• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.8
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• pp.3374-3383
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• 2011

In this study, numerical analyses for slamming impact phenomena have been carried out using a 2-dimensional wedge shaped structure having finite deadrise angles. Fluid is assumed incompressible and entry speed of the structure is kept constant. Geo-reconstruct(or PLIC-VOF) scheme is used for the tracking of the deforming free surface. Numerical analyses are carried out for the deadrise angles of $10^{\circ}$, $20^{\circ}$ and $30^{\circ}$. For each deadrise angle, variations are made for the grid size on the wedge bottom and for the entry speed. The magnitude and the location of impact pressure and the total drag force, which is the summation of pressure distributed at the bottom of the structure, are analyzed. Results of the analyses are compared with the results of the Dobrovol'skaya similarity solutions, the asymptotic solution based on the Wagner method and the solution of Boundary Element Method(BEM).

• Journal of Communications and Networks
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• v.3 no.4
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• pp.383-395
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• 2001

Recent measurement and simulation studies have revealed that wide area network traffic displays complex statistical characteristics-possibly multifractal scaling-on fine timescales, in addition to the well-known properly of self-similar scaling on coarser timescales. In this paper we investigate the performance and network engineering significance of these fine timescale features using measured TCP anti MPEG2 video traces, queueing simulations and analytical arguments. We demonstrate that the fine timescale features can affect performance substantially at low and intermediate utilizations, while the longer timescale self-similarity is important at intermediate and high utilizations. We relate the fine timescale structure in the measured TCP traces to flow controls, and show that UDP traffic-which is not flow controlled-lacks such fine timescale structure. Likewise we relate the fine timescale structure in video MPEG2 traces to sub-frame encoding. We show that it is possibly to construct a relatively parsimonious multi-fractal cascade model of fine timescale features that matches the queueing performance of both the TCP and video traces. We outline an analytical method ta estimate performance for traffic that is self-similar on coarse timescales and multi-fractal on fine timescales, and show that the engineering problem of setting safe operating points for planning or admission controls can be significantly influenced by fine timescale fluctuations in network traffic. The work reported here can be used to model the relevant characteristics of wide area traffic across a full range of engineering timescales, and can be the basis of more accurate network performance analysis and engineering.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.5
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• pp.506-515
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• 2011

To elucidate demersal organism community structure, abundance, and biomass by period and region in the Uljin marine ranching area, otter trawl surveys were conducted at six stations from February 2008 to December 2009. During the survey period, a total of 118 species was collected in the Uljin marine ranching area, including 76 pisces, 27 mollusca and 15 crustaceans. The average abundance of individuals was 806 ind./$m^2$ and average biomass was 31,853 g/m2. The numbers of species, species richness, individuals per area and biomass per area were higher in 2009 than in 2008. Cluster and MDS analysis, based on a Bray-Curtis similarity matrix of fourth root transformed data of number of species and individuals per area, showed division into two different groups of demersal organisms in 2008 (Group 1) and one demersal organism community in 2009 (Group 2). From cluster and MDS analysis using the similarity of the demersal community among six stations, the Uljin marine ranching area was divided into Group A (St. 2, St. 4, St. 5 and St. 6) and Group B (St. 1 and St. 3).

• Journal of the Korean Applied Science and Technology
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• v.30 no.2
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• pp.215-224
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• 2013

Recently, many cosmetic researchers have been focused on the development of high functional cosmetics including anti-wrinkle and whitening. In these studies, they couldn't afford to pay a deep attention to stable encapsulations for unstable materials and efficient drug deliveries for them. Particularly, in order to show a degree of instant effects as cosmetics, they can't also ignore moisturizing effect enough to satisfy customers just after applying and its maintenance by improving the function of skin barrier as well as above two effects. Therefore, skin analogue systems have attracted considerable attention in the view of structural and compositional similarity to intercellular membrane in stratum corneum. And, some models for skin analogue composition were developed to improve the function of skin barrier, stably encapsulate unstable materials such as retinol, vitamin B, C, E, etc., and control their skin penetration in order to show good effects as cosmetics. In this study, we suggest the new skin analogue model having the compositional similarity as well as conventional structural ones. Our skin analogue membrane(SAM) is mainly composed of ceramide/ cholesterol/phosphatidylcholin/fatty acids and its structural defects are compensated by including cholesterol amphiphile and controlling the ratio of ceramide/cholesterol. It was possible to confirm the formation of skin analogue membrane having highly-densed multilamella structure and compare them according to the change of each ratio with a polarized microscope, X-ray diffraction. More detaily, we observed their structures with a electron microscope(TEM). Finally, we dispersed them in excess of continuous water phase, observed the formation of maltese-cross liquid crystalline and measured the efficiency of drug deliveries and moisturizing effects.

