• Journal of KIISE:Databases
• /
• v.30 no.1
• /
• pp.41-51
• /
• 2003

The spatiotemporal database concerns about the time-varying spatial attributes. One of the important research areas is related to the support of various location-based services in motile communication environments. It is known that database systems may be difficult to manage the accurate geometric locations of moving objects due to their continual changes of locations. However, this requirement is necessary in various spatiotemporal applications including mobile communications, traffic control and military command and control (C2) systems. In this paper we propose the $B^{st}$-tree that utilizes the concept of multi-version B-trees. It provides an indexing method (or the historical and future range query Processing on moving object's trajectories. Also we present a dynamic version management algorithm that determines the appropriate version evolution induced by the mobility patterns to keep the query performance. With experiments we .;hi)w that our indexing approach is a viable alternative in this area.

• Journal of Korean Society on Water Environment
• /
• v.32 no.1
• /
• pp.52-59
• /
• 2016

This study investigated the occurrences and succession patterns of harmful cyanobacteria, as well as environmental factors, during a 3-year period (September 2012 to August 2015) in the upper region of the Nakdong River around Sangju weir. A total of 27 cyanobacterial taxa were observed in this study, and classified into 26 species and 1 variety belonging to 11 genera, 5 families, and 3 orders. Cell density ranged from 24 to 42,001 cells/ml, with a geometric mean of 33 cells/ml, during the survey period. The dominant orders differed depending on the survey year; order Oscillatoriales in 2013, Chroococcales in 2014 and Nostocales in 2015. An Aphanizomenon bloom occurred in June 2015 at which time the highest cell density of 36,873 cells/ml was detected in the upper region of the Nakdong River, where as the Aphanizomenon spp. cell density (190-1,704 cells/ml) had been low prior to that time. An Aphanizomenon bloom also occurred at around the same time downstream in the Young River, a major inflow branch of the Nakdong River. The Aphanizomenon cell density along the Nakdong River increased markedly after joining of the YoungRiver, indicating that the Aphanizomenon bloom in the YoungRiver caused a bloom in the Nakdong River. Meteorological and environmental parameters, such as very low precipitation, higher water temperature, pH, and TP concentration, and lower TN/TP ratio, in May and June of 2015 than in 2013 and 2014 exerted marked effects on the Aphanizomenon bloom in June 2015 in the Young River.

• Journal of the Korean Home Economics Association
• /
• v.38 no.1
• /
• pp.25-38
• /
• 2000

This study focuses on the Russian Constructivist Textile Design in the post-revolutionary period, of the early 20th century. Russian textile of the time is highly valued in the west in terms of innovative changes in aesthetic directions, which has become one of the most important centers for the development of new textiles, or the origin of industrial design. Most of brilliant mass-production patterns were produced specially by the pioneers of constructivists such as Stepanova and Popova who were influenced by 'Maxism' through the Revolution regarded themselves as productivists for the proletariat. They were inspired by the avant-garde movements, which were involved with traditionalism, futuristic mechanism, stylization of nature, pure geometrical and abstract form. Early textile design was based on the relationship between the graphic methods of design and the technology because they regarded art as physical, intellectual and technical production. They created all the excitement made from the primary simplest forms of precise mathmatical shapes, such as the circle, the triangle, the rectangle and horizontle and vertical lines. These geometric design can be interpreted as the mechanization of the artists'labor, or methods in line with the technology of mass production, however partly roots in the rich tradition of Russian decorative art. On the other hand, stable crystalline construction on the surface reflect urban architectural complex, and the world of industry in graphic form. They were interested in illusion of movement, cinematic movement of vertical linear rhythms, optical formations and vibrations, by composing a multi-leveled constructions by several spatial planes, or color-field, and combining structures of several intersecting matrices, and superimposing parts of the forms on each other. All these characteristics of the Russian textile designs reflect the complex interactions between 'art and society' of Constructivist's idea and represent the traits of the epoch.

