• Transactions of the Korean Society of Pressure Vessels and Piping
• /
• v.12 no.1
• /
• pp.62-69
• /
• 2016

Current guidance considers that uniaxially loaded specimen with a deep crack is used for the determination of the ductile-to-brittle transition temperature. However, reactor pressure vessel is under biaxial loading in real and the existence of deep crack is not probable through periodic in-service-inspection. The elastic stress intensity factor and the elastic-plastic J-integral which were used for crack-tip stress field and fracture mechanics assessment parameters. The difference of the loading condition and crack geometry can significantly influence on these parameters. Thus, a constraint effect caused by differences between standard specimens and a real structure can over/underestimate the fracture toughness, and it affects the results of the structural integrity assessment, consequentially. The present paper investigates the constraint effects by evaluating the master curve $T_0$ reference temperature of PCVN (Pre-cracked Charpy V-Notch) and small scale cruciform specimens which was designed to simulate biaxial loading condition with shallow crack through the fracture toughness tests and 3-dimensional elastic-plastic finite element analyses. Based on the finite element analysis results, the fracture toughness values of a small scale cruciform specimen were estimated, and the geometry-dependent factors of the cruciform specimen considered in the present study were determined. Finally, the transferability of the test results of these specimens was discussed.

• Fisheries and Aquatic Sciences
• /
• v.12 no.3
• /
• pp.171-178
• /
• 2009

The Perciformes include approximately 40% of all bony fishes and are the largest order of vertebrates. This order includes some of the most economically relevant marine fishes, particularly the red seabream, black seabream and rock bream. A 409 bp fragment of the cytochrome b (cyt b) gene and 403 bp and 518 bp fragments of ribosomal RNA (12S and 16S rRNA, respectively) were sequenced from five populations of natural and cultured red seabreams, natural black seabream, and natural and cultured rock breams. The mitochondrial DNA sequences were utilized for the genetic identification and population structural analyses of these three species. Phylogenetic relationships of intra- and inter-species were elucidated using three types of molecular genetic markers from three species of the order Perciformes in Korea. We noted no significant differences in the intra-specific variation of the cyt b and rRNA genes in each population however, inter-specific divergences were greater than intra-specific variation. Inter-specific variation was induced more by transition than transversion type in the cyt b and rRNA genes. The cyt b gene and rRNA genes make it possible to determine the inter-species divergence. The rRNA genes have more conserved sequences than the cyt b gene. Therefore, these genes are expected to prove useful among species belonging to the different genera or families.

• Structural Engineering and Mechanics
• /
• v.23 no.3
• /
• pp.293-308
• /
• 2006

This paper presents a complete and consistent formulation to study the seismic response of a free-standing ship supported by an arrangement of n keel blocks which are all located in a dry dock. It is considered that the foundation of the system is subjected to both horizontal and vertical in plane excitation. The motion of the system is classified in eight different modes which are Rest (relative), Sliding of keel blocks, Rocking of keel blocks, Sliding of the ship, Sliding of both keel blocks and the ship, Sliding and rocking of keel blocks, Rocking of keel blocks with sliding of the ship, and finally Sliding and rocking of keel blocks accompanied with sliding of the ship. For each mode of motion the governing equations are derived, and transition conditions between different modes are also defined. This formulation is based on a number of fundamental assumptions which are 2D idealization for motion of the system, considering keel blocks as the rigid ones and the ship as a massive rigid block too, allowing the similar motion for all keel blocks, and supposing frictional nature for transmitted forces between contacted parts. Also, the rocking of the ship is not likely to take place, and the complete ship separation from keel blocks or separation of keel blocks from the base is considered as one of the failure mode in the system. The formulation presented in this paper can be used in its entirety or in part, and they are suitable for investigation of generalized response using suitable analytical, or conducting a time-history sensitivity analysis.

