• 국제초고층학회논문집
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• 제9권2호
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• pp.127-154
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• 2020

Disproportionate collapse triggered by local structural failure may cause huge casualties and economic losses, being one of the most critical civil engineering incidents. It is generally recognized that ensuring robustness of a structure, defined as its insensitivity to local failure, is the most acceptable and effective method to arrest disproportionate collapse. To date, the concept of robustness in its definition and quantification is still an issue of controversy. This paper presents a detailed review on about 50 quantitative measures of robustness for building structures, being classified into structural attribute-based and structural performance-based measures (deterministic and probabilistic). The definition of robustness is first described and distinguished from that of collapse resistance, vulnerability and redundancy. The review shows that deterministic measures predominate in quantifying structural robustness by comparing the structural responses of an intact and damaged structure. The attribute-based measures based on structural topology and stiffness are only applicable to elastic state of simple structural forms while the probabilistic measures receive growing interest by accounting for uncertainties in abnormal events, local failure, structural system and failure-induced consequences, which can be used for decision-making tools. There is still a lack of generalized quantifications of robustness, which should be derived based on the definition and design objectives and on the response of a structure to local damage as well as the associated consequences of collapse. Critical issues and recommendations for future design and research on quantification of robustness are provided from the views of column removal scenarios, types of structures, regularity of structural layouts, collapse modes, numerical methods, multiple hazards, degrees of robustness, partial damage of components, acceptable design criteria.

• Asian-Australasian Journal of Animal Sciences
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• 제30권6호
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• pp.819-827
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• 2017

Objective: Four lactic acid bacteria (LAB) strains isolated from common vetch, tall fescue and perennial ryegrass on the Tibetan Plateau were characterized, and their effects on the fermentation quality of Italian ryegrass (Lolium multiflorum Lam.) silage were studied. Methods: The four isolated strains and one commercial inoculant (G, Lactobacillus plantarum MTD-1) were evaluated using the acid production ability test, morphological observation, Gram staining, physiological, biochemical and acid tolerance tests. The five LAB strains were added to Italian ryegrass for ensiling at three different temperatures ($10^{\circ}C$, $15^{\circ}C$, and $25^{\circ}C$). Results: All isolated strains (LCG3, LTG7, I5, and LI3) could grow at $5^{\circ}C$ to $20^{\circ}C$, pH 3.0 to 8.0 and NaCl (3.0%, 6.5%). Strains LCG3, LTG7, I5, and LI3 were identified as Lactobacillus plantarum, Pediococcus acidilactici, Lactobacillus paraplantarum, and Lactobacillus casei by sequencing 16S rDNA, respectively. All LAB inoculants significantly (p<0.05) increased lactic acid (LA) contents and ratios of lactic acid to acetic acid, and reduced pH and ammonia nitrogen/total nitrogen (AN/TN) compared with uninoculated silages at various temperatures ($10^{\circ}C$, $15^{\circ}C$, and $25^{\circ}C$). Compared to the commercial inoculant G, I5, and LI3 showed similar effects on improving the silage quality of Italian ryegrass at $10^{\circ}C$ and $15^{\circ}C$, indicated by similar pH, LA content and AN/TN. Conclusion: All inoculants could improve the silage fermentation quality at various temperatures ($10^{\circ}C$, $15^{\circ}C$, and $25^{\circ}C$). At the temperature of $10^{\circ}C$ and $15^{\circ}C$, strain I5 and LI3 had similar effects with the commercial inoculant G on improving the silage quality of Italian ryegrass.