• Journal of the Korea Concrete Institute
• /
• v.19 no.4
• /
• pp.433-439
• /
• 2007

The main objective of the paper is to investigate the static behavior of a prestressed concrete (PSC) girder that has been spliced with precast box segments. A 20 m long full-scale spliced PSC girder is fabricated and tested to compare its static performance against a monolithic girder. The monolithic girder has the same geometric and material properties with respect to the spliced girder. This includes infernal strain, deflections, neutral axis position, and crack patterns for both girders. The test also consists of monitoring relative displacements occurring across the joints. Both the horizontal displacement (gap) and vertical displacement (sliding) are measured throughout the loading procedure. All results have been compared to those obtained from the monolithic girder. It has been demonstrated that the spliced girder offers close behavior with respect to the monolithic girder up to the crack load. Both girders exhibits ductile flexural failure rather than abrupt shear failure at joints.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.18 no.5
• /
• pp.35-45
• /
• 1981

An asymptotic solution of electromagnetic waves scattered by a right-angled dielectric wedge for plane wave incidence is obtained. Scattered fields are constructed by waves reflected and refracted from dielectric interfaces (geometric-optical fields) and a cylindrical wave diffracted from the edge. The edge diffracted field is obtained by adding a correction to the edge diffraction of physical optics approximation, where the correction field is calculated by solving a dual series equation amenable to simple numerical calculation. Validity of this result is assured by two limits of relative dielectric constant $\varepsilon$ of the wedge. The total asymptotic field calculated results in a Rawlins' Neumann series solution for small $\varepsilon$, and the edge diffraction pattern is shown to approach that of a perfectly conducting wedge for large $\varepsilon$. Calculated field patterns are presented and the accuracy of physical optics approximation is discussed.

• Journal of the Korean Home Economics Association
• /
• v.44 no.12
• /
• pp.9-18
• /
• 2006

A case study was conducted on the development of patient clothes designs at the Korea University Medical Center, in order to provide an example of patient clothes designs which meet the hospital identity and the demands of patients and nurses. In this study, we focused on general patient pajamas and one-piece gowns worn in the obstetrics and gynecology department. A scientific and systematic design approach consisting of the following four steps was conducted in the designing process: needs assessment, design direction establishment, design presentation, and final decision. For the first step, focused group interviews and a survey were conducted to identify the needs of the patients and nurses. According to the results of the first step, 3 fabric patterns with light, modern, rhythmic, modest and ordinary images were designed utilizing the university and hospital symbols and logotypes. Fixed forms with realistic and geometric characteristics and colors, including white, yellow, blue, grey, and pink were selected to deliver the preferred image. Each fabric pattern was made in male and female versions of the color sets. The following styles of patient clothes were made with the 3 fabric samples: general patient pajamas with a U-neckline, 9/10-length sleeves and ankle-length pants, a full-length sleeved gown with openings for breast-feeding, and a gown with a deep back-neckline and button fastening. Different sizing systems for males and females were recommended for the production.

• Fashion & Textile Research Journal
• /
• v.9 no.2
• /
• pp.145-150
• /
• 2007

Recently, active movements are occurring to reestablish our own traditional Korean images in all levels of society. One of them is about Ordinary Hanbok. Academics and business sectors are endeavoring to develop comfortable and Korean traditional Hanbok designs and popularize them as well. Based on the facts, the study focuses on developing Ordinary Hanbok designs for women by applying Korean traditional patchwork in order to present handmade, humane senses. First of all, the backgrounds, history and preference of Ordinary Hanbok are discussed through literatures and precedent studies as study methodology. Then, the study is analyzing the formative beauty of Korean traditional patchwork that contains emotions of women in the Chosun Dynasty. After that, it shows Ordinary Hanbok designs developed for women by using checks, free style, and yeoiju patterns of the fabrics dyed with clay and Chinese ink that recently attract people in particular. The results are like followings; First, the limits that excessive transformation of Hanbok may cause the lack of traditional beauty can be covered through using a variety of images of Korean traditional patchwork. Second, diverse face configuration of patchworks has very unique geometric forms so to be easily applied to modern Ordinary Hanbok designs. Third, the sewing technique of patchworks also plays a role as a design factor as important as face configuration. Fourth, utilizing fabric pieces may result in various unplanned face configuration and help resource recycling. Fifth, it is possible to coordinate Hanbok with other ordinary clothes that people normally wear on. Sixth, using patchworks images can encourage developing more active and refined designs added with traditional beauty. Seventh, natural dying and fabrics are eco-friendly, which is good for human health and environment. Finally, more studies should be done on design development based on precedent studies about Ordinary Hanbok. Also, it is important to foster social atmosphere and circumstances where people accept wearing Ordinary Hanbok as our natural culture.

