• 대한치과기공학회지
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• 제37권2호
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• pp.63-67
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• 2015

Purpose: This study, it was observed on the effect of material and thickness of the mouth guard on postural balance in order to assess the influence of the use of a mouth guard. Methods: The mouth guards of 10 adults selected as the experiment subject was sorted into each of hard and soft material, and these were made as thickness of 2.0 mm, 2.5 mm, 3.0 mm, 3.5 mm by each of the material. Results: The results of this study are expected to wear the mouthguard hard to influence positive influence on the improvement of the muscle strength, static balance. Conclusion: Suggest the need for additional research on dynamic balance.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.144-144
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• 2000

Air balance hoists are widely used in handling of heavy materials in industry. Currently used air balance hoists adopt manual switches for vertical motion, thus the operator has a difficulty in operating of the switches and handling of material simultaneously. To overcome this difficulty, this study develops a weightless air-balance-hoist system using compressed air. This system memorizes the weight of material in terms of pneumatic pressure with a pneumatic circuit. Such memory of the material weight is used for achieving weightless handling of materials. Through a series of experiments, handling forces and the response of the system for various material weights are analyzed. The results show that the developed system can be used for weightless handling o( heavy materials.

• 한국환경과학회지
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• 제7권6호
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• pp.833-843
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• 1998

It is noted that the red tides and the oxygen-deficient water mass are extensively developed in Masan Bay during summer. The nutrients mass balance was calculated in Masan Bay, using the three-dimensional numerical hydrodynamic model and the material cycle model. The material cycle model was calibrated with the data obtained on the field of the study area in June 1993. The nutrients mass balance calculated by the combination of the residual currents and material cycle model results showed nutrients of surface and middle levels to be transported from the inner part to the outer part of Masan Bay, and nutrients of bottom level to be transported from outer part to inner part of Masan Bay. The uptake rate of DIN in the box A1(surface level of inner part) was found to be 337. 5mg/$m^3$ㆍday, the largest value in all 9 boxes and that of DIP was found to be 18.6mg/$m^3$ㆍday in box A1, and the regeneration rate of DIN was found to be 78.2mg/$m^3$ㆍday in the box A3(bottom level of inner part), and that of DIP was found to be 18.6mg/$m^3$ㆍday in box A1. The regenerations of DIN and DIP in the water column of the entire Bay were found to be 7.66ton/day and 760kg/day, respectively. And the releases of DIN and DIP from the sediments of the entire Bay were found to be 2.86ton/day and 634kg/day, respectively. The regeneration rate was 2.5 times as high as the release rate in DIN, and 1.2 times in DIP. The results of mass balance calculation showed not only the nutrients released from the sediments but the nutrients regenerated in water column to be important in the control and management of water quality in Masan Bay.

• 한국정밀공학회지
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• 제25권4호
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• pp.61-68
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• 2008

Of the seven base units of the international system of units, only the kilogram is still defined in terms of a material artifact. One of the experimental approaches opening the way to a new definition of the kilogram is the watt balance To improve the performance of the NPL watt balance, we need to quantify and reduce hysteresis effects in the balance knives. In this paper, we discuss the mechanical characteristics of the knife edges used in the NPL watt balance. The hysteresis mechanism is analyzed using the finite element method. It is found that the cause of hysteresis is not normal stress but shear, and the deformation of the flat, rather than the knife, is an important factor in the hysteresis mechanism. The study presented here, using finite element analysis, suggests that parameters such as material property, tip radius and knife straightness can be more important than others, such as friction coefficient, tip angle, etc.

• 한국기계가공학회지
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• 제11권1호
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• pp.7-12
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• 2012

Chemical mechanical polishing(CMP) technology is faced with the challenge of processing new electronic materials. This paper focuses on the balance between chemical and mechanical reactions in the CMP process that is required to cope with a variety of electronic materials. The material properties were classified into the following categories: easy to abrade(ETA), difficult to abrade(DTA), easy to react(ETR) and difficult to react(DTR). The chemical and mechanical balance for the representative ETA-ETR, DTA-ETR, ETA-DTR and DTA-DTR materials was considered for defect-free surfaces. This paper suggests the suitable polishing methods and examples for each electronic material.

