• Journal of Navigation and Port Research
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• v.39 no.4
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• pp.353-360
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• 2015

The offshore oil production requires a huge amount of cost and time accompanied by multiple variables due to the peculiar nature of 'offshore'. And every process concerned is controlled by elaborate series of plans for reducing loss of lives, environment and property. This paper treats an optimization problem for offshore oil production and transportation. We present an offshore production and transportation network to define scope of the problem and construct a mixed integer linear programming model to tackle it. To demonstrate the validity of the optimization model presented, some computational experiments based on hypothetical offshore oil fields and demand markets are carried out by using MS Office Excel solver. The downstream of the offshore production and transportation network ends up with the maritime transportation problem distributing the crude oil produced from offshore fields to demand markets. We used MoDiSS(Model-based DSS in Ship Scheduling) which was built to resolve this maritime transportation problem. The paper concludes with the remark that the results of the study might be meaningfully applicable to the real world problems of offshore oil production and transportation.

• Journal of Information Management
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• v.30 no.4
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• pp.39-60
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• 1999

Digital library research has attracted much attention. While many research projects are funded by government agencies and national and international bodies, some are run by specific academic and research institutions and libraries. While some digital library projects, such as the ELINOR project in the UK, the first two phases of the eLib(Electronic Libraries) programme in the UK, and the first phase of the DLI(Digital Library Initiative) in the USA, are now over, a number of other projects are currently under-way in different parts of the world. Beginning with the definitions and characteristics of digital libraries proposed by various researchers, this paper provides brief accounts of some major digital library projects that are currently in progress, or are just completed, in different parts of the world. There follows a review of digital library research under 16 major headings. Literature for this review has been identified through a search on the LISA CD-ROM database and a Dialog search on library and information science databases, and the resulting output has been supplemented by a scan of the various Issues of D-Lib Magazine and Ariadne, and the Web sites of various organizations and institutions engaged in digital library research. The review indicates that we have learned a lot through digital library research within a short span of time. However, a number of issues are yet to be resolved. The paper ends with an indication of the research issues that need to be addressed and resolved in the near future in order to bring the digital library from the researcher's laboratory to the real life environment.

• Restorative Dentistry and Endodontics
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• v.31 no.4
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• pp.290-299
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• 2006

Objectives: The purpose of this study is to evaluate the effect of ethylene glycol analogs on modulus of elasticity and ultimate tensile strength of moist, demineralized dentin matrix. Methods: Dentin disks 0.5 mrn thick were prepared from mid-coronal dentin of extracted. unerupted, human third molars. 'I' beam and hour-glass shaped specimens were prepared from the disks, the ends protected with nail varnish and the central regions completely demineralized in 0.5M EDTA for 5 days. Ultimate tensile stress (UTS) and low strain modulus of elasticity (E) were determined with specimens immersed for 60 min in distilled water $(H_{2}O)$, ethylene glycol $(HO-CH_{2}-CH_{2}-OH)$, 2-methoxyethanol $(H_{3}CO-CH_{2}-CH_{2}-OH)$, and 1,2-dimethoxyethane $(H_{3}CO-CH_{2}-CH_{3}-OCH_{3})$ prior to testing in those same media. Modulus of elasticity was measured on the same specimens in a repeated measures experimental design. The results were analyzed with a one-way ANOVA on ranks, followed by Dunn's test at ${\alpha}\;=\;0.05$. Regression analysis examined the relationship between UTS or E and hoy's solubility parameter for hydrogen bonding $({\delta}_{h})$ of each solvent. Results: The UTS of demineralized dentin in water, ethylene glycol, 2-methoxyethanol, and 1,2-dimethoxyethane was 24 (3), 30 (5), 37 (6), and 45 (6) MPa, ${\times}$ (SD) N = 10. Low strain E for the same media were 16 (13), 23 (14), 52 (24), and 62 (22) MPa. Regression analysis of UTS vs ${\delta}_{h}$ revealed a significant $(p\;<\;0.0001,\;r\;=\;-0.99,\;R^{2}\;=\;0.98)$ inverse, exponential relationship. A similar inverse relationship was obtained between low strain E vs ${\delta}_{h}\;(p\;<\;0.0005,\;r\;=\;-0.93,\;R^{2}\;=\;0.86)$. Significance: The tensile properties of demineralized dentin are dependent upon the hydrogen bonding ability of polar solvents $({\delta}_{h})$. Solvents with low ${\delta}_{h}$ values may permit new interpeptide H-bonding in collagen that increases its tensile properties. Solvents with high ${\delta}_{h}$ values prevent the development of these new interpeptide H-bonds.