• Geomechanics and Engineering
• /
• v.15 no.3
• /
• pp.869-877
• /
• 2018

The continually growing demand for underground space in dense urban cities is also driving the demand for underground highways. Building the underground highway tunnel, however, can involve complex design and construction considerations, particularly when there exists divergence or convergence in the tunnel. In this study, interaction between two asymmetric noncircular tunnels-that is, a larger main tunnel and a smaller tunnel diverging from the main tunnel, was investigated by examining the distributions of the principal stresses and the strength/stress ratio for varying geometric conditions between the two tunnels depending on diverging conditions using both numerical analysis and scale model test. The results of numerical analysis indicated that for the $0^{\circ}$, $30^{\circ}$, $60^{\circ}$ diverging directions, the major principal stress showed an initial gradual decrease and then a little steeper increase with the increased distance from the left main tunnel, except for $90^{\circ}$ where a continuous drop occurred, whereas the minor principal stress exhibited an opposite trend with the major principal stresses. The strength/stress ratio showed generally a bell-shaped but little skewed to left distribution over the distance increased from the left larger tunnel, similarly to the variation of the minor principal stress. For the inter-tunnel distance less than 0.5D, the lowest strength/stress ratio values were shown to be below 1.0 for all diverging directions ($0^{\circ}$, $30^{\circ}$, $60^{\circ}$ and $90^{\circ}$). The failure patterns observed from the model test were found to be reasonably consistent with the results of numerical analysis.

• Journal of Korean Society on Water Environment
• /
• v.21 no.4
• /
• pp.368-378
• /
• 2005

Inorganic matters originated from stone quarries and manufacturing plants could alter the ecological characteristics of adjacent aquatic systems, especially the structure and function of benthic macroinvertebrate community. In such situation, the locality of stone quarry and the quantity of inorganic matters would be important factors that determined the disturbing strength to the benthic macroinvertebrate community. Locality patterns of stone quarries were classified into 3 types in relation to the stream ecosystem; stream-proximity, upstream-inclusion and tributary-inclusion type. In the result of species:abundance analysis, stone quarry B (upstream-inclusion type) showed geometric distribution, while others showed broken-stick distribution pattern. The benthic macroinvertebrate communities closer to stone quarries showed smaller species numbers and standing crops among all types of stone quarries. However the values of species evenness index were not seriously different between controls and directly affected sites. These results indicated that the effect of inorganic disturbance would differ from those of organic pollution that induced the highly dominant state occupied by tolerant species. Number of occurred species, standing crops, community indices and biotic indices indicated that the community of upstream-inclusion type was the most seriously damaged from the inorganic disturbance, and the community would be very simple and unstable. Tributary-inclusion stone quarry heavily damaged to tributary system in biologically, but influence to the main stream seemed to be depended on the scale of main stream. Among 3 types of stone quarry localities, stream-proximity type induced the least damages to benthic macroinvertebrate community, though the degrees of damage were different along with distances between stream and stone quarry.

• Journal of the Korean Society of Costume
• /
• v.62 no.1
• /
• pp.104-119
• /
• 2012

Fashion cultural products represents cultural trend, and they are produced a lot in Korea to express the Korean culture and style. They are also tools that embody images of Korea. This study mainly focuses on the Korean traditional-patterned ornaments as fashion cultural products. Therefore, this study aims at developing a framework of consumers' attitudes and consumption behaviors about Korean traditional-patterned ornaments, examining how the characteristics are changed according to shopping orientation. For this purpose, a quantitative survey was carried out using 455 questionnaires from women in their 20s and over. The data were analyzed using frequency analysis, factor analysis, t-test, ANOVA, cluster analysis, and $x^2$-test. Findings of this study were as follows. First, half of the respondents were found to possess Korean traditional-patterned ornaments. However, consumers had positive attitudes and tend to purchase them for their own use rather than gifts, demonstrating that the potential for the market is large enough. Second, in accordance with their shopping orientation, consumers were sub-divided into four groups: trend/brand oriented, practicality/pleasure oriented, convenience oriented, and passive shoppers. The trend/brand oriented group showed highest levels of preference regarding purchase intentions of Korean traditional-patterned ornaments. This group also showed the strongest purchasing power on fashion items among the four groups. Third, this study presented animal, plant, geometric and abstract patterns to the respondents to examine their attitudes. It was found that consumers prefered plant-patterned ornaments rather than the others, demonstrating that they have stronger preference and purchase intention toward ornaments with more natural images.