• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.4
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• pp.301-308
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• 1991

In this paper, we have proposed a demodulation circuit of radio data receiver system and calculated the error probability of the digital transmitted signal corrupted under noise environment. And we have evaluated the error performance of the proposed system. The designed demodulation circuits have been implemented by using the general random logic and PLL circuits, which can be possible for the integrated circuit design of the radio data receiver system. In addition calculation of bit error rate in recovered digital signal has been accomplished ans we have confirmed that the proposed system hsa the equivalent performance with already existing ones.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.6
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• pp.794-802
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• 1994

Two species of the parasitic copepod were recovered from two Korean fishes, Lateolabrax japonicus (Cuvier and Valenciennes) and Pampus argenteus (Euphrasen) taken from Yosu Bay, Korea. The present paper contains redescription of two species of Nothobomolochus of Bomolochidae. Both species, N. lateolabracis (Yamaguti and Yamasu) and N. triceros (Basset-Smith), are newly recorded from the Korean water. N. lateolabracis and N. triceros were found on the L. japonicus and P. argenteus, respectively.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.660-663
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• 2004

This paper investigate the qualities variety of concrete using recycling water under various kinds and contents of saccaric based stabilizing agent(SSA). Fluidity had little changes with the kinds and contents of SSA. Air contents of concrete with recycled water only shows the tendency. With an increase in SSA contents, air content recovered. For bleeding properties, bleeding shows to be decreased with an increase in SSA contents. The use of recycled water accelerated the setting time. However, with an increase in SSA, setting time showed the similar level of plain concrete. SSA (Btype) had better performance in enhancing compressive strength owing to loss of air content. Although the use of recycled water increased the drying shrinkage compared with that of plain concrete, it tended to decrease with an increase in SSA.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.7
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• pp.898-904
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• 2013

In order to minimize the damage from power outage, power system should be restored quickly. In this paper, a procedure for the restoration of microgrid is proposed. After elimination of the causes of power outage, a black start algorithm is executed by considering the characteristics of distributed generation control. After all resources have been recovered to the normal state, a grid reconnecting algorithm for stable operation in grid-connected mode is performed. In order to verify the proposed algorithm, low voltage microgrid is simulated using PSCAD/EMTDC.

• Journal of Korea Multimedia Society
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• v.19 no.5
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• pp.856-864
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• 2016

Recently, HD transmission was commonplace in the case of the terrestrial broadcasting, furthermore, 4k UHD broadcasts are also being pilot and such as HD contents are common even in smart-phones. Like this, through both the content and audience are in the situation to take advantage of the HD mobile TV, only QVGA video contents are being transmitted in the terrestrial DMB broadcasting. In this paper, introduction plan of HD DMB service for activation of DMB industry will be described in terms of technical, institutional, and policy to overcome the limitations of such as DMB broadcasting. Due to the introduction of HD DMB, high quality contents will be provided to audience and the advertising revenue DMB broadcasters increased so that the market share of DMB in mobile broadcasting be recovered.

• The Transactions of the Korea Information Processing Society
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• v.7 no.6
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• pp.1874-1885
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• 2000

When a receiver of ciphertext message can not decrypt a message because he has lost his private-key, the private-key of receiver and session-key of the message should be recovered. In this paper, we developed an Encapsulation based Key Recovery System (EKRS). EKRS is a new key encapsulation based key recovery system which is characterized by secretly choice of KRA, randomized target keys. n-way recovery type, and useful for commercial key recovery. EKRS is formally specified by a pictorial model, an Extended Cryptographic Timed Petri Net (ECTPN). Secure information flow and reachability of a session-key are verified by using reachability graph of ECTPN. EKRS, executing over a Public Key Infrastructure, can be used as a security solution in Web based applications such as CALS, EC an EDI.

• Journal of the Korean Statistical Society
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• v.30 no.1
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• pp.89-98
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• 2001

Brown and Proschan(1983) introduced a model for imperfect repair. At each failure of a device, with probability p, it is repaired completely or replaced with a new device(perfect repair), and with probability 1-p, it is returned to the functioning state, but it is only recovered to its condition just prior to failure(imperfect repair or minimal repair). In this paper, we limit the number of consecutive minimal repairs by n. We find some useful properties about $\mu$$_{k}$, the expected time between the k-th and the (k+1)-st repair under he assumption that only minimal repairs are performed. Then, we assign cost to each repair and find the value of n which minimized the long-run average cost for a fixed p under the condition that the life distribution F os the device is DMRL.L.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.11 s.242
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• pp.1455-1462
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• 2005

In this paper, we intend to introduce a nonlinear finite element method based on the fully nonlinear potential flow theory in order to simulate the large amplitude sloshing flow in two-dimensional baffled tank subject to horizontally forced excitation. The free surface is tracked by a direct time differentiation scheme with the four-step predictor-corrector time integration method. The flow velocity is accurately recovered from the velocity potential by second-order least square method. In order to maintain the finite element mesh regularity and total mass, the semi-Lagrangian surface tracking method with area conservation is applied. According to the numerical formulae, we perform the parametric experiments by varying the installation height and the opening width of baffles, in order to examine the effects of baffle on the nonlinear liquid sloshing. From the numerical results, the hydrodynamic characteristics of the large amplitude sloshing are investigated.

• Economic and Environmental Geology
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• v.27 no.3
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• pp.289-294
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• 1994

This paper describes an effective utilization method of well logging data and boring cores for understanding the geology of Keoje-do area. Six holes were drilled in 1988-1989, and all rock cores were recovered. Nevertheless, seven kinds of logs were carried out in each borehole. The geologic situations of the drilling sites are accurately evaluated from a comparison between core descriptions and well logging data. Porosities and clay contents of sedimentary rocks can be calculated using the data of density and gamma-ray logs. Fractured zones are easily detected from the change in inside diameter of borehole by caliper log. Sonic, density and gamma-ray logging data clearly indicate alternated and dyke zones; the former can be detceted from an acoustic wave attenuation and a decline of compaction by sonic and density logs, the latter can be detected from the amount of potassium contents of bed rock and dyke by gamma-ray log.

• Structural Engineering and Mechanics
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• v.38 no.4
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• pp.417-428
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• 2011

This paper presents recovering of missing vibration data of a bridge transmitted from wireless sensors. Kalman filter algorithm is adopted to reconstruct the missing data analytically. Validity of the analytical approach is examined through a field experiment of a bridge. Observations demonstrate that, even a part of recovered acceleration responses is underestimated in comparison with those responses taken from cabled sensors, dominant frequencies taken from the reconstructed data are comparable with those from cabled sensors.