• Restorative Dentistry and Endodontics
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• v.30 no.4
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• pp.344-351
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• 2005

This study compared the microshear bond strength $({\mu}SBS)$ to end and side of enamel rod bonded by four adhesives including two total etch adhesives and two self-etch adhesives. Crown segments of extracted human molars were cut mesiodistally. The outer buccal or lingual surface was used as specimens cutting the ends of enamel rods, and inner slabs used as specimens cutting the sides of enamel rods. They were assigned to four groups by used adhesives: Group 1 (All-Bond 2), Group 2 (Single Bond), Group 3 (Tyrian SPE/One-Step Plus), Group 4 (Adper Prompt L-Pop). After each adhesive was applied to enamel surface, three composite cylinders were adhered to it of each specimen using Tygon tube. After storage in distilled water for 24 hours, the bonded specimens were subjected to ${\mu}SBS$ testing with a crosshead speed of 1 mm/minute. The results of this study were as follows: 1. The $({\mu}SBS)$ of Group 2 $(16.50\pm2.31 MPa)$ and Group 4 $(15.83\pm2.33 MPa)$ to the end of enamel prism was significantly higher than that of Group 1 $(11.93\pm2.25 MPa)$ and Group 3 $(11.97\pm2.05 MPa)$ (p<0.05). 2. The $({\mu}SBS)$ of Group 2 $(13.43\pm2.93 MPa)$ to the side of enamel prism was significantly higher than that of Group 1 $(8.64\pm1.53 MPa)$, Group 3 $(9.69\pm1.80 MPa)$, and Group 4 $(10.56 \pm1.75 MPa)$ (p<0.05), 3. The mean $({\mu}SBS)$ to the end of enamel rod was significantly higher than that to the side of enamel rod in all group (p<0.05).

• Applied Microscopy
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• v.29 no.1
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• pp.105-124
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• 1999

Histological and ultrastructural differentiations of the neuroepithelial cells in the mouse embryo during neurulation were observed. The neural plates and grooves consisted of pseudostratified columnar epithelium in the embryonic day (ED) 8 embryo were developed. In the ED 9 embryo, the neural tube was developed in all body length of embryo except both the cephalic and caudal ends. Secondary neurulation was shown at the tail bud of the ED 10 embryo. In the ED 8 embryo, the primitive streak was shown in the posterior end of the embryonic disc. The neuroepithelium, notochord and mesenchyme were well differentiated in the cephalic and cervical portions. In the ED 9 and 10 embryos, the roof plates of neural tubes were constituted of the closing of the surface ectodermal cells in the hindbrain and the neuroepithelial cells in the spinal cord. The floor plate of neural tube were consisted of the low pseudostratified columnar epithelium. The spinal motor nerve fibers were initially differentiated in the ED 10 embryo. According to the electron density of the cell and the differentiation of tell organelles, the neuroepithelial cells in the ED 9 and 10 embryos were classified into three types: dark, intermediate and light types. All types in the ED 9 embryo were observed but the dark cell in the ED 10 embryo was not done. The free ribosomes and polysomes in all neuroepithelial cells were developed. The RER and lipid droplets in the dark cell and the Golgi complex in the intermediate and light cells were observed. Many microfilaments in the cytoplasmic processes of intermediate cell and the microfilaments and microtubules in the light cell processes were observed to be well differentiated.

• Archives of design research
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• v.17 no.3
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• pp.335-342
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• 2004

Recently there have been various research activities regarding Korean traditional aesthetics. However, those researches were mainly conducted individually, partially, and periodically, which resulted in unsystematic and incomprehensive works. Therefore, it is required to orginze all the precedent research works with more systematic and objective framework. Generally speaking, all the human activities including aesthetic activity have ends, procedure and means. In other words, human being needs three key elements for realizing any thought and those three elements include contents, formal, and practical element. Element of contents is ultimate goal to accomplish as value, concept, and meaning of thought with their aims. Formal element includes methods, principles, norms, procedure, formality and style comprising of thought in order to accomplish the goal. Finally, practical element refers to specific means, tool, media, material and techniques to concretize the contents through form. Almost all of thoughts and meaning which human being tries to express consist of language. Major elements in sentence include 'subject (omissible)' , 'objects (aim)', 'predicate (formality)', 'complement (means)' and they are composed systematically and hierarchically with rules in sentence. The study compared human activity model with language structure and analyzed their implication with design (aesthetics), which made it possible to propose analytic frameworks for traditional aesthetics. In addition, the study also systematically organized the way to realize traditional aesthetic value in the present context based on the methods developed in this study.

