• The Korean Journal of Applied Statistics
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• v.29 no.7
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• pp.1421-1428
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• 2016

This paper concerns the freshness of rice depending on packing materials using MANOVA. Freshness of rice is measured in terms of moisture content and rice flavor. Ordinary paper and charcoal-coated paper are compared as packing materials. Storing places are considered as a block. The bivariate observations of moisture content and the rice flavor are compared using MANOVA for a completely randomized block design. It is observed that there is a significant difference between ordinary paper and charcoal-coated paper. Therefore we apply ANOVA for moisture content and rice flavor, respectively. Significant differences are observed for the moisture content but not for the rice flavor.

• 한국도로학회지:도로
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• v.10 no.4
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• pp.68-73
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• 2008

• International Journal of Highway Engineering
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• v.13 no.1
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• pp.223-228
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• 2011

The initial joint width design of the terminal joint between post-tensioned concrete pavement (PTCP) and jointed concrete pavement (JCP) was studied in this research. The joint width between PTCP and JCP directly affects noise and ride quality. If the initial joint width is very large, noise increases and ride quality decreases. If the initial joint width is very small, on the other hand, under high temperatures, PTCP slabs can blow up, or failures near the joint can occur due to excessive compressive stresses. The terminal joint width behavior between PTCP and JCP near Jumunjin at Donghae expressway under temperature changes was measured in August and November 2010 and the data was analyzed. From this study, the design methodology of the optimal initial terminal joint width was proposed.

• Journal of Korean Society of Steel Construction
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• v.13 no.2
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• pp.211-221
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• 2001

The dynamic force estimation and strength design of KALES(Korea Accelerated Loading and Environmental Simulator) are studied. The KALES is continuously rotating the test track and subjected to the dynamic or impact forces during operation since the track is composed of straight and curved line. To estimate the dynamic equation for the model car which was already made is derived with analytical and experimental techniques. Using similarity relationships between the model car and KALES, the dynamic force and stability properties for KALES can be predicted. The stress analysis and fatigue life estimation of KALES is also estimated with the calculated dynamic load. From the stress analysis and fatigue life estimation results, it was found that the design of KALES is safe.

• International Journal of Highway Engineering
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• v.11 no.2
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• pp.1-15
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• 2009

Surface of exposed aggregate concrete pavements is consists of exposed coarse aggregate by removing upper 2$\sim$3mm mortar of concrete slab. Exposed aggregate concrete pavements have advantages of maintaining low-noise and adequate skid-resistance level during the performance period. In order to provide the successful exposed concrete aggregate pavement, uniform distribution of the coarse aggregate on pavement surface through adequate the mix design and exposing method. The mix design in concrete pavement is generally designed on the basis of strength, but mix design of exposed aggregate pavement employed in this study includes the consideration of noise and skid resistance, as well as strength. Smaller of maximum coarse aggregate is known to be effective for reduce noise level. Optimum mix design and exposing method of fine-size exposed aggregate portland cement concrete pavement that can reducing the noise and maintain the adequate level of skid resistance are proposed in this study. To consider the variation of optimum exposing time due to the hardening speed of mortar by climatic condition, quantitative is also suggested measurement of hardening state.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.3
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• pp.51-58
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• 2008

Development of a new design guide which is based on empirical-mechanistic concept for pavement design is in action. It is called AASHTO 2002 Design Guide in USA and the KPRP(Korean Pavement Research Project) in Korea. The material characteristic of hot mix asphalt is a key role in the design guide. Therefore it is urgent to get a proper materials database, especially the dynamic modulus of hot mix asphalt. In this research, dynamic modulus test, which is based on aged asphalt binder, has been carried out and proposed the predicted equation of dynamic modulus. Nine different hot mix asphalt with three different asphalt binder have been used for the dynamic modulus test. Short-term aging, which is covers the time for the production of asphalt plant, transportation, lay-down, and compaction, can be simulated at $135^{\circ}C$ with 2 hour curing. Long-term aging has been carried out for a performance period of asphalt pavement. The dynamic modulus of asphalt pavement increases with aging time. As the nominal aggregate size increases, the change of dynamic modulus is not big.