• Smart Structures and Systems
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• 제20권1호
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• pp.61-74
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• 2017

One of the most reliable and simplest tools for structural vibration control in civil engineering is Tuned Mass Damper, TMD. Provided that the frequency and damping parameters of these dampers are tuned appropriately, they can reduce the vibrations of the structure through their generated inertia forces, as they vibrate continuously. To achieve the optimal parameters of TMD, many different methods have been provided so far. In old approaches, some formulas have been offered based on simplifying models and their applied loadings while novel procedures need to model structures completely in order to obtain TMD parameters. In this paper, with regard to the nonlinear decision-making of fuzzy systems and their enough ability to cope with different unreliability, a method is proposed. Furthermore, by taking advantage of both old and new methods a fuzzy system is designed to be operational and reduce uncertainties related to models and applied loads. To design fuzzy system, it is required to gain data on structures and optimum parameters of TMDs corresponding to these structures. This information is obtained through modeling MDOF systems with various numbers of stories subjected to far and near field earthquakes. The design of the fuzzy systems is performed by three methods: look-up table, the data space grid-partitioning, and clustering. After that, rule weights of Mamdani fuzzy system using the look-up table are optimized through genetic algorithm and rule weights of Sugeno fuzzy system designed based on grid-partitioning methods and clustering data are optimized through ANFIS (Adaptive Neuro-Fuzzy Inference System). By comparing these methods, it is observed that the fuzzy system technique based on data clustering has an efficient function to predict the optimal parameters of TMDs. In this method, average of errors in estimating frequency and damping ratio is close to zero. Also, standard deviation of frequency errors and damping ratio errors decrease by 78% and 4.1% respectively in comparison with the look-up table method. While, this reductions compared to the grid partitioning method are 2.2% and 1.8% respectively. In this research, TMD parameters are estimated for a 15-degree of freedom structure based on designed fuzzy system and are compared to parameters obtained from the genetic algorithm and empirical relations. The progress up to 1.9% and 2% under far-field earthquakes and 0.4% and 2.2% under near-field earthquakes is obtained in decreasing respectively roof maximum displacement and its RMS ratio through fuzzy system method compared to those obtained by empirical relations.

• 국제초고층학회논문집
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• 제6권3호
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• pp.227-235
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• 2017

This paper describes some of the challenges for structural design of a mid-story seismic isolated high-rise building, which is located near Tokyo station, completed in 2015. The building is a mixed-use complex and encompasses three volumes: one substructure including basement and lower floors, and a pair of seismic isolated superstructures on the substructure. One is a 136.5m high Main Tower (office use), and the other is a 98.5 m high South Tower (hotel use). The seismic isolation systems are arranged in the $3^{rd}$ floor of the Main Tower and $5^{th}$ floor of the South Tower, so that we call this isolation system as the mid-story seismic isolation. The primary goal of the structural design of this building was to secure high seismic safety against the largest earthquake expected in Tokyo. We adopted optimal seismic isolation equipment simulated by dynamic analysis to minimize building damage. On the other hand, wind-induced vibration of a seismic isolated high-rise building tends to be excited. To reduce the vibration, the following strategies were adopted respectively. In the Main Tower with a large wind receiving area, we adopted a mechanism that locks oil dampers at the isolation level during strong wind. In the South Tower, two tuned mass dampers (TMDs) are installed at the top of the building to control the vibration. In addition, our paper will also report the building performance evaluated for wind and seismic observation after completion of the building. In 2016, an earthquake of seismic intensity 3 (JMA scale) occurred twice in Tokyo. The acceleration reduction rate of the seismic isolation level due to these earthquakes was approximately 30 to 60%. These are also verified by dynamic analysis using observed acceleration data. Also, in April 2016, a strong wind exceeding the speed of 25m/s occurred in Tokyo. On the basis of the record at the strong wind, we confirmed that the locking mechanism of oil damper worked as designed.