• Korean Journal of Environment and Ecology
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• v.24 no.2
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• pp.93-100
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• 2010

The Taeanhaean National Park is the only seashore national park in Korea. To investigate the vegetation structure and characteristics of representative four islands such as Oedo, Janggodo, Godaedo and Gauido in Taeanhaean National Park, sixteen plots(size is $100mm^2$) were set up, and four plots were set up in each island. In the result of vegetation structure analysis of each island, Oedo and Janggodo was dominated by Pinus thunbergii community, and Godaedo was dominated by P. thunbergii-P. densiflora community and Gauido was dominated by Carpinus turczaninovii-P. densiflora community. But according to the physical environment of each island, there was a subtle difference in species composition even though the same P. thunbergii or P. densiflora community. The analysis of ordination and similarity turned out that the degree of similarity was lowest(6.58%) between Oedo and Gauido. The analysis result of species diversity and number of individuals shows that Gauido had high species diversity (2.7183) than the other islands.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.2
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• pp.58-66
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• 2023

In this study, cable tension was measured using the vibration method, and a vision-based system was applied as a sensor to measure the displacement response of a cable in a non-contact method. In the vision-based system, the camera is installed in a location that considers the target structure and the field of view of the camera. However, it can be difficult to recognize the control points required to measure the displacement response of a structure as the target structure and other structures such as vehicles may be included in the image at the intended installation location. In this study, a distorted image including a vehicle shows inaccurate results in image analysis due to the installation position of the vision-based system. Accordingly, the image including the vehicle was eliminated by calculating the similarity between the two images. To verify the validity of the method of estimating the cable tension of cable-stayed bridges using the proposed method, the vibration method was applied to cable-stayed bridges in service to measure the tension.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.4
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• pp.303-310
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• 2005

Vegetation composition and structure of forest community around Mt. Kumbong, Uiseong-Gun, Korea, were studied using a qualitative and a quantitative approach. Vegetation types and various ecological characteristics including constancy classes, relative coverage, species diversity and interspecific similarity of the major component species were analyzed. Seventy relatives were sampled in $100 m^2$ plots. Forest communities were grouped into mountain vegetation and lower-valley vegetation. The former were divided into 3 communities (Quercus mongolica, Quercus variabilis and Quercus dentata communities). The latter was an Acer mono community. Vegetation units were classified into ten groups. Woody vegetation coverage was $50\~65\%$. The lower-valley vegetation type showed from $2.06\pm0.25\;to\;2.31\pm0.26$ in the species diversity. The species showing interspecific similarity over 0.5 with Quercus mongolica appeared to be Pinus densiflora, Quercus dentata and Tilia amurensis in the tree and subtree layer, and Lindera obtusiloba, Fraxinus sieboldiana, Carex humilis and Carex siderostica in the shrub and herb layer, The species showing higher interspecific similarity with Acer mono were Cornus controversa and Ulmus davidiana in the tree and subtree layer, and Philadelphus schrenchkii and Aristolochia manshuriensis in the shrub and herb layer.

• Journal of Haehwa Medicine
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• v.21 no.1
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• pp.23-31
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• 2012

Allopathic medicine has had a lot of limits though it has maintained the status of mainstream medicine, therefore these days there has been a growing interests in traditional medicine of East Asia. According to this trend, the integration between allopathic medicine and traditional medicine has become a hot issue and the need of mutual understanding on their physiology and pathology increases. However, understanding of traditional medical theory based on ying-yang, five phases, viscera and bowels is still difficult to be accepted to allopathic medical fields. Therefore, this research tried to investigate the similarity and differences of the structures between five viscera and organs. As a result, this research found that the investigation and understanding on viscera in traditional medicine or organs in allopathic medicine has in common in some degree. However, the integration and comparison between two medicines should be done cautiously because there still are the basal different points of understanding of human structure and function.

• Journal of Ocean Engineering and Technology
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• v.16 no.4
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• pp.7-12
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• 2002

This study is aimed to find the scouring mechanism at the toe of rubble mound structures. To investigate the characteristics of scouring in front of the structure, experiments were performed with regular waves in a 2-D flume. The results of this study are as follows. 1) It can be said the characteristics of incident wave causes rolling and sliding of armour block. The difference of wave pressure on the slope, internal flow as well as settlement of armour block due to the weight cause scouring. 2) It is observed that scouring depth at the toe increased when wave height or period increased. The location of ultimate scouring and deposition depth moved seaward when wave period increased. 3) The failure of rubble mound structure was caused by waves or scouring. Failure by erosion increased with high waves and long waves. 4) Using surf-similarity parameter including characteristics of incident waves and structure, scouring and deposition pattern were found and their limit was formulated.

• International Journal of CAD/CAM
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• v.6 no.1
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• pp.125-137
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• 2006

Nowadays, many commercial CAD systems support history-based, constraint-based and feature-based modeling. Unfortunately, most systems fail during the re-evaluation phase when various kind of topological changes occur. This issue is known as "persistent naming" which refers to the problem of identifying entities in an initial parametric model and matching them in the re-evaluated model. Most works in this domain focus on the persistent naming of atomic entities such as vertices, edges or faces. But very few of them consider the persistent naming of aggregates like shells (any set of faces). We propose in this paper a complete framework for identifying and matching any kind of entities based on their underlying topology, and particularly shells. The identifying method is based on the invariant structure of each class of form features (a hierarchical structure of shells) and on its topological evolution (an historical structure of faces). The matching method compares the initial and the re-evaluated topological histories, and computes two measures of topological similarity between any couple of entities occurring in both models. The naming and matching method has been implemented and integrated in a prototype of commercial CAD Software (Topsolid).