• Journal of the Korean Institute of Navigation
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• v.1 no.1
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• pp.27-44
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• 1977

The Maneuvering Indices of a ship are the values that decide the quantity of her motion in turning when her rudder is turned over to an angle to the starboard or the port. They consist of two kinds of indices, one of which is called index K and the other, index T. Index K decides a ship's turning ability and index T does the length of time delay of a normal turning motion after her rudder has finished the turn of an ordered angle. Generally, the values of the indices are calculated through some mathematic formulas with figures of her heading degrees recorded at a fixed time intervals during her Z test. The values of the same kind index of a ship appear differently according to the ship'sspeed, trim, rudder angle and loaded condition, etc. In this paper, the author analyzed all the amthematic formulas required to calculate the values of the indices in their forming process and examined them from the point of mathematics and dynamics and also actually figured out the values of maneuvering indices of the M.S. "HANBADA", the training ship of Korea Merchant Marine College through her Z test. The author supposed a case in which two same typed ships as the "HANBADA" in size, shape and conditions were approaching each other in meeting end on situation and each ship turned her rudder hard over to the starboard respectively when they approached to the distance of 3 times as long as the ship's length. The author worked out mathematic formulas calculating forward and transverse ship's motions within the above mentioned situation for the quantative analysis of the collision avoding action to certify whether they are in collision status or not. Applying the calculated values of the maneuvering indices of the "HANBADA" to the motion calculating formulas, the author found out the two ships were passing over each other with the clearing distance o 39m between their port quarters. With the above mentioned examinations and explanations, the author demonstrated that a ship's motion in any collision avoiding action can be shown with quantities of time and distance within reliable limit.istance within reliable limit.

• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.1
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• pp.9-20
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• 2018

Due to integrated stochastic wind and wave loads, the supporting platform of a Floating Offshore Wind Turbine (FOWT) has to bear six Degrees of Freedom (DOF) motion, which makes the random cyclic loads acting on the structural components, for instance the tower base, more complicated than those on bottom-fixed or land-based wind turbines. These cyclic loads may cause unexpected fatigue damages on a FOWT. This paper presents a study on short-term fatigue damage at the tower base of a 5 MW FOWT with a spar-type platform. Fully coupled time-domain simulations code FAST is used and realistic environment conditions are considered to obtain the loads and structural stresses at the tower base. Then the cumulative fatigue damage is calculated based on rainflow counting method and Miner's rule. Moreover, the effects of the simulation length, the wind-wave misalignment, the wind-only condition and the wave-only condition on the fatigue damage are investigated. It is found that the wind and wave induced loads affect the tower base's axial stress separately and in a decoupled way, and the wave-induced fatigue damage is greater than that induced by the wind loads. Under the environment conditions with rated wind speed, the tower base experiences the highest fatigue damage when the joint probability of the wind and wave is included in the calculation. Moreover, it is also found that 1 h simulation length is sufficient to give an appropriate fatigue damage estimated life for FOWT.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.5
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• pp.377-388
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• 2020

In this paper, the autonomous mobile robot whit only LRF sensors proposes an algorithm for avoiding moving obstacles in an environment where a global map containing fixed obstacles. First of all, in oder to avoid moving obstacles, moving obstacles are extracted using LRF distance sensor data and a global map. An ellipse-shaped safety radius is created using the sum of relative vector components between the extracted moving obstacles and of the autonomuos mobile robot. Considering the created safety radius, the autonomous mobile robot can avoid moving obstacles and reach the destination. To verify the proposed algorithm, use quantitative analysis methods to compare and analyze with existing algorithms. The analysis method compares the length and run time of the proposed algorithm with the length of the path of the existing algorithm based on the absence of a moving obstacle. The proposed algorithm can be avoided by taking into account the relative speed and direction of the moving obstacle, so both the route and the driving time show higher performance than the existing algorithm.

• Journal of Korean Academy of Nursing
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• v.34 no.6
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• pp.1117-1128
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• 2004

Purpose: This study was carried out to substantiate the application process of activity-based costing on the current cost of hospital home care (HHC) service. The study materials were documents, 120 client charts, health insurance demand bills, salary of 215 HHC nurses, operating expense, 6 HHC agencies, and 31 HHC nurses. Method: The research was carried out by analyzing the HHC activities and then collecting labor and operating expenses. For resource drivers, HHC activity performance time and workload were studied. For activity drivers, the number of HHC activity performances and the activity number of visits were studied. Result: The HHC activities were classified into 70 activities. In resource, the labor cost was 245￦per minute, operating cost was 9,570￦ per visit and traffic expense was an average of 12,750￦. In resource drivers, education and training had the longest time of 67 minutes. Average length of performance for activities was 13.7 minutes. The workload was applied as a relative value. The average cost of HHC was 62,741￦ and the cost ranged from 55,560￦ to 74,016￦. Conclusion: The fixed base rate for a visit in the current HHC medical fee should be increased. Exclusion from the current fee structure or flexible operation of traveling expenses should be reviewed.

