• Title/Summary/Keyword: deterioration of quality

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Building mix design and quality control measures to reduce the combined deterioration of plain concrete in harsh environments (혹독한 환경에서의 무근콘크리트 복합열화 저감을 위한 배합설계 및 품질관리 방안 구축)

  • Kim, Dae-Geon;Park, Chan-Kyu
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.10a
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    • pp.85-86
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    • 2016
  • Recently damages caused by the additional costs and degradation in durability combined deterioration due to plain concrete deterioration has occurred. In particular, in the case of the finish that is not exposed to the outside air in the concrete to respond to the harsh environment (freeze-thawing, calcium laying, etc.), to establish a quality control way for the process and the concrete mix design for it.

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A Study on the Track Irregularity Index for the Estimation of Track Quality (궤도품질평가를 위한 궤도틀림 지표에 대한 연구)

  • 오지택;한승용
    • Proceedings of the KSR Conference
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    • 2000.11a
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    • pp.450-457
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    • 2000
  • This paper establishes a scheme to estimate track quality using standard deviation and deterioration rate of track irregularities. To provide index of quality, standard deviation and deterioration rate of track irregularities are analyed. As an index, standard deviation and deterioration rate were applied to decision of corrective maintenance and replacement maintenance, respectively. Further, this paper proposes a basic scheme for a modernization of mechanize track maintenance that using MTT(Multiple Tie Tamper) and Ballast Cleaner.

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Influence of Cultivation Condition and Harvest Time on the Storage Stability of Fresh Ginseng Individually Packaged in a Soft Film (재배조건 및 채굴시기가 연포장재 필름으로 개별포장한 수삼의 저장성에 미치는 영향)

  • 손현주;김은희;성현순
    • Journal of Ginseng Research
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    • v.25 no.2
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    • pp.94-100
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    • 2001
  • The influence of cultivation condition and harvest time on the storage stability of the fresh ginseng (50g) individually packaged in a soft film bag (ONY/LDPE/L-LDPE; 200$\times$300 mm, 90㎛) was investigated. When the fresh ginsengs were divided into four groups of direct-planted ginseng on the paddy soil(PD), transplanted ginseng on the upland(UT) and each group was stored at 25$\^{C}$ for 40 days, the quality deterioration rate was the highest in PD group while PT, UD and UT groups exhibited similar quality patterns from each other. When each group was stored at 10$\^{C}$, the quality deterioration rate was also the highest in PD group and the other three groups exhibited similar quality patterns from each other till 90 days passed after storage. However, the quality deterioration rate of UT group was 54% which was higher than UD group or PT group 180 days after storage. When the fresh ginseng harvested between September of 1997 and October of 1998 was individually packaged with the soft film and stored at 25$\^{C}$ for 12 days, the quality deterioration rate was the lowest in the group harvested in October while relatively high in the groups harvested between July and September.

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Determination of Ratio of Wood Deterioration Using NDT Technique

  • Lee, Jun-Jae;Bae, Mun-Sung
    • Journal of the Korean Wood Science and Technology
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    • v.32 no.3
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    • pp.33-41
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    • 2004
  • In ancient wooden structures, the mechanical properties of the structural members have been reduced by time-dependent degradations such as fatigue or creep. Also, the external and internal deterioration was caused by environmental condition, fungi, bacteria, or insect, and then reduced the quality of structural members. However, the previous methods for evaluating the deterioration have been mainly depended on the visual inspection. In this study, therefore, ultrasonic stress wave test, accelerometer stress wave test were used to evaluate the deterioration of structural wood members in ancient wooden structures. Based on the results, the quantitative criteria of stress wave transmitted velocity were proposed to evaluate the deterioration of structural member. The proposed criteria were related to the degree of deterioration. In accelerometer stress wave, the criteria of deterioration of wave reciprocal velocity was below 1800 ㎲/m at incipient deterioration (below 12% ratio of deterioration), between 1800 and 2200 ㎲/m at moderate deterioration (12~17%) and above 2200 ㎲/m at severe deterioration (above 17%). The ultrasonic stress wave, the criteria of deterioration were 800 and 950 ㎲/m at below 8% and above 15% of the degree of deterioration respectively.

대용량 데이터를 처리하는 ERP시스템의 성능개선(튜닝) 사례;(주)대교

  • Seo, Byeong-Min;Kim, Seung-Il
    • 한국경영정보학회:학술대회논문집
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    • 2007.06a
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    • pp.582-587
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    • 2007
  • ERP system is a good one because it provides required data to the Board of Directors at the right time, but needs to collect many data in this system. Nevertheless, increase in data leads to the system's quality deterioration which makes companies to carry out quality improvement. In order to solve quality deterioration problem, a company's quality improvement director must execute under acknowledgement of the relationships between sectors to be improved, which are DBMS, Application, System, Data Management, Archiving, and Reorganization. But in many cases, these relationships are ignored due to massive size of each of the sectors, resulting fragmental quality improvement operation. This case paper proposes a solution to effectively solve quality deterioration problem created by the massive data produced while operating ERP System(constructed by SAP package and web). First, it defines the sectors where quality improvements are vital, and lists out things to be considered. Then, by analysing the working process of these sectors, proposes the most efficient order of the improvement process. This case will eventually help the company's quality improvement director to execute quality improvement most effectively without trials and errors, which is this paper's ultimate goal.