• Journal of Astronomy and Space Sciences
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• v.19 no.4
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• pp.273-282
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• 2002

We describe some performance of the detector electronics system for the FIMS (Far-ultraviolet Imaging Spectrograph) mission. The FIMS mission to map the far ultraviolet sky uses MCP (micro-channel plate) detectors with a crossed delay line anode to record photon arrival events. FIMS has two MCP detectors, each with a ~25mm$\times$25mm active area. The unconventional anode design allows for the use of a single set of position encoding electronics for both detector fields. The centroid position of the charge cloud, generated by the photon-stimulated MCP, is determined by measuring the arrival times at both ends of the anode following amplification and external delay. The temporal response of the detector electronics system determines the readout's positional resolution for the charge centroid. High temporal resolution (<$35{\times}75$ps FWHM) and low power consumption (< 6W) were achieved for the FIMS detector electronics system.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.4
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• pp.18-29
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• 2013

A new precast concrete (PC) beam and column connection system using non-prestressed wire strands was recently developed. The system is composed of one unit of two-storied PC-column and PC-beams with U-shaped ends. The connection part of the column and beams is reinforced by deformed bars and non-prestressed wire strands in combination for the improvement of workability. Structural performance of this system was verified by several experimental studies. The purpose of this study is developing a design concept of the beam reinforced by deformed bars and non-prestressed wire strands in combination, in terms of the cross-sectional analysis, based on the preceded experiment. A minimum and maximum reinforcement ratio and the calculation formula for the strength of flexural member reinforced by reinforcements having different yield strengths are derived based on KBC2009. Under consideration existing research results for the application of high strength reinforcement bars, the design yield strength of the non-prestressed wire strand is suggested. An example for the cross section design, satisfying the serviceability requirements, demonstrates the applicability of the design concept developed in the study.

• Journal of the Institute of Convergence Signal Processing
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• v.11 no.4
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• pp.338-344
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• 2010

Both ends of welding line are often closed by wall in the welding of ship blocks. In this research, seam tracking sensing system for butt welding in the condition with wall was developed. Seam tracking sensing system measures position of carriage from wall and detects root-pass of welding line. The system consists of the laser displacement sensors and ultrasonic sensors. The laser displacement sensor reciprocal1y rotates by the motor and measures a distance from laser sensor to the welding material. The ultrasonic sensor measures a distance between welding system and walls. The distance measured by the ultrasonic sensor is used to get X(driving) position and to determine initial and end point of the weld line. Y(weaving) and Z(height) of the weld line are obtained by the distance measured by the laser displacement sensor and the orientation of the sensor. The sensing system includes the controller that is independent from the welding carriage. The seam tracking sensing system is attached to both side of welding carriage so that interference between welding torch and sensing system can be avoided during the welding. And both side sensing system minimize dead zone. Finally, developed sensing system was adhered to welding carriage and verified usefulness by experiments.

• Restorative Dentistry and Endodontics
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• v.25 no.1
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• pp.123-132
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• 2000

To overcome problems of conventional glass ionomers, resin components have been added to glass ionomers. On a continuum between glass ionomers and composites are a variety of blends, employing different proportions of acid-base and free radical reactions to bring about cure. Popular groups defined between the ends are resin-modified glass-ionomers(RMGIs), polyacid-modified composite resins(Compomers) and ionomer modified resins. These groups show different clinical properties, and in selecting these materials for a restoration, one should sufficiently understand these different setting properties. In this study, some difference in the setting characteristics of different groups of hybrid ionomers were examined. Two RMGIs (Fuji2 LC,GC / Vitremer, 3M), three Compomers (Dyract AP, Dentsply / F2000, 3M / Elan, Kerr) were involved in this study. The identification of the setting characteristics of different groups was achieved by a two-stage study. First, thermal analysis was performed by a differential scanning calorimeter, and then the hardness of each group at different depth and time were measured by a micro-hardness tester. Thermal analysis was performed to identify the inorganic filler content and to record the heat change during setting process. The setting process was progressed for each material by chemical set mode and light-cured mode. In the hardness test, samples of materials were prepared with a 6mm-diameter metal ring, and the hardness was measured at the top, and 1mm, 2.5mm, 4mm below at just after a 40 second-cure, and after 10 minutes, 24 hours, and 7 days. Statistical analysis was performed by Mann-Whitney rank sum test to assess significant differences between set modes and types of materials, and by ANOVA and T-test to evaluate the statistical meanings of data at different times and depths of each materials. Followings are findings and conclusions derived from this study. Thermal analysis; 1. Compomers show no evidence of chemical setting while RMGIs exhibit heat output during the process of chemical setting. 2. Heat of cure of RMGIs exceed Compomers. 3. The net heat output of RMGIs through light-cured mode is higher than through chemically set mode. Hardness test; 1. Initial hardness of RMGIs immediately after light cure is relatively low, but the hardness increases as time goes by. On the contrary, Comomers do not show evident increase of the hardness following time. 2. Compomers show a marked decrease of setting degree as the depth of the material increases. In RMGIs, the setting degree at different depths does not significantly differ.