• The Korean Journal of Ecology
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• 제13권2호
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• pp.83-92
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• 1990

Two-dimensional analysis provides a comprehensive description of the structure, scales of pattern and directional components in a spatial data set. In spectral analysisi, four functions are illustrated,; the autocorrelation, the periodogram, the R-spectrum and the $\theta$ -spectrum. The R-spectrum and $\theta$ -spectrum function respectively summarize the periodogram in term of scale of pattern and directional components. Sampling is measured in the Naejang National Park area where the Daphniphyllum trees grow. 320 contiguous (15$\times$15)m plots are located along the transect and density of all trees over DBH 3 cm recorded respectively. 12 species of vascular plant are recorded in this survey area. The trend surface of density of all plant are estimated using polynomial regression and are exhibited in 3-dimensional graph and density contour map. Transformation to the corresponding polar spectrum from the periodogram emphasized the directional components and the scales to pattern. R-spectrum corresponding to the scale of pattern of periodogram showed a large peak 15.47 in the interval 9$\theta$-spectrum corresponding to directional components have two peaks 8.28 and 11.05 in the interval $35^{\circ}\theta <45^{\circ}and 125^{\circ}\theta< <135^{\circ}, respectively. Programs to compute all the analyses described in this study was obtained from Dr. Ranshow and was translated to BASIC by the author.

• 여성건강간호학회지
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• 제21권1호
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• pp.43-54
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• 2015

Purpose: This study was conducted to identify the problem of bone health and potential influencing factors of bone mineral density (BMD) for women across the life cycle of menopause. Methods: Complex sampling design data analysis was performed on the fifth Korea National Health and Nutrition Examination Survey 2010 in order to identify the problems with bone health, BMD and its influencing factors in 3,499 women who answered the menopausal status. Women's life cycle was categorized by premenopausal, postmenopausal, and elderly. Results: 35.1% of premenopausal women, 73.3% of postmenopausal women, and 96.0% of elderly women had problems with bone health that were related to low BMD. Influencing factors of BMD were residential area, alcohol drinking, and body mass index (BMI) for premenopausal women; age, residential area, education, marital status, income, and BMI for postmenopausal women; and age, education, and BMI for elderly women. Conclusion: Problems with bone health required to be considered as a major health problem in all women regardless their life cycle. Interventions to maximize BMD need to be developed by considering its influencingfactors across the women's life cycle.

• 한국초등과학교육학회지:초등과학교육
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• 제19권1호
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• pp.145-156
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• 2000

Elementary school teachers' understandings about buoyancy were investigated through the questionnaire method. The questionnaire was composed of 4 questions on hydraulic pressure and 8 questions on buoyancy. The questions on buoyancy asked about the correlation of buoyancy with following basic concepts, density of liquid, volume of submerged object and so forth. 295 teachers on the 22 elementary schools in Busan, Yangsan and Gimhae were selected through random sampling method. The results of this study were summarized as follows: On the correlation of the magnitude and direction of hydraulic pressure with the depth of water, a large portion of the respondents had a scientific conception. But on the correlation of hydraulic pressure with density, the relatively small portion of them appeared to have a scientific conception. The respondents, on the whole, had a scientific conception about the correlation of buoyancy with density of liquid. But they seemed to have naive conceptions about the correlation of buoyancy with the volume of a submerged object and with the depth of water, the amount of water in container and the reduced amount of water by the object from container. We found that the respondents were context dependent and tended to search for solutions for the questions of buoyancy using the concept of pressure in the water. From above results, we suggested that in the would-be revised elementary science text book, the contents of pressure in the water should be introduced after the concept of weight in the water was gained.

