• Journal of Biosystems Engineering
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• 제25권1호
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• pp.33-38
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• 2000

This study was performed to investigate airtight storage characteristics of rough rice using airtight flexible pve container. A storage test of rough rice of 4 tonnes was carried out to determine the changes of gas composition of air in the container, grain moisture content, air temperature and relative humidity , the presence of insects ,germination rate, crack ratio , fat acidity , 1000-kernel weight, and brown rice recovery over storage period of 5 months in Suwon. Concentration of oxygen was decreased from 20% to 16% and carbon dioxide was increased of from 0.03% to 1.6%. The grain moisture content was decreased from 14.4%(w.b) to 14.1%(w.b) for 5 months storage period . Insect population levels were low but these increased after 5 months storage. Most of insects were dead, Fat acidity increased from 7.5(mg KOH/100g) to 10.2(mg KOH/100g). Other storage factors such as germination rate, brown rice recovery and 1000-kernel , and 1000-kernel weight slightly decreased and crack ratio was slightly increased. Qualities of rough rice during 5 months storage period under hemetic air conditions were maintained fairly good considering the above changes of quality factors during storage.

• Toxicological Research
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• 제20권4호
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• pp.359-363
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• 2004

This study provides more information about the potential toxicological risk of Bacillus sp. A9184 isolated from soybean paste. The evaluation was based on the guidelines of acute oral toxicity/pathogenicity for microbial pesticide and was to get more comprehensive understanding on the acute toxicity of the potential probiotic in Sprgue-Dawley rats. No dead animal was observed in rats after single oral administration with bacteria ($10^8$ CFU per animal). There were neither no treatment-related changes in clinical signs, nor changes in body weight and body temperature as com-pared with the untreated group. All tested animal showed the increase in body weight with time. The results obtained in this study suggest that the potential probiotic, Bacillus sp. A9184, is non-toxic for rat.

• 대한기계학회논문집A
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• 제35권11호
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• pp.1515-1520
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• 2011

본 연구는 유한요소해석에 의해 300톤 골리앗 크레인의 구조해석 및 평가를 하였다. 300톤 골리앗 크레인의 구조는 110m의 스판과 50m의 높이로 구성되어 있다. 크레인은 자중, 크레인의 주행 관성력, 트롤리의 주행 관성력, 풍하중, 지진하중을 받는다. 다양한 하중 조건을 입력하여 크레인의 구조 해석을 수행하였다. 크레인의 등가응력과 전체 변형량을 ANSYS Workbench에서 얻은 결과를 이용하여 크레인의 구조 안전성 여부를 판단하였다.

• 전력전자학회논문지
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• 제4권3호
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• pp.223-230
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• 1999

일반적인 슬라이딩 모드 제어기 동조 방법은 동조 피라미터의 수가 플랜트의 차수에 비례하기 때문에 고차의 프로세스에서는 어렵고, 실용적이지 못하다. Camacho(1996)은 고차의 프로세스를 시간 지연 항이 포함된 1차 프로세스로 모델링한 고정 구조 슬라이딩 모드 제어기 설계 방법을 제안하였다. 그러나 Camacho가 제안한 방법은 시간 지연 항을 1차 Taylor 급수로 근사화하는 과정에서 발생되는 근사 오차에 의해 오버슈트, 정착시간, 명령추종 등에 문제점이 있다. 본 논문에서는 이를 개선하기 위해 가중치를 고려한 새로운 형태의 Taylor 근사 기법과 이를 토대로 새로운 슬라이딩 모드 제어기 설계 방법을 제안하고자 한다.

• Advances in concrete construction
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• 제5권5호
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• pp.469-479
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• 2017

Balanced cantilever construction is extensively used in the construction of prestressed concrete (PSC) box-girder bridges. Shear-lag effect is usually considered in finished bridges, while the cumulative shear-lag effect in bridges during balanced cantilever construction is considered only rarely. In this paper, based on the balanced cantilever construction sequences of large-span PSC box-girder bridges, the difference method is employed to analyze the cumulative shear-lag effect of box girders with varying depth under the concrete segments' own weight. During cantilever construction, no negative shear-lag effect is generated, and the cumulative shear-lag effect under the balanced construction procedure is greater than the instantaneous shear-lag effect in which the full dead weight is applied to the entire cantilever. Three cross-sections of Jianjiang Bridge were chosen for the experimental observation of shear-lag effect, and the experimental results are in keeping with the theoretical results of cumulative shear-lag effect. The research indicates that only calculating the instantaneous shear-lag effect is not sufficiently safe for practical engineering purposes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권10호
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• pp.3534-3553
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• 2021

The low cost of Bluetooth technology has led to its wide usage in indoor positioning. However, some inherent shortcomings of Bluetooth technology have limited its further development in indoor positioning, such as the unstable positioning state caused by the fluctuation of Received Signal Strength Indicator (RSSI) and the low transmission frequency accompanied by a poor real-time performance in positioning and tracking moving targets. To address these problems, an indoor fusion positioning algorithm of Bluetooth technology and pedestrian dead reckoning (PDR) based on a particle filter with dynamic adjustment of weights calculation strategy (BPDW) will be proposed. First, an orderly statistical filter (OSF) sorts the RSSI values of a period and then eliminates outliers to obtain relatively stable RSSI values. Next, the Group-based Trilateration algorithm (GTP) enhances positioning accuracy. Finally, the particle filter algorithm with dynamic adjustment of weight calculation strategy fuses the results of Bluetooth positing and PDR to improve the performance of positioning moving targets. To evaluate the performance of BPDW, we compared BPDW with other representative indoor positioning algorithms, including fingerprint positioning, trilateral positioning (TP), multilateral positioning (MP), Kalman filter, and strong tracking filter. The results showed that BPDW has the best positioning performance on static and moving targets in simulation and actual scenes.