• The Korean Journal of Ecology
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• 제28권4호
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• pp.199-206
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• 2005

조류들이 휴식하고 번식하는 사주의 체계적인 관리가 요망되어 본 연구는 2003년 9월부터 2004년 8월까지 일년 동안 낙동강 하구의 최남단 동 서로 뻗어 있는 사주의 조류를 조사하였다. 조사 걸과 A지역(장자 신자도)에서 총 59종 19,148개체, B지역(사자;백합 도요등)에서 총 61종 28,391개체로 최남단 두 지역에서 총 74종 47,539개체가 관찰되었다. 각 지역별 종수와 개체수의 분류군별에서 도요 물떼새류는 두 지역 모두에서 가장 많은 종수가 관찰되었다. 개체수에서 A지역은 번식을 위해 북상하는 시기인 봄에 많은 개체가 관찰된 반면에, B지역은 월동지로 남하하는 시기인 가을에 다양한 종이 관찰되었다. 신자도 주변(A지역)에서 봄에 많은 무리가 관찰된 것은 섭금류가 번식을 위해 상단부 대마등과 장자도 주변의 갯벌에서 먹이를 섭취하고 신자도에서 휴식하기 때문인 것으로 판단된다. 이번 조사에서 나타난 결과, 최남단의 사주는 일반적인 번식지와는 달리 외부와의 접근이 차단되어 있는 천혜의 번식장소임에도 불구하고, 인간 및 포식자의 침입(집쥐, 족제비 등)이 새들에게 치명적인 타격을 입혀 먹이를 섭취하고 휴식을 취하는 것을 방해한다. 식생의 천이과정에 따라 키가 큰 초본류인 갈대가 번성하여 사주가 육역화되어 새들의 서식지와 번식지 감소를 초래한다. 따라서 새들이 사주의 나대지를 서식지와 번식지로 이용할 수 있는 이러한 지역들에 있어 갈대의 번성을 억제시켜 보존하는 방안과 인간과 침입자에 대한 체계적인 관리가 절실히 요구된다.

• 패션비즈니스
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• 제11권4호
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• pp.135-151
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• 2007

This study is human body measurement of 200 adult males in their 20s by both direct and indirect methods in order to reveal the representative male upper body types. Composition factors of body types were classified while the combination of direct-indirect measurement values was chosen. The following are the findings: 1) The analysis of direct-indirect measurement statistics showed the following results: 173.80cm (height), 69.87kg (weight), 95.58cm (chest girth), $24.67^{\circ}$ (right shoulder angle), and $9.34^{\circ}$ (shoulder width angle). 2) The factor analysis of the body types by direct measurement produced 5 factors: 1 (front length of upper body), 2 (front length of upper body), 3 (back length of upper body), 4 (circumference of upper body), and 5 (shoulders length). These factors accounted for 90.08%. Also, the cluster analysis of factor scores led to 3 types: 1 (33%, short, comparatively wide shoulders and full in the hips), 2 (25.1%, well-developed upper body in tall, inversed triangle), 3 (41%, average height, short upper body). 3) The body-type factor analysis by indirect measurement resulted in 6 factors with the explanation of 83.24%: 1 (rear upper bady thickness), 2 (front upper body width), 3 (front chest thickness), 4 (left-right shoulder angle), 5 (front width of protrusion distance in chest and shoulders), and 6 (neck's front-rear side angle).In addition, the cluster analysis of factor scores brought about 4 types: 1 (15%, well-developed front chest, beardless waist), 2 (23.5%, flat chest, with shoulder, drooping shoulders, strait neck), 3 (39%, with shoulder, curved back), and 4 (22.5%, narrow and thin, curved waist). 4) Among the 118 subjects (75%), 58 subjects commonly appearing in indirect measurement values group and direct measurement values group were chosen the representative body type group according to asterisk indexes. They had the highest frequency in direct type 3 and indirect type 3, whose combination represented the physical characteristics of the representative body types.