• Advances in nano research
• /
• v.5 no.3
• /
• pp.193-201
• /
• 2017

ZnO, ZnO: Cu, Ga, and ZnO: Cu, Ga, Ag thin films were obtained by oxidization of ZnS and ZnS: Cu, Ga films deposited onto glass substrates by electron-beam evaporation from ZnS and ZnS: Cu, Ga targets and from ZnS: Cu, Ga film additionally doped with Ag by the closed space sublimation technique at atmospheric pressure. The film thickness was about $1{\mu}m$. The oxidation was carried out at $600-650^{\circ}C$ in air or in an atmosphere containing water vapor. Structural characteristics were investigated by X-ray diffraction (XRD) and atomic force microscopy (AFM). Photoluminescence (PL) spectra of the films were measured at 30-300 K using the excitation wavelengths of 337, 405 and 457.9 nm. As-deposited ZnS and ZnS: Cu, Ga films had cubic structure. The oxidation of the doped films in air or in water vapors led to complete ZnO phase transition. XRD and AFM studies showed that the grain sizes of oxidized films at wet annealing were larger than of the films after dry annealing. As-deposited doped and undoped ZnS thin films did not emit PL. Shape and intensity of the PL emission depended on doping and oxidation conditions. Emission intensity of the films annealed in water vapors was higher than of the films annealed in the air. PL of ZnO: Cu, Ga films excited by 337 nm wavelength exhibits UV (380 nm) and green emission (500 nm). PL spectra at 300 and 30 K excited by 457.9 and 405 nm wavelengths consisted of two bands - the green band at 500 nm and the red band at 650 nm. Location and intensities ratio depended on the preparation conditions.

• Journal of the Korean Society for Railway
• /
• v.12 no.6
• /
• pp.1049-1058
• /
• 2009

Korea's Rolling stock workshop were established with the introduction of a railway, and became the center of industrial construction in the modern age of Korea. There still exist a lot of Rolling stock workshop buildings in the Youngsan Rolling stock workshop, the representative case of Korean Rolling stock workshop, and especially the study aims to look into modern architectural properties centered on those well-preserved buildings. Korea's Rolling stock workshop were built considering the proper conditions of location such as the neighboring districts from the port to transport vehicles and materials, the place where railroad lines are centralized, the short returning distance of railroad cars for entry and departure, and had the facility layout according to the order of a working process of vehicles, and the unique structure and the section facade shape with proper functions and sizes according to each purpose. In particular, they actively adopted steel-frame structure and reinforced concrete structure, and came to have the initial characteristics of Korea's modern industrial building which is called the structural transition. Therefore, this study aims to highlight the importance of Rolling stock workshop including the Youngsan Rolling stock workshop as industrial architecture heritage in the modern age of Korea.

• Journal of the Korean Vacuum Society
• /
• v.15 no.5
• /
• pp.541-546
• /
• 2006

In this study we have investigated cathodoluminescence (CL) and structural properties of thin film $ZnGa_2O_4:Mn$ oxide phosphor by using field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), photoluminescence (PL), and cathodoluminescence. PL emission peaked at 506 nm was observed from the $ZnGa_2O_4:Mn$ phosphor target and it was attributed to the $^4T_1-^6A_1$ transition in $Mn^{2+}$ ion. The color coordinates of the emission were x = 0.09 and y = 0.67. The $ZnGa_2O_4:Mn$ films showed the excitation spectrum peaked at 294 nm by $Mn^{2+}$ ion absorption. It was found that the higher intensity of CL emission at 505 nm appears to result from the denser and closely-packed structure in $ZnGa_2O_4:Mn$ phosphor films deposited at lower pressures. The CL intensity did not show any systematic dependence on film surface roughness.

• Journal of architectural history
• /
• v.7 no.4 s.17
• /
• pp.113-130
• /
• 1998