• Corrugated packaging logistics
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• s.63
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• pp.87-90
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• 2005

1856년 7월 7일 영국에서 에드워드 찰스 힐리와 에드워드 엘리스 알렌 (Edward Charles Healey & Edward Ellis Allen)에 의해 골판지가 처음 발명되었고, 15년후인 1871년 12월 19일에 현재의 골판지상자 형태의 특허가 미국의 알버트 L. 존스(Albert. L. Jones)에게 취득 된지 130여년이상이 지난 이 시대에는 실로 다양한 분야에서 골판지를 사용하고 있지만, 주 사용분야는 포장산업의 분야이다. 과거에는 포장의 주목적은 첫째 포장 내용물(상품)의 보호 둘째 상품의 운송과 적재 및 취급의 편리성 셋째 상품 구매동기 유발의 순서이었으나 최근에는 첫째와 둘째의 목적은 필수불가결한 것이고 세번째의 상품 구매동기 유발의 목적에 더 큰 비중이 있는 추세이다. 따라서 포장재의 규격은 생산자의 입장에서는 보다 단순해지고 규격화 되는 것이 생산코스트의 절감과 생산성 향상의 지름길이지만 (그러나 더욱 복잡해지고 비규격화 되는 것이 제품 부가가치가 더 높을 수도 있기 때문에 여기에는 보다 신중한 판단이 필요하다)각종 통신기술, 인터넷과 I.T산업의 발달과 더불어 소비자가 언제라도 상품의 다양한 정보에 쉽게 접할 수 있는 이시대에는, 다양한 소비계층의 NEED를모두 만족시켜 줄려고 하는 상품 개발자의 제품설계 및 개발과 판매전략에 의해 더욱 더 상품은 다양해지고 이에 따라서 포장재의 형태도 더욱 다양해지고 복잡해지고 있다. (필자의 판단으로는 앞으로 보다 더 다양해지고 복잡해지고 있는 추세이다.) 즉 다시 말하면 이러한 다양한 형태의 포장재의 변화를 수용하여, 가장 높은 가격 경쟁력으로, 적시에 가장 빠르게 생산하며 공급할 수 있는 능력을 갖춘 포장재 제조업자 만이 미래에는 적자생존 할 수 있다는 결론이다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.2
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• pp.67-76
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• 1992

A procedure to determine the axle load limits of asphalt concrete pavements are proposed in this study. Axle load limits are determined by calculating maximum tensile strains at the bottom of the asphalt stabilized base layer and maximum vertical strains at the top of the subgrade. In order to investigate the efficiency of axle configuration, calculated influence line of wheel load on domestic expressway pavement system is used. Limiting strains are selected through the analysis of conventional failure criteria. From the analysis of axle load limits about axle composition(single-axle, tandem-axle, tridem-axle), it is found that the axle load limits of tandem-axle and tridem-axle can be calculated by muitipling the axle load limits of single-axle by axle numbers and that axle load limits are closely related to the thickness of each layer of pavement structure. It is also found that the axle load limits by tensile strains are more critical than those by vertical strains on asphalt concrete pavement models of YOUNG-DONG, KYONG-IN and KYONG-BU expressways.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1D
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• pp.81-87
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• 2006

The rubblization technique is breaking the aged concrete pavement slab into rubblized concrete aggregate, and use it as an base material at its original position, then builds overlay above the rubblized base. This method has been successively used in USA due to the advantage of good constructibility, cost-effectiveness as well as the capability of preventing of reflection cracks. However, constructibility and economic performance of rubblization on typical Korean concrete pavements needed to be investigate since to typical Korean concrete pavements have thick slab, as well include lean concrete subbase course. Multi-head type breaker suitable for Korean condition was designed and developed. This multi-head type breaker was designed to rubblize old concrete to the suggested optimum rubblized-depth and rubblized-concrete-aggregate size to prevent reflection crack and maintain high bearing capacity. This machine was used for the test of rubblization of old concrete pavement on a non-use old concrete and a in-serviced road. In these two tests, engineering properties of rubblized base and constructability and cost were investigated. In both tests, the old concrete rubblized to targeted size and depth, and high-level bearing capacity was achieved. Also, superior constructability and lower cost compared with traditional reconstruction was examined.

• Journal of the Korean Geotechnical Society
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• v.28 no.3
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• pp.5-14
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• 2012

In the current design codes for anti-freezing layer, the thickness of anti-freezing layer is calculated by freezing depth against the temperature condition. Therefore, they have a tendency of over-design and uniform thickness without the considerations of thermal stability, bearing capacity and frost susceptibility of materials. So, it is essential for studying the appropriateness and bearing capacity of road foundation materials as well as their seasonal and mechanical properties to take an appropriate and reasonable design of the road structure system. In this paper, the freezing and bearing capacity characteristics of typical road foundation materials were evaluated in the large scale laboratory test. LFWD (light falling weight deflectometer) was used to determine the change of elastic modulus ($E_{LFWD}$) caused by to the frost heave and thaw. Furthermore, the influence of crushed natural aggregate on the freezing of the subgrade soil was studied to verify the function and effectiveness of the anti-freezing layer.