• Bioinformatics and Biosystems
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• v.1 no.1
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• pp.46-50
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• 2006

According to the advancement of experimental techniques in molecular biology, genomic and protein sequence databases are increasing in size exponentially, and mean sequence lengths are also increasing. Because the sizes of these databases become larger, it is difficult to search similar sequences in biological databases with significant homologies to a query sequence. In this paper, we present the N-gram indexing method to retrieve similar sequences fast, precisely and comparably. This method regards a protein sequence as a text written in language of 20 amino acid codes, adapts N-gram tokens of fixed-length as its indexing scheme for sequence strings. After such tokens are indexed for all the sequences in the database, sequences can be searched with information retrieval algorithms. Using this new method, we have developed a protein sequence search system named as ProSeS (PROtein Sequence Search). ProSeS is a protein sequence analysis system which provides overall analysis results such as similar sequences with significant homologies, predicted subcellular locations of the query sequence, and major keywords extracted from annotations of similar sequences. We show experimentally that the N-gram indexing approach saves the retrieval time significantly, and that it is as accurate as current popular search tool BLAST.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.1
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• pp.153-166
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• 2010

The study analyzes the lower-trunk sizes of 7-12 year old elementary school boys and compares sizes with boys, juniors, and men for analyzing and image fit. For the study, the data of SizeKorea (2004) was analyzed. Waist, hip, and the ratio of hip-thickness to hip-width were significantly different between age groups as well as between boys, juniors, and men. In the same height group, over 145cm boys had bigger waist than juniors and smaller waists than men. Therefore, the difference of waist size and the length of leg could cause the dissatisfaction of the pant fit when tall and plump boys chose a corresponding pants size to individual height or waist. The hip-thickness of body and pants patterns were compared in the analysis of the ease of hip-thickness. Tall and plump boys will feel discomfort in the crotch area because of the insufficiency of the hip-thickness of pants. Therefore, the amount of crotch extension of individual pants should be calculated by hip size instead of using the fixed amount. The reference sizes for discriminative pants for tall and plump boys were analyzed for a better fit.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.521-524
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• 2009

This study describes aerodynamic noise of high speed wind turbine system, which is invented as a new concept in order to reduce the torque of main shaft, for design parameters of the rotor blade. For parametric study of high speed rotor aerodynamic noise, Unsteady Vortex Lattice Method with Nonlinear Vortex Correction Method is used for analysis of wind turbine blade aerodynamic and Farassat1A and Semi-Empirical are used for low frequency noise and airfoil self noise. Parameters are chord length, twist and rotational speed for this parametric research. In the low frequency range, the change of noise is predicted the same level as each parameters varies. However, in case of broadband noise of blade, the change of rotational speed makes more variation of noise than other parameters. When the geometric angles of attack are fixed, as the rotational speed is increased by 5RPM, the noise level is increased by 4dB.

• Geomechanics and Engineering
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• v.20 no.4
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• pp.359-370
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• 2020

Prestressed ground anchors are important structural elements in geotechnical engineering. Despite their widespread usage, the design process is often significantly simplified. One of the major drawbacks of commonly used design methods is the assumption that skin friction is mobilized uniformly along an anchor's fixed length, one consequence of which is that a progressive failure phenomenon is neglected. The following paper introduces an alternative design approach - a computer algorithm employing the load-transfer method. The method is modified for the analysis of anchors and combined with a procedure for the derivation of load-transfer functions based on commonly available laboratory tests. The load-transfer function is divided into a pre-failure (hardening) and a post-failure (softening) segment. In this way, an aspect of non-linear stress-strain soil behavior is incorporated into the algorithm. The influence of post-grouting in terms of radial stress update, diameter enlargement, and grout consolidation is included. The axial stiffness of the anchor body is not held constant. Instead, it gradually decreases as a direct consequence of tensile cracks spreading in the grout material. An analysis of the program's operation is performed via a series of parametric studies in which the influence of governing parameters is investigated. Finally, two case studies concerning three investigation anchor load tests are presented.

• Proceedings of the KIEE Conference
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• 1999.11a
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• pp.1-3
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• 1999

EM (ElectroMagnetic) pump is used for the purpose of transporting liquid sodium coolant with electrical conductivity in the LMR(Liquid Metal Reactor). (In the present study, pilot EM pump has been designed by using of equivalent circuit method which is commonly employed to analyze linear induction machines for the test of removal of residual heat. The length and diameter of the pump have fixed values of 840 mm and 101.6 mm each by taking account of geometrical size of circulation loop for the installation of EM pump. Flowrate versus developing pressure is related from Laithwaite's standard design formula and the characteristic analyses of developing force and efficiency are carried out according to change of input frequency. From the characteristic curve, input frequency of 13 Hz is determined as the design frequency. On the other hand, The annular air gap size of 6.05 mm is selected not to bring about too much hydraulic loss. Resultantly design analysis makes pump have the electrical input of 604 VA and the hydrodynamical capacity of 1.3 bars and 40 l/min.

• Journal of the Korean housing association
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• v.26 no.6
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• pp.147-155
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• 2015

The purpose of this study is to understand the characteristic elements of interior space which effects the basic floor plan of traditional houses, in Huizhou, CHINA. The field study for the content analysis of a interior space of traditional houses were conducted from August 16 to 21, 2015, in Xidicun & Hongcun village. The major characteristics of 'tang' interior were as follows; Firstly, all of traditional houses in a skylight that front of 'tang'. Several types of floor plan were fixed by a combination of the space layout and numbers between 'tang' and skylights. Secondly, 'Tang' is from 3,250 to 6,000 mm in width, from 3,800 to 7,800 mm in depth. All skylights are more length than 'tang' in width. So all of spacious 'tang' were very bright without any lighting fixtutes. Thirdly, the patterns of woodcuts were the major settings of interior decorations. All of a window and door, capital has a detail woodcuts that are flowers, animals, plants, peoples, vases, and geometric patterns. In the last analysis, the traditional housing designs in Huizhoui old villages were planned for family that everlasting life, made a functional and rational decision.