• Journal of Nutrition and Health
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• 제31권8호
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• pp.1283-1294
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• 1998

This study was conducted to investigate nutritional status by anthropometric meas-urement and to assess the validity of indicators for nutritional status of preschool children. Health examinations, including blood and urine tests, were done for 799 childern aged 2 to 6 years. The mean anthropometric measurements of height, weight , head circumference, and chest circumference were 90.2cm, 13.9kg, 47.7cm, 50.9cm for 2 years (n=13), 94.8cm, 15.2kg, 43.3cm, 47.0cm for 3 years(n=125), 100.7cm, 16.4kg, 46.2cm, 50.5cm for 4 years(n=272), 106.5cm, 18.1kg, 48.8cm, 53.8cm for 5 years(n=253), 113.0cm 20.4kg, 50.4cm 56.9cm for 6 years(n=136), respectively. All anthropometric measureemnts were significantly different by age and sex. The results of physical examinations excluding dental examination were normal for all studied children. Urine test results were also normal for the subjects. The most common blood type was A and the rarest one was type AB. The mean hemoglobin concentration was 11.84g/dl for boys(n=398), 11.86g/dl for girls, and 11.85kg/dl for all. The percentage of childeren whose hemoglobin concentration was less than 11.0g/dl was 21.6% for boys and 18.9% for girls. The percentage of children whose height for age, weight for age, and weight for height were in the rang of median $\pm$1 standard devication(S.D) was 71.7% , 65.6%, and 67.0% for each indicator. Obese childeren whose weight for height or weigth for age was more than median +2S.D. were 5.2% while tall children whose height for age was more than median +2S.D, were 1.8% . Past and recent nutritional status of most children(87.2%) were assessed as normal by the combination of three indicators(height for age, weight for age, weight for height). The percentate of coincidence between for height) and one assessed by anthropometric measurements (height for age, weight for age, weight for height) and one assessed by physicial was 59.6%, 69.3% and 67.8% for each indicator, respectively. The distribution of subjects by height for age was significantly different between normal and anemic groups. With these results , the nutritional status of children the studied was normal. The anthropometric measurements reflected the nutritional status of childeren relatively well. In conclusion, in comparison with biochemical meausurements anthropometric measurements are relatively simple and effective indicators for nutritional assessement of children in large health and nutrition suveys in Korea.

• 한국작물학회지
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• 제49권3호
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• pp.194-198
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• 2004

본 연구는 남서해안 간척지에서 토양 염농도(저염; 0.1%, 중염; 0.3∼0.4%)별로 쌀 품질 향상을 위한 적정 질소 시비량을 구명하기 위하여 시험한 결과를 요약하면 다음과 같다. 1.유추분화기의 초장은 질소 시비량이 많을수록 컸고, 토양염농도간에는 저염 토양에서 켰다. 2. 출수기는 저염 토양에서는 표준비인 N20kg/10a에 비해 N8-N16kg/10a까지는 같았으나 N24kg/10a에서는 1일 늦었고, 중염 토양에서는 N8-N16kg/10a 까지는 1일이 삘랐고 N24kg/10a에서는 같았으며, 토양 염농도간에는 저염 토양에서보다 중염 토양에서 4일 정도 늦었다. 3. 질소시비량이 많을수록 간장이 크고, 포장도복이 심했다. 4. 저염 토양에서 질소시비량이 많을수록 $\textrm{m}^2$ 당 립수는 많았으나 등숙비율이 낮아져 발 수량은 N12kg/10a이상에서는 유의차가 없었으며, N12kg/10a이하에서 현미의 완전미율이 높고 단백질 함량이 낮았다. 5.중염 토양에서는 질소시비량이 많을수록 $\textrm{m}^2$ 당 립수가 많고 등숙비율이 비슷하여 발 수량은 질소시비량이 많을수록 높았으나 N20kg/10a 이상에서는 유의차가 없었고, 현미의 완전미율과 단백질함량은 질소시비량간에 비슷하였다. 따라서 남서해안 간척지에서 쌀 수량 및 미질 등을 고려해 볼 때, 저염 토양에서는 N12kg/10a, 중염 토양에서는 N20kg/10a이 적당할 것으로 생각된다

• 한국약용작물학회지
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• 제10권5호
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• pp.344-352
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• 2002