• Advances in concrete construction
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• 제11권4호
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• pp.271-284
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• 2021

This study aims to trace the response of twelve one-way sustainable concrete hollow-core slabs made by reducing cement content and using replacement of coarse aggregate by plastic aggregate. The trial mixes comprise the 25, 50, 75, and 100% replacement of natural coarse aggregate. The compressive strength of the resulting lightweight concrete with full replacement of coarse aggregate by plastic aggregate was 28 MPa. These slabs are considered to have a reduced dead weight due to using lightweight aggregate and due to reducing cross-section through using voids. The samples are tested under two verticals line loads. Several parameters are varied in this study such as; nature of coarse aggregate (natural or recycled), slab line load location, the shape of the core, core diameter, flexural reinforcement ratio, and thickness of the slab. Strain gauges are used in the present study to measure the strain of steel in each slab. The test samples were fourteen one-way reinforced concrete slabs. The slab's dimensions are (1000 mm), (600 mm), (200 mm), (length, width, and thickness). The change in the shape of the core from circular to square and the use of (100 mm) side length led to reducing the weight by about (46%). The cracking and ultimate strength is reduced by about (5%-6%) respectively. With similar values of deflection. The mode of failure will remain flexural. It is recognized that when the thickness of the slab changed from (200 mm to 175 mm) the result shows a reduction in cracking and ultimate strength by about (6% and 7%) respectively.

• 한국어병학회지
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• 제32권1호
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• pp.1-8
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• 2019

Rock bream iridovirus (RBIV) is a member of the Megalocytivirus genus that causes severe mortality to rock bream (Oplegnathus fasciatus) with characteristic clinical signs of spleen enlargement. In this study, we assessed spleen size and RBIV copy number patterns in RBIV-infected rock bream to determine lethal and safe levels of virus copy number/spleen index that may define disease progress. We found that rock bream infected with RBIV ($1.1{\times}10^7virus\;copy\;number/100{\mu}l$) and held at 29, 26, 23 or $20^{\circ}C$ exhibited significantly higher levels of spleen size compared to $17^{\circ}C$. In dead condition (100% mortality at $20{\sim}29^{\circ}C$), the spleen index ($spleen\;weight/fish\;weight{\times}100$) and virus copy number were 3.00~5.38 and $10^6{\sim}10^8/{\mu}l$, respectively. Conversely, in survived condition (0% mortality at $17^{\circ}C$), spleen index and virus copy number was as low as not-infected control ($0.34{\sim}1.22/10^0{\sim}10^1/{\mu}l$, respectively). These findings suggest that spleen index can be an indicator of disease severity of RBIV disease.

• 한국자동차공학회논문집
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• 제24권2호
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• pp.137-143
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• 2016

The fifth wheel coupler is a heavy automotive coupling structure which connects a tractor and a trailer used for heavy-duty trucks widely. It is subjected to various loads simultaneously such as rolling, pitching and yawing loads as well as coupling frictional and impact loadings. Most of existing couplers have been overdesigned and, therefore, it is necessary to reduce the dead weight to increase the fuel efficiency. The topology optimization was applied in order to find conceptual layout designs which could show major load paths and ribs locations, and then the size structural optimization was performed in order to determine the heights and thicknesses of coupler ribs with the predetermined various loading conditions for the development of a new slim coupler with a minimum weight and high enough strength and stiffness. As the results of the topology optimum design, an efficient new coupling structure for truck trailers was designed. The weight of the new fifth wheel coupler was reduced by 4.9 %, compared with the existing one, even though all strength requirements were satisfied. The fatigue test of the new coupler was performed with cyclic vertical loads (+78.4 to +235.2 kN) and horizontal loads (-91.2 to +91.2 kN) simultaneously at 1 Hz and the life of 2,000,000 cycles were achieved without failure.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2021년도 춘계학술대회
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• pp.59-59
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• 2021

Stachys sieboldii Miq. (SSM) and Acorus gramineus Soland. (AGS) have been used as traditional medicines for thousands of years in parts of Asia, including Korea, China, and Japan. Recent researches on SSM and AGS have documented a wide spectrum of therapeutic properties, including anti-inflammatory, anti-oxidative, neurodegenerative disease effects. However, the toxicity and safety of SSM and AGS, and their mixture (medicinal herber mixture, MHMIX) were not confirmed. Therefore, this study was performed to evaluate the acute toxicity and safety of SSM, AGS and MHMIX. SSM, AGS and MHMIX were orally administered at a dose of 5,000 mg/kg in ICR mice. Animals were monitored for the mortality and changes in the body weight, clinical signs and gross observation during the 14 days after dosing, upon necropsy. We also measured parameters of organ weight, clinical chemistry, and hematology. No dead and no clinical signs were found during the experiment period after administration of a single oral dose of SSM, AGS and MHMIX. There were no adverse effects on clinical signs, body weight, or organ weight and no gross pathological findings in any treatment group. Therefore, LD50 value of SSM, AGS and MHMIX may be over 5,000 mg/kg and it may have no side toxic effect to ICR mice. The results on the single-dose toxicity of SSM, AGS and MHMIX indicate that it is not possible to reach oral dose levels related to death or dose levels with any harmful side effects.