• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.1
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• pp.157-164
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• 2006

This paper presents the durability characteristics of commercially available CFRP rebars under various environmental conditions. Two types of GFRP rebars were tested by using an accelerated aging method. A total of 264 rebar specimens were conditioned up to 132 days in the moisture, chloride. alkaline, and freeze-thaw environmental conditions. The durability characteristics of conditioned rebars were obtained by comparing the tensile strength, horizontal shear strength, and elastic modulus between the unconditioned and conditioned GFRP rebars. The test results indicated that the mechanical properties of GFRP were significantly reduced after conditioning. Long-term degradation of GFRP rebars was also estimated using the results of a short-term durability test.

• Journal of Korean Society of Steel Construction
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• v.19 no.1
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• pp.79-86
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• 2007

The corrosion durability of steel bridge coatings, such as organic and metallic coatings, is often evaluated by field exposure tests, but such tests take from several years to decades to complete. As a potential method for fast corrosion testing, accelerated exposure tests were considered in this study. The S6-cycle accelerated exposure test, specified in the Japanese Industrial Standards (JIS K5621), was carried out on uncoated structural steels for 30, 60, 90, 120 and 150 days, and the resultant weight loss was determined. The weight loss was compared with that obtained from previous field exposure tests, and acceleration factors of the S6-cycle test to field exposure test sites were determined. The application of the S6-cycle accelerated exposure tests to field environments was presented based on the acceleration factor and the amount of flying salt.

• Journal of Korean Society of Steel Construction
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• v.20 no.2
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• pp.313-321
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• 2008

Recently in Japan, fracturing was observed on the diagonal member of a through truss bridge at the boundary region with the concrete slab. Local corrosion damage where the diagonal member was enclosed in the concrete slab is an important factor in the fracture. In this study, accelerated exposure tests were carried out on concrete-steel model specimens simulating steel members at the boundary with concrete. Fatigue tests were then performed on the corroded model specimens. Accelerated exposure tests of the S6-cycle, which is carried out on the model specimens for 150, 300, 450 and 600 da ys. Their surface geometry was then measured. From the accelerated exposure test results, change in maximum and mean corrosion depths was determined according to the testing periods. The effect of local corrosion on fatigue strength was also presented based on the fatigue test results.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.10a
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• pp.83-84
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• 2014

This study evaluated the effectiveness of biostimulating agent in contaminated coastal sediment. The study was conducted via column tests in coastal sea wherein two separate columns were employed for two different polymers used and another column for a blank. The biostimulating agent was made by mixing sea sediment with biostimulants viz acetate, nitrate, sulfate. The biostimulating agent was then rolled into balls, dried and coated with either Cellulose Acetate (CA) or Polysulfone (PS) to control the release of the biostimulants. The pH was around 7.6~8 for 4 months while COD, TP and TN were significantly lower in the column containing biostimulating agents. Heavy metal(Fe, Zn, Cd, Cr, Pb, Cu) was converted to stable forms and PS coated biostimulating agent had a high efficiency of heavy metals distribution.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.691-694
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• 2009

TBAB (Tetra-n-butyl ammonium bromide)는 상압에서 semi-clathrate를 형성하는 물질로서 최근 열역학적 촉진제 및 기체 저장 물질로서 주목받고 있다. 본 연구에서는 가스 하이드레이트 형성 시TBAB가 열역학적 촉진제로서 미치는 영향을 알아보기 위해 다양한 농도 (5, 10, 40, 60 wt%)의 TBAB를 $CH_4\;+\;H_2O$계, $CO_2\;+\;H_2O$계, $N_2\;+\;H_2O$계에 첨가하여 가스 하이드레이트 3상 평형 (H - LW - V)을 측정 하였다. 실험 결과 TBAB의 조성에 따른 촉진경향은 각 계가 유사하지만, 촉진 정도는 $N_2\;+\;H_2O$ 계가 앞의 두계에 비해 월등히 큰 것을 알 수 있었다. 또한, TBAB 농도가 40 wt% 일때 촉진효과가 가장 크게 나타났으며, 그 이상의 농도에서는 반대로 촉진효과가 감소하는 것을 알 수 있었다. 이는 혼합 하이드레이트 형성에 참여하지 못한 TBAB가 가스 하이드레이트 형성을 억제하기 때문으로 사료된다. 결과적으로 가스하이드레이트 공정에 TBAB를 열역학적 촉진제로서 적용할 경우 촉진효과가 가장 큰 40 wt% 범위의 농도로 사용하는 것이 가장 적절할 것으로 사료된다. 본 실험에서 얻어진 결과는 가스 하이드레이트 형성을 이용한 천연가스 수송/저장법을 위한 연구뿐만 아니라 기체 분리 공정 개발과 관련된 연구의 중요한 기초 자료가 될 것이다.

• The Korean Journal of Rheology
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• v.6 no.1
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• pp.66-74
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• 1994

천연고무의 소련효과를 높이기 위하여 사용되는 소련촉진제가 천연고무 배합물의 점도나 Couette 보정치와 같은 유변학적 특성에 미치는 효과를 살펴보았다. 소련촉진제로는 BAPS, PCTP 및 ADS계의 것이 사용되었다. 실험결과 소련 촉진제의 사용에 따라 고무의 분자량이 감소하고 전단 점도도 감소하였다. Coutte 보정치는 소련촉전제의 사용량이 증가 할수록 낮은 값을 나타냈으며 압출물의 팽창도 소련촉진제를 사용하는 경우감소하였다. 그 러나 사용된 소련촉진제들 간에는 큰 차이를 보이지 않았다.

