactive parameters that make quality of service (QoS) control complex and difficult. In EDCA, the most critical performance influencing parameters are the arbitration interframe space (AIFS) and contention window size (CW) of each access category (AC). The objective of this paper is to provide a scheme for parameter control such that the throughput per station as well as the overall system throughput of the network is maximized and controllable. For this purpose, a simple and accurate analytical model describing the throughput behavior of EDCA networks is presented in this paper. Based on this model, the paper further provides a scheme in which a Pareto optimal system configuration is obtained via an appropriate CW control for a given AIFS value, which is a different approach compared to relevant papers in the literature that deal with CW control only. The simulation results confirm the effectiveness of the proposed method which shows significant performance improvements compared to other existing algorithms.

• Asian Journal of Innovation and Policy
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• v.7 no.2
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• pp.338-363
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• 2018

Mobile marketing is a brand new phenomenon. In Malaysia, marketeers do not seem to understand well enough the perceptions of consumers according to mobile marketing, especially to the mobile service users. This study analyses and evaluates any significant relationship between consumer perceptions and intentions with respect to mobile marketing, and seeks to determine the expectations, preferences, pattern and usage of the consumers of Mobile Marketing Product and Service (MMP&S). The data was obtained by convenience sampling in the big cities of Malaysia. A total of 500 questionnaires were distributed and a sample of 112 usable questionnaires was selected. The result of this research applying the Technology Acceptance Model (TAM) point to the fact that perceived usefulness, perceived ease of use, perceived innovative, social influence have a direct positive relationship with the intention to use mobile marketing. This, in turn, can shed light on the main factors determining consumer intentions to use mobile marketing that may control consumer adoption of mobile marketing.

• Asian Journal of Innovation and Policy
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• v.7 no.2
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• pp.310-337
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• 2018

Adoption of mobile learning (m-learning) is not new in Malaysian oil and gas industry, with heavy investment into research and development to train the workers. Nevertheless, the low application of learnt skills on the job remains an emergent research area where there is a missing link on the effects of m-learning and effective organisational learning and implication on its training transfer. The result of this quantitative research revealed that all variables in m-learning were found to have a positive relationship with the effective organisational learning, and there is evidence of training transfer as a mediator of the relationship between self-directed learning, training design, work environment and effective organisational learning. However, there were some discrepancies in the extend of training transfer between trainee characteristics and organisational learning. As such, some important issues emerged which challenge the importance of evaluating workers' readiness and transfer for a successful implementation of m-learning towards developing effective organisational learning.