• 한국수산과학회지
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• 제28권6호
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• pp.793-804
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• 1995

Polychaetous community survey in Tomioka Bay was carried out 5 times seasonally from May 1991 to March 1992 by quantitative grab sampling (0.05m2) at 11 stations. Based on the granulometric composition and environmental factors, a homogeneous soft bottom was found in St.5-10. The species of the polychaete were classified into three feeding groups using the Fauchald and Jumars' feeding guild system. According to polychaetous community composition data, deposit feeders predominate in sandy silt area where the silt-clay content is $60-69.3\%.$ These deposit feeders were subdivided into surface deposit feeders and subsurface deposit feeders by their living position and mode. Also, suspension feeding group comes as the third dominant group. Seasonal changes of each feeding group were described in terms of numerical density and biomass. Feeding layer and types of dominant species (Lumbrineris longifolia: surface deposit feeder; Praxillella pacifica: subsurface deposit feeder; Chone duneri; suspension filter feeder, etc.) were examined in the intact sediment core samples. Also, longterm density change among the three dominant species during 10 years was disussed.

• 한국지능시스템학회논문지
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• 제19권3호
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• pp.311-316
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• 2009

본 논문에서는 파티클 필터(Particle Filter)를 사용한 모바일 감시 로봇을 위한 실시간 움직임 추정 알고리즘을 제안한다. 파티클 필터는 몬테카를로(Monte Carlo) 샘플링 방법을 기반으로 사전분포확률(Prior distribution probability)와 사후분포확률(Posterior distribution probability)을 가지는 베이지안 조건 확률 모델(Bayesian conditional probabilities model)을 사용하는 방법이다. 그러나 대부분의 파티클 필터에서는 초기 확률밀도(Prior probability density)를 임의로 정의하여 사용하지만, 본 논문에서는 Sum of Absolute Difference (SAD)를 이용하여 초기 확률밀도를 구하고, 이를 파티클 필터에 적용하여 모바일 감시 로봇 환경에서 임의로 움직이는 물체를 강인하게 실시간으로 추정하고 추적하는 시스템을 구현하였다.

• 한국수산과학회지
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• 제36권5호
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• pp.500-508
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• 2003

The fauna associated with mussel (Mytilus galloprovincialis) beds and vertical distribution of macrobenthos were studied on the Goijeong rocky shore in Jinhae Bay, Korea. Sampling was conducted seasonally using a quadrate from January to October, 1998. In the first experiment, to reveal the community structure of macrobenthos in mussel bed, a total of 62 species $(10,690ind./m^2,\;3,802.1\;g/m^2)$ were identified, which included polychaetes $(32\;spp.,\;52.6\%),$ molluscs (16 spp.), crustaceans (10 spp.), and others. The density-dominant species were Pseudopolydora antennata, Nereis heterocirrata, Littorina brevicula and Balanus kondakovi. And the density of associated fauna was correlated with that of mussel (r=0.951, p=0.049). In the second experiment, to reveal the vertical distribution of macrobenthos on the rocky shore, ANOVA showed highly significant differences between the density of top 5 dominant species (Chthamalus challengeri, Littorina brevicula, Balanus kondakovi, Septifer virgatus and Granulilittorina exigua) and tidal levels (P=0.000). Vertical distribution of macrobnethos was characterized by Ghthamalus belt and Balanus-Septifer belt in the mussel bed.

• 한국보건간호학회지
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• 제25권2호
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• pp.266-275
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• 2011

Purpose: The study investigated the relationship of health behavior with bone mineral density (BMD) for college students. Methods: A descriptive study was done using a convenient sampling of college students (n=116) enrolled in a health-related department. Height, weight, body mass index (BMI), health behaviors recognition of subjective health, smoking, drinking, exercise, food habits, intake of calcium, and family history of fracture were measured. BMD was measured at the right forearm using Hologic lunar duel-energy X-ray absorptiometry. Data were analyzed using descriptive analysis, t-test, ANOVA and multiple linear regression. Results: The prevalence of osteopenia and osteoporosis was 41.4% and 22.4%, respectively. Significant relationships were observed between BMD of right forearm and gender, BMI, subjective health recognition, drinking, and exercise (p<.05). Results of linear regression after adjusted BMD were increased concerning subjective health recognition and regular exercise (p<.05). Conclusions: Subjective health recognition and exercise carries positive effects on BMD. We recommend for college students that healthy behaviors like proper weight, smoking cessation, regular exercise, regular food habits, and health awareness are helpful to BMD.