• Annual Conference on Human and Language Technology
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• 1997.10a
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• pp.505-512
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• 1997

문자로 표기된 단어의 의미를 파악 과정에 음운 정보가 개입하는지를 결정하기 위해 3 개의 실험을 실시하였다. 예컨대, [동닙 신문]과 [목립 신문]을 제시하고 이들이 구(句)가 성립되는지를 판단케 한 실험 1에서는 [동닙 신문]을 "독립 신문"으로 오판한 확률이 [목립 신문]을 "독립 신문"으로 오판한 확률보다 낮았다. [국립]과 [공립] 그리고 [궁닙]과 [공립]을 각각 차례로 제시하고, 두 번째 제시된 단어("공립")를 명명하는 데 소요된 시간을 측정한 실험 2에서는, 앞서 제시된 [궁닙]이 뒤에 제시되는 [공립]의 명명을 다소 용이하게 하였지만 그 정도는 미미하였으며, 앞서 제시된 [국립]이 [공립]의 명명을 촉진시킨 것에 크게 못 미쳤다. 실험 2에서와 동일한 자극 재료에다, 명명과제 대신 어휘판단 과제를 이용한 실험 3에서는 "국립"과 동음인 비단어 [궁닙]이 [정립]보다는 [공립]의 인식을 촉진시켰지만, [국립]이 [공립]인식을 촉진시진 정도에는 크게 못미쳤다. 이들 결과를 종합하면, 음운 정보는 의미 파악에 부수적인 도움 정도만 제공한다는 결론이 도출된다.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.645-650
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• 1998

작물과 채소류의 생육에 대한 저선량 방사선 조사효과를 보고자 온실과 포장실험을 수행한 결과, 발아율과 유묘초장을 조사한 초기생육의 경우 벼, 콩 및 들깨의 200rad, 400rad, 100rad에서 생육촉진 효과를 볼 수 있었다 포장실험에서 벼의 경우 저선량조사에 의해 수량증가 효과는 없었고 종자의 불임율이 감소하였으며 콩과 들깨의 경우 400rad에서 생육상태와 수량이 다소 양호하여 저선량에 의한 생육촉진 효과가 인정되었다. 배추와 무의 경우는 200rad에서 발아율이 증가하여 저선량조사에 의한 효과를 볼 수 있었고 800rad에서 초장 등이 다소 증가하였으나 뚜렷한 수량증가 효과는 볼 수 없었다.

• Journal of Distribution Research
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• v.16 no.1
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• pp.117-140
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• 2011

The sales promotion strategy can be classified into two categories: cost-down and value-added promotions. Although many studies have been performed on sales promotion in the past, little attention has been given on cost-down promotion, and in particular on its strategy. Also there has been a renewed interest on value-added promotion strategy as means of attracting more customers and delivering value by providing a greater benefit. This study examines the effect of value-added promotion on the evaluation of promotional products. The topic is important because the value-added promotions are not always perceived as a benefit by consumers and they depend on the situational factors. We postulate three hypotheses on the basis of related literature. We conduct two studies: one employing experiment (study 1) and the other, quasi-experiment (study 2) to investigate the effect of two situational factors, namely the promotional package type and retailer uncertainty on the valuation of promotional products. Study 1 employs 2 promotional package types (bundled with freebie type vs. one-plus-one type) by 3 evaluation targets (overall package, a focal product and freebie) in experimental design. Also it is found that consumers devaluate the promotional product when the level of retailer uncertainty is high (t=-4.70, p=.000) as shown in Table 2. As depicted in Figure 2, the interaction effect of retailer uncertainty and package types on the evaluation of promotional product as a whole does not appear to be significant. However, when the level of retailer uncertainty is high, the focal product suffers from lower valuation if it is included in a bundle with freebie type package. The purpose of Study 2 is to cross-check the results of Study 1. The results of Study 2 also show that the consumers devaluate the promotional products as a whole when the level of retailer uncertainty is high. Furthermore, Study2 examines the consumers' willingness to purchase. The willingness to purchase of 2 different consumer groups divided by their reservation prices before and after exposure to a promotional stimuli shows no significant differences(t=1.911, p=.057). The results suggest that the consumers' reservation prices before the exposure to the promotion can be a reference prices of their's. But after the promotional events, the promotional price would become their reference prices. Furthermore, when the level of retailer uncertainty is high, consumers devaluate the promotional product as a whole. Because the promotional offerings activate the persuasion knowledge of consumers and make them incorporate negative inference about the firm's motives into their valuation and consequently, consumers tend to hesitate to purchase.

• The Korean Journal of Mycology
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• v.15 no.4
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• pp.238-246
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• 1987

Aspergillus niger van Tieghem was cultured by the method of synchronous and submerged culture. The sporulation occurred through the culture and its life cycle and differentiation were completed in the experiments. The effects of cAMP, theophylline and caffeine on the sporulation of A. niger were investigated. In the sporulation medium, the sporulation was stimulated by addition of cAMP and its optimum concentration was $10^{-4}M$. In the sporulation medium, the sporulation was stimulated by addition of theophylline and its optimum concentration was 10 mg/ml. In the sporulation medium, the sporulation was stimulated by addition of caffeine and its optimum concentration was 300 mg/ml. Theophylline added to the sporulation medium together with cAMP enhanced the promotion effect of cAMP on sporulation. Caffeine added to the sporulation medium together with cAMP enhanced the promotion effect of cAMP on sporulation. In the sporulation medium, the sporulation was stimulated by addition of neither AMP nor ATP. In the potassium acetate medium, cAMP, theophylline and caffeine stimulated the sporulation, respectively.