• Computers and Concrete
• /
• 제19권1호
• /
• pp.111-120
• /
• 2017

This study aimed to design the accelerated life testing (ALT) of concrete, which stimulating the special natural environment maximumly. Its evaluation indexes, such as dynamic elastic modulus, mass and ultrasonic velocity were measured, and the variation of relative mass and relative dynamic elastic modulus of concrete were studied. Meanwhile, the microanalysis method was used. Moreover, an exploratory application of the stochastic approach, the Weibull distribution and the lognormal distribution, were made to assess the durability of concrete structures. The results show that the ALT for simulating natural environment is more close to the service process of concrete structure under actual conditions; The relative dynamic elastic modulus can be used as the dominant durability evaluation parameters, because it is more sensitive to the environmental factors compared with the relative quality evaluation parameters; In the course of the concrete deterioration, the destruction of the salt freezing cycle is the dominant factor, supplemented by other factors; Both of those two stochastic approaches can be used to evaluate the reliability of concrete specimens under the condition of ALT; By comparison, The lognormal distribution method is better to describe the reliability process.

• Advances in concrete construction
• /
• 제6권1호
• /
• pp.47-68
• /
• 2018

This article reports the utilization of fly ash (FA) waste product from industry and silpozz which is an agro-waste from agriculture as an environmental friendly material in construction industry. The evaluation of strength and durability study was observed using FA and silpozz as a partial replacement of Ordinary Portland Cement (OPC). The studied parameters are compressive strength, flexural strength, split tensile strength and bond strength as well as the durability study involves the acid soluble chloride (ASC), water soluble chloride (WSC), water absorption and sorptivity. Scanning electron microscopy (SEM) and XRD of selected samples are also done. It reveals from the test results that the deterioration factor (DF) in compressive strength is 4% at 365 days. The DF of split tensile strength and flexural strength is 0.96% and 0.6% at 90 days respectively. The minimum slip is 1mm and 1.1mm after 28 days of testing bond strength for NWC and SWC sample respectively. The percentage decrease in bond strength is 10.35% for 28 days SWC samples. The pre-cast blended concrete samples performed better to chloride diffusion. Modulus of elasticity of SWC samples are also studied.The water absorption and sorptivity tests are conducted after 28 days of curing.

• Computers and Concrete
• /
• 제20권1호
• /
• pp.99-110
• /
• 2017

Service life assessments which do not include the synergy between mechanical and environmental loading are neglecting a factor that can have a significant impact on structural safety and durability assessment. The degradation of concrete structure is a result of the combined effect of environmental and mechanical factors. In order to make service life design realistic it is necessary to consider both of these factors acting simultaneously. This paper deals with the advanced modelling of concrete carbonation and chloride ingress into concrete using stochastic 1D and 2D models. Widely accepted models incorporated into the new fib Model Code 2010 are extended to include factors that reflect the coupled effects of mechanical and environmental loads on the durability and reliability of reinforced concrete structures. An example of cooling tower degradation by carbonation and an example of a bended reinforced concrete beam kept for several years in salt fog are numerically studied to show the capability of the stochastic approach. The modelled degradation measures are compared with experimental results, leading to good agreement.

• 한국의상디자인학회지
• /
• 제17권2호
• /
• pp.239-249
• /
• 2015

This study was focused on how the various materials of footwear affect the preferences of functionality and the level of discomfort when wearing. Datas were collected using questionnaire, age of 20's to 50's of female and male. Results were analysed using SPSS WIN 2.0 through t-test and ANOVA test. Results are as follows: In the preferences of materials of footwear, datas showed the shoes are of genuine leather, the sneakers are of textiles, the sandals are of man-made leather and the boots are of genuine leather. The important factor to the preferences of the materials were the leathers in the durability, the man-made leathers in easy-care and maintenance, the rubber and the complex materials in comforts. The level of the discomforts of the footwear were highly ranked in genuine leather, the man-made leather and the complex material with man-made leather and textiles followed. Man-made leather and the textiles represented the discomfort in the ankle. Mostly discomforts of the footwear showed in the sole and the top side of the foot in all kinds of footwear. The preferences in functionality were collected by the female, also female preferred the comfort the first, male preferred the durability. And the texture and the durability were highly preferred in aged female and male.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
• /
• pp.187-187
• /
• 2011

Nowadays, the issue of solar cell durability in local weather and environment is a crucial issue. Above all, surface corrosion on solar cell multilayers is a major factor that determines the durability of commercial solar cells; corrosive chemical interactions between air, humidity and chemical species and solar cell multilayers can unfavorably affect the durability. Here, we study microscopic and spectroscopic surface techniques to investigate the corrosive interaction on the antireflective layers of solar cell multilayers under various conditions such as acid, base, constant temperature and humidity. Surface morphology and adhesion force were characterized with atomic force microscopy before and after chemical treatment. Chemical composition, and transmittance factors were studied with X-ray photoelectron spectroscopy, and ultraviolet-visible spectroscopy, respectively. Based on these studies, we suggest the dominant factors in the corrosive chemical processes, and their influences on the structural, compositional, and optical properties of the antireflective layers.