본 시험은 국내 재래종 정선시호와 일본에서 도입된 삼도시호를 공시하여 시호의 품질 향상을 위해 식물생장조절제 처리가 시호의 생육 및 saikosaponin 함량에 미치는 요인들을 구명하여 얻어진 결과를 요약하면 다음과 같다. 1. 정선시호는 삼도시호보다 분지수는 적었지만 경수는 많았고, 근경이 굵으며 생근중과 건근중은 무거웠고 지근수도 많은 경향이었다. SSa 및 TSS 함량에서 정선시호가 삼도시호보다 높았고, SSc 함량에서는 정선시호가 삼도시호보다 적었다. 2. 식물생장조절제 처리시기 간에서는 6월에 처리한 것이 7월에 처리한 것보다 경수가 많았고 건근중에서는 유의적인 차이가 없었으나, 6월에 처리한 것이 7월에 처리한 것보다 SSd 함량이 높았다. 3. 식물생장조절제 처리에서 $GA_3$, 10, 50, 100 ppm, IAA 10, 50 ppm, kinetin 50 ppm 지상부 처리에서 지상부 생육을 촉진하였고, kinetin 50 ppm 처리구의 생근중과 건근중은 무처리구보다 무거웠으나 TSS 함량은 무처리구보다 낮았다. $GA_3$, 10 ppm, IAA 10 ppm처리에서 SSa, SSd 및 TSS 함량이 증가되었으며 TSS 함량은 $GA_3$, 50 및 100 ppm에서 높았다. 4. 무처리에 비하여 정선시호는 6월의 $GA_3$, 100 rpm, IAA 10 및 50 ppm, kinetin 10 ppm 처리구에서, 삼도시호는 6월의 $GA_3$, 10 ppm, IAA 10 및 100 ppm 처리구에서 생근중이나 근중은 차이가 없었지만 TSS 함량이 높아 시호생산에 가장 유리한 처리로 판단되었다.

• 한국약용작물학회지
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• 제10권5호
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• pp.317-326
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• 2002

본 시험은 국내 재래종 정선시호와 일본에서 도입된 삼도시호의 품질과 생산성 향상을 위한 적정 파종시기 및 재식밀도의 구명과 saikosaponin 생산에 기여하는 요인들을 구명하여 시호의 안정적 생산을 위한 기초 자료로 이용하고자 실험을 수행하여 얻어진 결과를 요약하면 다음과 같다. 1. 파종시기와 재식거리에 따른 시호품종간에서 정선시호는 삼도시호보다 분지수는 적었고 초장은 길었다. 1년생의 정선시호는 삼도시호보다 지상부중은 적었고 생근중과 건근중은 높았으며, 2년생에서는 정선시호와 삼도시호간에 유의적인 차이는 없었다. Saikosapon함량은 1년생 또는 2년생의 정선시호가 삼도시호보다 saikosaponin a 및 total saikosaponln함량이 높았다. 2. 파종시기에 따른 생육특성은 1년생이나 2년생의 시호 모두 4월 30일 파종구에서 경태와 분지수가 가장 굵고 많았으며, 1년생 시호에 있어서 파종시기가 빠를수록 saikosaponin c 함량이 높게 나타났다. 3. 1년생 시호는 소식일수록 초장, 경태, 분지수, 지상부중, 그리고 근경, 생근중, 건근중, 지근수 등의 생육이 촉진되었으나 2년생 시호는 소식에서 주근장만 길었다. 4. 품종, 파종시기 및 재식거리에 있어서 상호작용은 1년생 시호만이 지상부중, 주근장, 근경에서 유의적인 차이를 보였다. 1년생의 정선시호는 4월10일에 파종하면서 재식밀도를 $30{\times}15\;cm$로 재배한 것에서 지상부중, 근경 및 TSS 함량이 가장 증가되었으며, 1년생 삼도시호는 3월20일에 재식밀도를 $30{\times}10\;cm$로 재배한 것에서 지상부중과 근경이 가장 높았다.