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The Application of Clove Extract Protects Chinese-style Sausages against Oxidation and Quality Deterioration

  • Zhang, Huiyun;Peng, Xinyan;Li, Xinling;Wu, Jingjuan;Guo, Xinyu
    • Food Science of Animal Resources
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    • v.37 no.1
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    • pp.114-122
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    • 2017
  • This study was conducted to evaluate the effects of clove extract (CE) (0.25%, 0.5%, 1%, and 2%) on the oxidative stability and quality deterioration of Chinese-style sausage stored for 21 d at $4^{\circ}C$. The addition of clove extract to sausages significantly retarded increases in Thiobarbituric Reactive Substances (TBARS) values (p<0.05), while also controlling the production of protein carbonyls (p<0.05). However, the addition of clove extract promoted reduced thiol group content in sausages (p<0.05). Sausages amended with clove extract also had decreased $L^*$ values (p<0.05) and increased $a^*$ values (p<0.05) when compared with the control. Similarly, texture deterioration was retarded in sausage containing added clove extract when compared with the control during refrigerated storage. Moreover, the addition of clove extract had no negative effects on the sensory properties of sausages. These results suggested that clove extract was effective at protecting sausages from oxidation and quality deterioration during refrigerated storage for 21 d.

Empirical Study on the Determinants of Service Quality Deterioration of Taxi Industry : Based on Traffic Accidents by Taxi in Seoul (택시서비스 품질 저하의 선행요인들에 관한 실증적 연구 : 서울지역 택시의 교통사고율을 중심으로)

  • Lee, Sang Joon;Lee, Younsuk;Shin, Hojung
    • Journal of the Korean Operations Research and Management Science Society
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    • v.40 no.4
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    • pp.83-105
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    • 2015
  • Taxi, one of the passenger services, is an essential transportation system in our society. In spite of the importance of taxi service, deterioration of the service quality is continuously reported. In particular, taxi service failures due to traffic accidents have emerged as the most serious social problem which may incur a considerable amount of social costs. In this study, we focus on analyzing the causes of service quality deterioration-traffic accidents of both corporately owned and privately owned taxies in Seoul. The research objective is to find out the determinants of service quality deterioration of Taxi industry and to suggest policies for improving the taxi service in Seoul. We collected the archival data from KTSA (Korea Transportation Safety Authority) and ODP (Open Data Portal), which span from 2005 to 2014. Hierarchical regression analyses and a set of mediation tests are conducted. The root factors inducing traffic accidents of taxies are divided into competitive, and profitability factors. The statistical results indicate that the accident ratio per taxi is not only affected by competitive/profitability factors such as number of active taxi drivers, number of bus passengers, and taxi fare, but also mediated by the traffic violation ratio. To alleviate the current problems with taxi service in Seoul, we conclude that the number of taxies be reduced and the taxi fare be increased. Finally, we suggest several policies to improve the endemic taxi industry problems, over-supply and the low profitability by enhancing the linkage between service quality and profitability.

Water Quality Modeling of the Eutrophic Transition Zone in a River-Type Reservoir Paldang (부영양화된 하천형 호소(팔당호) 전이대의 수질모델링)

  • Kong, Dongsoo
    • Journal of Korean Society on Water Environment
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    • v.30 no.4
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    • pp.429-440
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    • 2014
  • This study was conducted to investigate the main cause of water quality deterioration during the spring season in the transition zone between the South Han River and the river-reservoir Paldang. A water quality model modified from QUAL2E (U.S.EPA) was used, and the model showed that eutrophication and algal production in the low flow season affected about 60% of the organic pollution at the downstream of the South Han River. This result means that phosphorus control is prior to external organic material management to ameliorate the deterioration of water quality in the water body.

The Study on Texture-Softening of Tentatively Thermal Processed Orange Sac (Orange Sac 1차 가공품의 조직연화에 관한 연구)

  • 장재권
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.4
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    • pp.653-658
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    • 1998
  • In order to provide orange sac for off-season processing of sac-suspended orange juice, orange was treatee into intermediate production of orange sac and segment, stored at 2$0^{\circ}C$ during 3 months for assessment of sac-quality providing various processing conditions. Lowering the pH of syrup and sterilization temperature reduced the deterioration of sac quality in terms of intensity and destruction of sac. Sugar content of syrup had little relation with intensity of orange sac at pH 6.5, whereas in the range of pH 3.0~3.8, the increase of sugar content increased intensity of sac. The storage of segment form maintained better quality than that of sac form. The absorbance of syrup was linearly inverse to sac intensity. The deterioration of sac quality may be related to effulence of some materails in sac. Sac product sterilized at below $65^{\circ}C$ had possibility to be contaminated by microbes.

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A method of selecting an active factor and its robustness against correlation in the data

  • Yamada, Shu;Harashima, Jun
    • International Journal of Quality Innovation
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    • v.4 no.2
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    • pp.16-31
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    • 2003
  • A reducing variation of quality characteristics is a typical example of quality improvement. In such a case, we treat the quality characteristic, as a response variable and need to find active factors affecting the response from many candidate factors since reducing the variation of the response will be achieved by reducing variation of the active factors. In this paper, we first derive a method of selecting an active factor by linear regression. It is well known that correlation between factors deteriorates the precision of estimators. We, therefore, examine robustness of the selecting method against the correlation in the data set and derive an evaluation method of the deterioration brought by the correlation. Furthermore, some examples of selecting and evaluation methods are shown to demonstrate practical usage of the methods.