• 한국의류산업학회지
• /
• 제11권1호
• /
• pp.33-40
• /
• 2009

The purpose of this study was to examine the relationship of masstige clothing benefit seeking and brand loyalty. The data were collected from university students, 248 males and 262 females, living in Gyeong-ju, via a self-administered questionnaire. The data were analyzed by reliability analysis, factor analysis, Pearson's correlation, regression analysis, and t-test. The results of this study were as follows: 1) Four factors of the masstige clothing benefit seeking were identified; the rise of the social position and self-improvement, the popularity and durability, the desire for individuality and favorable impression, and the rare and precious value. Three factors of the brand loyalty were identified; the committed brand loyalty, the continued brand loyalty, and the symbolic brand loyalty. 2) The committed brand loyalty had a positive relation with two factors of masstige clothing benefit seeking, that is, the popularity and durability, the desire for individuality and favorable impression. The symbolic brand loyalty had a positive relation with the rise of the social position and self-improvement of masstige clothing benefit seeking. 3) There was sex difference on the desire for individuality and favorable impression, the popularity and durability of the masstige clothing benefit seeking. Also, there was sex difference on the committed brand loyalty.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2006년도 추계학술대회 논문집
• /
• pp.1385-1390
• /
• 2006

Concrete structure can be deteriorated by ingress of moisture and aggressive agents. To maintain the sound performance of concrete structure during the service life, it needs to protect concrete from ingress of moisture and aggressive agents before arising deterioration of concrete. Protection of concrete is possible by surface treatment. In this study, durability of the functional nano composite inorganic activated carbon based coatings which can provide a barrier against the ingress of moisture or aggressive ions to concrete is discussed. For the durability evaluation of the coatings, fine void structure evaluation test, chloride penetration acceleration test, accelerated carbonation test, freezing and thawing test, and the accelerated test of chemical erosion are conducted. As the result of this study, the functional nano composite inorganic activated carbon based coatings which became one formed complex compound with adsorption and porosity on concrete surface, had an effect on the function of far infrared radiation, antimicrobial action, air cleaning, airing assurance, and the interception of moisture of deterioration factor, chloride ion, carbon dioxide, sulfate, and so on.

• 한국자동차공학회논문집
• /
• 제10권5호
• /
• pp.9-14
• /
• 2002

The durability prediction of emission control components, especially 02 sensor and catalytic converter, is getting more important as emission regulation is getting stricter and vehicle durability mileage requirement is also extended from 80,000 ㎞ to 160,000 km in Korean market. And the duration of vehicle mileage accumulation to get vehicle exhaust emission deterioration factor for certification is required to be shorter in order to reduce the vehicle development time. Since most of the vehicle emission development tests are done on chassis dynamometer and aging bench by using vehicle aging modes, real road condition and in-use driving patterns must be reflected into them to predict the vehicle emission level and to meet emission regulation especially at high mileage. In order to get the frequent driving pattern of vehicle and the aging characteristic of emission components, a vehicle was tested by changing drivers and driving roads around Seoul. Real road driving patterns were analyzed and compared with those of the certification modes which are well known in automotive industry.

• 패션비즈니스
• /
• 제6권4호
• /
• pp.141-150
• /
• 2002

The purpose of this study was to investigate factors to influence on buying behavior of Chinese male consumers in regards to apparel types. Furthermore, this study provided fundamental data for marketing strategy in export apparel business to China from domestic apparel business. Returned 863 questionnaires from Chinese male consumers analyzed by factor analysis, and multidimensional scaling with SPSS10.0. The result of this study were as follows: Chinese male consumers bought formal wear with evaluating two groups of factors; one for functional (fitness, A/S, durability, and management), the other for external (brand, and trend). They bought casual wear with evaluating three groups of factors; functional/useful (price, A/S, and durability), aesthetic (color, and design), and external (brand and trend). Also they bought sports wear with evaluating three groups of factors; functional/useful(price, A/S, durability, and fabric), aesthetic(design and color), and external(brand and coordination).

• 드라이브 ㆍ 컨트롤
• /
• 제19권4호
• /
• pp.29-35
• /
• 2022

In this paper, we developed a workload index for monitoring the durability test using operation information of an excavator. First, the acceleration and cylinder pressure were selected as load factors by analyzing operation data. Through load correlation analysis according to each load factor, Root Mean Square (RMS) and Work Load Range (WLR) were respectively derived as a load feature representing mechanical load. In addition, the workload index was used to quantify load features. For applying the workload index to monitoring, a real-time monitoring system consisting of sensors and embedded controller was installed on the excavator and the system was integrated with a remote monitoring environment using a wireless network. Results of load monitoring and analysis verified that the developed workload index was effective from the viewpoint of the relative comparison of the workload.