• Earthquakes and Structures
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• 제22권2호
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• pp.157-168
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• 2022

A moment-independent importance measure analysis approach was introduced to quantify the effects of structural uncertainty parameters on probabilistic seismic demands of simply supported girder bridges. Based on the probability distributions of main uncertainty parameters in bridges, conditional and unconditional bridge samples were constructed with Monte-Carlo sampling and analyzed in the OpenSees platform with a series of real seismic ground motion records. Conditional and unconditional probability density functions were developed using kernel density estimation with the results of nonlinear time history analysis of the bridge samples. Moment-independent importance measures of these uncertainty parameters were derived by numerical integrations with the conditional and unconditional probability density functions, and the uncertainty parameters were ranked in descending order of their importance. Different from Tornado diagram approach, the impacts of uncertainty parameters on the whole probability distributions of bridge seismic demands and the interactions of uncertainty parameters were considered simultaneously in the importance measure analysis approach. Results show that the interaction of uncertainty parameters had significant impacts on the seismic demand of components, and in some cases, it changed the most significant parameters for piers, bearings and abutments.

• 한국양식학회:학술대회논문집
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• 한국양식학회 2003년도 추계학술발표대회 논문요약집
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• pp.126-126
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• 2003

Performance of a laboratory scale closed seawater recirculating aquaculture system was evaluated. Twenty-kg Korean rockfish (130 fish) with an average body weight of 153.8 g was stocked. Over 107-day culture period, fish reached final density of 51.7 kg/m$^3$ (initial density, 33.3 kg/m$^3$) on the culture tank volume basis. On a daily basis, water addition was 3.4% of the total water volume in the system. Total ammonia nitrogen (TAN)concentrations were below 1 mg/L and nitrite nitrogen (NO$_2$-N) concentrations were within the range of 1-3 mg/L on most sampling days. TAN was removedin bead and sand filters and it was removed or produced in the sedimentation basin. Basically, NO$_2$-N was removed in the bead and sand filters while it was either removed or produced in the sedimentation basin. Nitrate nitrogen (NO$_3$-N) was produced in the bead filters and removed in the sand filter and sedimentation basin. Foam fractionator performed well in the recirculating system. The maximal daily removal values for total suspended solids (TSS) and protein were 10,9 g and 1.4 g, respectively. Whole water quality parameters were within the levels commonly recommendedfor fish culture on most of the sampling days. However, further studies are needed to evaluate the commercial feasibility of this system because of the small-scale system used in present experiment. At least, present study still provides some basic information for further studies of this kind of system.

• 한국의류산업학회지
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• 제16권1호
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• pp.43-54
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• 2014

In textile industry, needs for various weave drafts have been increased to produce high qualified textile goods. One of disadvantages of traditional textile industry was spending time and money on manual sampling. Nowadays, however, weave draft design and sampling using CAD programs reduce these consumption efficiently. Therefore, this study aimed to provide high qualified woven fabrics by weave draft designs influenced by geometric patterns. First, We analyzed geometric patterns, except for dot, stripe, and checks, in fashion collections from 2009 to 2014 S/S. Then, based on these analyses, design concepts were decided. Third, weave drafts influenced by geometric patterns were designed with weave CAD program, TEX PRO 10.0 by Youngwoo CNI inc. Forth, We simulated fabrics woven by new drafts using CAD programs, depending on fibers, yarns, density of woven, colors, and finishes. Unclassified geometric patterns would be expressed by small size patterns that influenced by retro moods, square patterns with various color variation, zigzag lines, and pieces of puzzles. Three design concepts were decided as greenness, neoclassic, and romantic chic. Thus, geometric patterns for printing were created as drafts for general looms, and one repeat of each draft were provided. According to the design concepts, we designed 13 fabrics with 4 geometric patterns weaving drafts. All Drafts were designed with CAD programs. Finally, same drafts were simulated as woven fabrics for both S/S and F/W seasons by changing each element, such as fiber, yarns, density, colors, and finishes.