• Journal of the Korean Institute of Navigation
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• v.17 no.3
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• pp.1-14
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• 1993

The master of ship is always authorised to perform whatever acts are ordinarily necessary for the safe and proper prosecution of the voayge with regard to both ship and cargo. In other words, when a ship is away from her home port, where her business was managed, the master generally carried the owner's authority, and ordinarily he had power to enter into engagements, on their behalf, for carrying goods in the ship, or for letting her service, provided those engagements were consistent with the usual manner of employing her adopted by the owners. Accordingly he has always to decide onboard for an adequate applying of statutory law and cases whenever he acts. But the master would appear to have no such autho-rity where he can communicate with the owners without difficulty as, now-a-days, he nearly always can. This paper, therefore, intend to review some guidance of his authority in accordance with the Korean Code of Commerce as well as precedent based on it. The paper is also simply to place at the disposal of young shipmasters and those who aspire to command some legal information concerning limit of master's authority away from vessel's home port through legal commentation on the precedent, which may assist them to a better understanding of the many problems they may be faced with in the course of their ca-reers. In order to make an efficient study of legal structure concerned for shipmaster's authority, several up-to-date precedents are selected and described herein by writer's opinion for preventing unreasonable legal dispute in this field before courts in future.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.7
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• pp.1159-1169
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• 2003

This paper investigates the effects of T-stress and plastic hardening mismatch on the interfacial crack-tip stress field via finite element analyses. Plane strain elastic-plastic crack-tip fields are modeled with both MBL formulation and a full SEC specimen under pure bending. Modified Prandtl slip line fields illustrate the effects of T-stress on crack-tip constraint in homogeneous material. Compressive T-stress substantially reduces the interfacial crack-tip constraint, but increases the J-contribution by lower hardening material, J$\_$L/. For bimaterials with two elastic-plastic materials, increasing plastic hardening mismatch increases both crack-tip stress constraint in the lower hardening material and J$\_$L/. The fracture toughness for bimaterial joints would consequently be much lower than that of lower hardening homogeneous material. The implication of unbalanced J-integral in bimaterials is also discussed.

• Journal of radiological science and technology
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• v.41 no.5
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• pp.445-450
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• 2018

We aim to evaluate safety of radiation by measuring leakage dose and patient(phantom) incident dose of ZEN-PX II dental portable equipment developed by G company. Measurement for leakage dose of equipment is conducted on the top, at the bottom, on the left, on the right and at the back. Dose measurement incident on the subject with the area dosimeter when using the phantom and measurement the leakage dose of equipment when using the phantom are evaluated. Comparing the right with the highest leakage dose as a 0 cm, 25 cm, 50 cm, 75 cm and 100 cm dose measurement at the measurement height of 100 cm, 64.2 uR was reduced to 47.3 uR in the senser mode 0.32sec. Even in film mode it was measured at 414.4 uR and about 27% lower at 162.6 uR. As the result of this study, when the irradiation time is 2 sec the right side dose is 290.5 uR and sensor mode is 0.32 sec the right side dose is 64.2 uR.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.1
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• pp.84-95
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• 1994

The effects of punch and blank shapes in the rectangular cup drawing process are examined experimentally to improve the formabilities. For this purpose, three blank shapes which are h-bl., G-bl., and T-bl., and five punch shape factors which are the ratios of two adjacent side lengths in rectangular cross section are adopted. The constructing methods of the three blank shapes are as follows. The h-bl. is designed by slip-line theory, and the G-bl. is selected for the similar shape to the punch. The T-bl. is obtained by the drawing method which is introduced in the technical references. The five punch shape factors are selected for length/width=1, 1.25, 1.5, 1.75 and 2. The experimental procedures are performed for all the above forming conditions to investigate and compare the formabilities. As a result, it is verified experimentally that the rectangular cups drawn by the h-bl. are more ideal than those drawn by G-bl. and T-bl.. They have not only higher limiting drawing ratio, more uniformity in drawn cup heights and more ideal thickness distributions, but also need relatively less maximum drawing forces.

• Journal of the Korean Society for Marine Environment & Energy
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• v.2 no.1
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• pp.90-101
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• 1999

This paper is concerned with the design of automatic ship maneuvering system including automatic path tracking controller and automatic berthing controller. The optimal control technique is employed to design the automatic path tracking controller, which is based on the linearized equations of ship motion. The numerical example shows that the automatic path tracking controller is capable of tracking the line between way points which are determined by pilot a priori. The decentralized control technique is employed to design the automatic berthing controller. In addition to the automatic path tracking controller, the fuzzy logic controller is used to control the forward speed. The numerical example shows that the automatic berthing controller can be successfully implemented.

