• The Safety technology
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• no.158
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• pp.12-14
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• 2011

서울 관악구 신림동에 위치한 강남순환도시고속도로 6-1공구, 이곳은 연장 155m의 터널을 뚫는 현장으로, 시공 초기인 현재는 발파작업이 한창 진행되고 있다. 발파작업은 다량의 폭약이 수시로 사용되는 만큼 위험성이 상당히 높은 공정 중 하나다. 하지만 이곳 현장의 모습을 보면 정말 위험공정이 맞나하는 의구심이 들게 된다. 그만큼 안전관리가 철저하다는 얘기다. 수차례에 걸친 시험발파를 통해 진동과 소음을 최소화한 발파작업이 이뤄지고 있으며, 작업 시 대응절차에 나서는 근로자들의 모습도 일사불란하기 그지없다. '안전'으로 터널공사의 새로운 교과서를 만들겠다는 이곳 현장을 찾아가 그들만의 특별한 안전활동을 살펴봤다.

• Magazine of RCR
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• v.15 no.4
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• pp.58-63
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• 2020

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.115-116
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• 2023

In this study, it was confirmed whether kaolin can play a role as a bed materials and a role in reducing clinkers by using kaolin with a bed materials for the purpose of removing clinkers such as slagging and fouling generated in circulating fluidized bed combustion furnaces using solid fuel.

• 주류산업
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• v.24 no.1
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• pp.1-8
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• 2004

각종 통계 지표로 볼 때 한국경제는 지난해 3분기중 바닥을 치고 회복궤도에 접어든 것으로 판단된다. 우선 경기사이클을 나타내는 대표적 지표인 동행지수 순환변동치가 작년 7월에 바닥을 치고 다시 상승국면으로 진입한 점이다. 동행지수는 산업생산, 제조업가동률, 도소매판매, 수출액, 수입액, 비농가취업자수, 건설기성액 등 7개 지표를 하나로 묶어 실물경기 흐름을 파악하기 위해 작성하는 지표다. (중략)

• The Optical Journal
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• s.136
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• pp.42-44
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• 2011

부품소재산업의 발전은 산업 간 연관관계를 강화함으로써 수출과 내수 간 선순환 구조를 정착시키고, 중소기업의 발전을 통해 대기업-중소기업 간 동반성장과 일자리 창출, 내수기반의 확대에도 기여할 수 있다. 개방경제에서 일국의 국제분업 위상과 이득은 국가 간 상대적인 관계속에서 형성된다는 점에서, 개방 경제의 시각에서 본 정부의 역할은 폐쇄경제의 시각에서보다 더 크고 중요하다. 또한 경기침체기에는 부품소재에 대한 민간의 R&D투자 역량이 약화되는 경향이 있으므로 R&D투자를 위한 정부의 역할이 더욱 중요하다. 이 모두가 '부품소재특별조치법'이 연장돼야 할 이유다.

• The Journal of the Korea Contents Association
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• v.14 no.8
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• pp.431-441
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• 2014

In order to maximize customer's satisfaction, high-value service needs to be created by reducing service delivery errors and miscommunications. Employee's job rotation experience will help them to reduce errors and develop their career. The purpose of this study is to examine the effect of job rotation on employability and subjective career satisfaction. The results clarifies the hotel's job rotation system and examine the relationship among job rotation, employability and subjective career satisfaction. Taking samples from full-time workers in hotel, total 370 participants were used in the analysis. The SEM approach was used to analysis the data with AMOS 20.0. The results show that job rotation has a positive influence on employability and subjective career satisfaction. Moreover, employability has a partial mediation effect between job rotation and subjective career satisfaction. Therefore, the study contributes to generate theoretical and practical implications in hospitality industry.

• Journal of the Korea Concrete Institute
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• v.28 no.3
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• pp.357-363
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• 2016

To solve the exhaustion problem of natural aggregate which were create the high value in construction and environmental industry, recycled aggregates have considerable benefits than other materials. However, even though many researches have been conducted with recycled aggregates, building structures with recycled aggregated are rarely constructed because it has lower quality than natural aggregates have. In this study, mechanical and strain properties of recycled aggregates concrete containing steel fibers have been reviewed in order to complement performance of recycled aggregates concrete. As results, recycled aggregates concrete showed lower compressive strength and elastic modulus than plain concrete. But, recycled aggregates concrete containing steel fibers showed equivalent performance with plain concrete. In review of drying shrinkage and creep coefficient, recycled aggregates concrete containing steel fibers showed similar behavior with plain concrete in the range of 0.5 Vol.% fiber content rate by internal restraint effect, moisture transport restraint effect and strength enhancement effect of steel fiber. Therefore, it is considered that mixing steel fibers with concrete is the effective method as a active application plan for recycled aggregates.

• Journal of Korea Society of Waste Management
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• v.35 no.8
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• pp.721-730
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• 2018

We investigated the effects of heavy metals in cement in the last 3 years and the amount of waste in the cement manufacturing process. The result shows that the average $Cr^{6+}$ content in cement products is controlled at 10 mg/kg. Cu and Pb have lower detection tendency in white cement than in ordinary portland cement. In addition, heavy metals such as Cd show a certain level of detection regardless of the input wastes. Copper slag and phosphate gypsum are the main influencing factors on the heavy metals in cement products. In auxiliary fuels, plastics waste and wood waste are considered to affect heavy metals in cement products. Alternative raw materials are considered to be affected by the alternative raw materials managed as byproducts. In the case of supplementary fuels, auxiliary fuels managed as waste instead of auxiliary fuels managed as byproducts affect the heavy metals in cement. This study examined the input amount without considering the heavy metals in each waste. Therefore, the result may vary in different situations, and further research must be conducted to supplement the findings. However, if the heavy-metal contents in the waste are constant, it can be used as a reference material for the control of heavy metals in cement products.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.1
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• pp.85-91
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• 2021

Aggregate waste separator with rotating separating net was designed for applying classification process of construction waste. In order to evaluate the performance of the aggregate waste separator, according to the type of waste, standardized waste samples are prepared using acrylic. The appropriate operating point was evaluated by the classification efficiency and misclassification rate of recycled aggregate according to the control frequency of the blower operating and inlet position of the separating net. The classification efficiency at the operating point of the aggregate waste separator was evaluated through flow analysis assuming recycled aggregate and waste sample as particles. As a result of the performance test, when the distance. between the conveyor belt and the inlet was 0.2m, the classification efficiency was 95%, but the misclassification rate of recycled aggregate was 2% or more, which satisfies the classification efficiency and the misclassification rate of less than 2%. The operating point was shown at a control frequency of 58Hz at a suction distance of 0.254m. As a resu lt of flow analysis, there was no misclassification of recycled aggregate. In order to redu ce constru ction waste in the existing recycled aggregate production process, adsorption system using a rotating separating net that can be operated as an installation type was built.

• Journal of the Korea Computer Industry Society
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• v.2 no.10
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• pp.1301-1308
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• 2001

In this paper, some interesting aspects of Grzegorczyk classes $\xi\sum{n}$, n$\geq$0 & $\sum$= { 1, 2 } of word-theoretic primitive recursive functions are observed including the classes of its corresponding predicates ($\xi\sum{n}$)* In particular, the small classes $\xi\sum{n}$($n\leq2$) are very incomparable to the corresponding small classes $\xi\sum{n}$ where $\xi\sum{n}$ is the number-theoretic Grzegorczyk classes. As one of some interesting aspects of the small classes, we show that the equivalence problem in $\xi\sum{0}$is undecidable.