• 한국주조공학회지
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• 제15권5호
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• pp.477-482
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• 1995

A computer simulation model of various smelting process for melting waste sand was developed by using energy and material balance concept. This model can predict the coal, flux and oxygen consumption and the volume and temperature of off-gas. The major critical variables for smelting process can be explained by using the analysis of energy and material balance. The major conclusions were as follows; 1. The most important variables for smelting process were high post-combustion ratio, high heat transfer efficiency and refractory protection technology. 2. For saving energy in this smelting process, selection of raw materials i.e coal, flux are very important, espacially using of low volatile coal is very profitable. 3. The treatment cost of waste sand is high and environmental restriction is severe, in this reason we must be concerned in the treatment of waste sand by smelting process.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2004년도 추계학술발표회 발표논문집
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• pp.1447-1448
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• 2004

As the plants are classified as a bulk facility by the Agency's safeguards criteria, the Material Balance Evaluation is a good tool to timely detect diversion that will be accomplished through the creation of defects as small as bias defects. Through all evaluations made by the Agency, it Is strongly recommended to report SRD based on both weight and enrichment, maintain the reliable MUF declaration and improve the gamma spectrometry measurement procedure. These recommendations have been now applied and are going on.

• 자원ㆍ환경경제연구
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• 제23권3호
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• pp.365-408
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• 2014

본 연구의 목적은 전통적 접근의 한계를 지적하고 물질균형 접근의 생산효율을 도입하여 두 생산효율의 차이와 2단계 효율, 오염규제의 경제성장에 미치는 영향 등을 비교하고자 함이다. 특히 상이한 국가들을 대상으로 세 그룹으로 구분하여 이들의 결과를 비교한다. 본 연구에서는 화석연료 투입물을 직접 연계된 $CO_2$와 산출물과 연결시킴으로써 보다 현실에 가까운 생산효율을 측정하였다. 전통적 생산효율과 물질균형 효율비교에서 효율의 측정치는 세부적으로 살펴보면 상당한 차이가 있다. 특히 투입물인 화석연료를 고려하지 않을 경우 저소득국은 생산효율의 성과가 나쁘고 OECD와 중고소득이 보다 좋은 성과를 보인 것으로 나타나고 있어서 현실을 제대로 반영하지 못하고 있다. 물질흐름접근에 기초할 경우 저소득국의 성과가 OECD보다 높고 환경적 요인이 경제에 미치는 영향도 보다 완화된 것으로 확인된다.

• 생약학회지
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• 제46권3호
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• pp.223-228
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• 2015

This mass balance study about ginsenoside Rg1 and Re in Red ginseng processed from Fresh ginseng is useful to understand that herbal material sources of ginseng and raw material consumption in Red ginseng preparations. In our results, total molar amounts of ginsenoside Rg1, Re and their converts in Fresh ginseng, Red ginseng, and Red ginseng extract are substantially the same. The molar amounts of ginsenoside Rg1, Re (4.324, 2.880 μmol/g) as starting materials in Fresh ginseng are kept constant as total molar amounts (sum of starting and converts) in Red ginseng (4.264, 2.596 μmol/g) and Red ginseng extract (3.389, 3.129 μmol/g). This result means that protopanaxtriol type ginsenosides and their characteristic converts are not destroyed or inflowing in Red ginseng process. Therefore, it is important for quality assurance of Red ginseng preparations that the ratio between ginsenosides Rg1, Re and these converts is kept constant.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2013년도 제46회 KOSCO SYMPOSIUM 초록집
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• pp.51-54
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• 2013

Rotary kiln reactors are frequently equipped with an axial burner with which solid burden material is directly heated. Lifters are commonly used along the length of the system to lift particulate solids and increase the heat transfer between the solid bed and the combustion gas. The material cascading from the lifters undergoes drying and reacting through direct contact with the gas stream. In this study, volume distribution of materials held within lifters was modeled according to the different lifter configuration and appropriate configuration was used for the design purpose. This was applied to the one-dimensional heat balance model of a counter-current flow reactor, which contributes to the increase of the effective contact surface, and thereby enhances the heat transfer.