• Analytical Science and Technology
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• v.5 no.4
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• pp.367-372
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• 1992

In order to measure the energy spectrum of a radioactive neutron source, the pulse shape discrimination (PSD) system with organic scintillator, NE-213, was characterized by using some of the gamma ray sources and neutron source, Am-Be. The figure of merit of the rise time spectrum of AmBe source measured by this system was about 1.13. This value agrees well with the value of 1.3 which is measured for monoenergetic source, $^{12}C(d,\;n)^{13}N$. The results of present experiment for performance test of NE213-PSD system will provide the useful technique to measure the spectrum of neutron-gamma mixed field and to establish the neutron energy spectrum and flux density standards.

• Nuclear Engineering and Technology
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• v.5 no.2
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• pp.83-86
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• 1973

The protective effects of acetylbenzoylaconine, 2-aminoethylisothiouronium bromide hydrobromide, $\beta$-mercaptoethylamine HCI, and L-thiazolidine-4-carboxylic acid were studied on the white male mice, aged 5-6 weeks. The toxicity test of acetylbenzoylaconine revealed that the LD$_{50}$ was 2.5 mg/kg of body weight. After the administration of test substances, mice were irradiated with whole body dose of 800 rad by the Co-60 source. Observing the number of surviving mice for 30 days, the survival coefficients for the test groups were calculated and with these the protective coefficients against radiation injury, PCR, were also calculated. The PCR values are 2.24, 2.95, 2.78, and 1.23 for acetylbenzoylaconine, 2-aminoethylisothiouronium bromide hydrobromiide, $\beta$-mercaptoethylamine HCI, and L-thiazolidine-4-carboxylic acid respectively. These values reveal that the acetylbenzoylaconine has protective potency against radiation injury on white male mice.

• Journal of the Korean Institute of Telematics and Electronics
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• v.21 no.4
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• pp.72-77
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• 1984

A placement program in LSI layout is developed and the results of test are discussed in this paper. In order to achieve 100% wiring, this paper introduces, as a virtual routing method, an algorithm which is close to the real routing. This algorithm is reflected to calculate the channel density. An object function is introduced to achieve minimization of total wire length, number of cuts, and maximum channel density simultaneously. The time complexity for the proposed virtual routing algorithm is O(n2). The time required for the algorithm is very short. This algorithm represents the routing state which is close to minimum wire length. So this algorithm is very proper to the application of placement problem. An auto-placement program is developed by the use of this algorithm. The efficiency of the proposed algorithm is shown in the test of the developed program.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.4
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• pp.109-117
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• 1993

Force balance method is employed to predict forging information such as forging load, tool pressure and normal stress at the surface of tangential velocity discontinuity. The incipient stages of deformation for the plane strain forging of rectangular billets in V-shaped dies of different semi-angles are analysed. To construct an approximate model for the analysis of deformation by the force balance method in the incipient deformation stages, slip-line field is used. When the deformation mode by slip-line method is the same as that by force balance method, the slip-line method and the force balance method give identical solutions. The effects of die angle, coefficient of friction, billet geometries and deforma- tion characteristics are also investigated. In order to verify the validity of force balance analysis, the rigid-plastic finite element simulation for the various forgig parameters are performed and performed and find to be in good agreement.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.3 s.246
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• pp.269-278
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• 2006

This paper proposes slip line fields for bending of unequally notched specimens in plane strain that have a sharp crack in one side and a sharp V-notch in the other side. Depending on the back angle, two slip line fields are proposed, from which the limit moment and crack tip stress fields are obtained as a function of the back angle. Excellent agreement between slip line field solutions with those from detailed finite element limit analysis based on non-hardening plasticity provides confidence in the proposed slip line fields. One interesting point is that, for the unequally notched specimen, the difference between the crack tip triaxial stress for tension and that for bending increases significantly with increasing the back angle. This suggests that such a specimen could be potentially useful to investigate the crack tip constraint effect on fracture toughness of materials. In this respect, the possibility of designing a new toughness testing specimen with varying crack tip constraint is discussed.