This is a study on the ㄱ-shaped church in Korean Protestant churches. Since the Protestantism had been introduced into Korea, the style of ㄱ-shaped church was the popular style that have been fashioned in all the country of Korea. When the Protestantism was introduced into Korea, ideology which ruled over the Society of Chosun Dynasty was the Confucianism that emphasized the precepts, for example, the loyalty for the King, distinction between the sexes and so on. The Korean Protestants built the church which had ㄱ-shaped plan, so that they solved the second problem : 'distinction between the sexes'. The style of the ㄱ-shaped church is one of the characteristics which distinguish the Korean church from other nations'. Actually the ㄱ-shaped churches had been built by Korean Protestant denominations, from the early days of introducing the Protestantism till the end of 1920's. Even though most of the style of the ㄱ-shaped church is replaced with the modern style according to the extension of religious influence, luckily the ㄱ-shaped two churches : Kumsan Church(1908), Toodong Church(1929) are in existence in the Provice of ChonBuk. The purpose of this study is to make the architectural characteristics of the ㄱ-shaped church clear. This study is based on the actual survey of the ㄱ-shaped churches in existence: Kumsan Church, the Toodong Church and on the documents, photographs, interviews and so on for investigation not existing one now. The ㄱ-shaped church have the plan to separate men's side from women's with a right angle and have a pulpit which was placed at the meeting point of the front part of men's and women's sides. Generally, seen from the court, the churches have men's side in left and women's one in right. There was a screen blocking both sides in the church. But it disappeared in 1920's according to the change of the social conventionality. Most of its structural form is the Korean wooden style. The ㄱ-shaped church appeared in a transition period of the Korean church architecture.

• Journal of Families and Better Life
• /
• v.21 no.5
• /
• pp.25-40
• /
• 2003

Since Korea open her ports to the West, she had undergone a great change under the alien influences both on the macro-social and micro-social aspects. This study aims to review the korean housing, corresponding with the everyday life, during the period of transition between the 1876 - 1910 and to interpret its process of modernization and the meaning of modernity. With regards to understand the holistic human relationship and place pf living through history, this study takes the Nobert Elias' Civilization Theory as a theoretical basis. References were therefore, made to various records of foreign missionary at the time, with respect not only to macro sociological changes but also to changes of everyday life. It is of course to take physical and structural aspects of housing architecture into consideration. These works, thus, led to presuming the housing culture of said period. In order to investigate modern character of korean housing, distinctively represented by spatial structure, considerations were made to various architectural examples according to the social and residential status both in urban and rural area. As a results, this paper came to the remarks as follows; 1. It is understood, that the process of modernization is a part of the process of civilization as synthetic process. It is integrated with the change of socio-cultural aspects and everyday life. 2. Korean housing in the said period shows various different residential status and grade of civilization according to the social status as well as economical status. Modern housing was not in general yet. 3. Housing for high classes and middle classes in Seoul shows a tendency of assimilation and imitation after western model. But some examples within the housing of high classes represent its own modernity, that is based on the rationalism and equalization 4. In the housing of lower classes, it was very far from the benefits of civilization. It could analogize from the immature control of disgrace, from undevelopment of individual territory and from uncultivation of rationality in the housing space.

• Journal of the Korean GEO-environmental Society
• /
• v.9 no.1
• /
• pp.41-46
• /
• 2008

In this study, the analysis of load transition of PHC pile was performed with the static load test, which was driven in deep soft clay layer of MyungJi site in the western area of Pusan. The results of test showed that the range of unit side resistance of pile in sand layer were $7.4t/m^2$ to $23.3t/m^2$ and $6.4t/m^2$ in the soft clay layer, while the unit base resistance was $955t/m^2$ in dense silty sand layer. To select the most reasonable static bearing capacity formular, the field measured values are compared with the calculated ones from the suggested various formular. In the case of side resistance in sand layer, the suggest formular in the Structural Foundation Design Manual by KGS was most reasonable, while in clay layer Railroad Design Manual.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2004.11a
• /
• pp.246-249
• /
• 2004

While the recovery of local construction industry is picking up steam, and the number of the employed in the construction industry is on the increase, workforce supply is out of balance in its quality as well as quantity, and with economic crisis facing the country, construction and recruitment methods are in transition. In addition, rising demand in skilled workforce and a workforce in short supply have expedited wage rises and have brought broad effects on construction including productivity and construction time. Such imbalance in construction workforce supply also causes various structural changes by category. This research compares and analyzes data on annual wages of construction workforce, analyzes the state of construction workforce supply, understands recruitment structure in accordance with workforce supply conditions, and looks over characteristic changes in recruitment structure. With reflections drawn from these, this paper suggests responsive measures to future construction circumstances - changes to wages of construction workforce - as well as prospects of future construction workforce supply and measures designed for stable medium and long-term workforce supply.