• Title/Summary/Keyword: Long-term stability

Search Result 1,157, Processing Time 0.027 seconds

How do Merchandisers in Large Retailers Purchase Agriculture Products? (대형유통업체 구매담당자의 농산물 구매 행태에 관한 연구)

  • Woo, Young-Mun
    • Journal of Distribution Research
    • /
    • v.16 no.5
    • /
    • pp.123-140
    • /
    • 2011
  • This study analyzed large distributors' trade features with local suppliers and their direct purchase features through the survey and the interview targeting some MDs(Merchandisers) in large retailers responsible for buying fresh foods (agricultural, fishery, livestock and proceeded products). As the result of conducting the survey targeting the large purchase MDs, it was found that when they select local suppliers, they importantly consider the factors of stable products supply, the quality management, the aggressive management attitude, the affordable (cheap) price, and the suggestion of differentiated goods in order. Concerning their direct purchases in local places, their preference toward the direct-purchase traders were higher than that toward vendors and whole markets as their existing major traders. Among the traders for direct purchase, they preferred farm corporations (including agricultural corporations) the most, and followed the National Agricultural Cooperative, and the unit agricultural cooperative in order. Regarding to the trades with suppliers, when they set the trade price, the merchandisers (MDs) of large distributors preferred long-term trades over 2 years, and utilized the factors of market rate(50.9%), production cost(31.2%) and sale price in the same industry(18.0%). For the local distribution organizations to aggressively counteract the changes of distribution environment in the consumption places, it needs some strategies to organize the agricultural production, to expand the production size and to specialize the distribution channels. And the supply system's continuality and stability are required, so it needs to establish the counteract system enabling to supply all year round through the link of production organizations. Additionally, as an effort to intensify the market negotiation ability, it should collect various market information from the consumption places.

  • PDF

A Study on the Result of Application of Designation Criteria for Urban Regeneration Activation Zone by the Spatial Range (공간적 범위의 차이에 의한 도시재생 활성화지역 지정기준 적용 결과에 관한 연구)

  • Lee, Jong Hwi;Lee, Tae Hee
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.21 no.10
    • /
    • pp.567-573
    • /
    • 2020
  • This study was done to develop indicators for cities that can be used in the long term and in a sustainable manner. Activation indicators were developed to improve the resilience in the downtown area of Seo-gu, Incheon. Preliminary indicators were derived from prior studies on similar indicators of resilience for urban regeneration, and an expert opinion survey was conducted to analyze the suitability and importance of the indicators. Activation indicators were established for improving urban resilience in six areas: population stability, social inclusion, industrial diversity, local productivity, environmental sustainability, and social-based convenience. From 60 preliminary indicators, 42 indicators were selected through the expert opinion surveys for securing an economically active population, establishing a living infrastructure, improving the settlement environment, and upgrading industry to reflect the characteristics of the West, including industrial complexes. It was found that diversification is necessary. Further study is still necessary to improve the objectivity of the indicators and calculate a resilience index. The significance of this study is that it looks at quantitative indicators, complements other studies on regional decline diagnosis, and presents realistic alternatives suitable for domestic situations based on the concept of resilience.

An Evaluation of N.Korean SEZs through Comparing with China's and Vietnam's Initial Cases (중국과 베트남 초기 경제특구와 비교를 통한 북한 경제특구 평가)

  • Kim, Mi-Suk;Choi, Dae-Sik;Kim, Doo-Whan
    • Land and Housing Review
    • /
    • v.7 no.4
    • /
    • pp.191-205
    • /
    • 2016
  • North Korea(NK) has designated the special economic zones(SEZs) since the first one in Rason. But, why have the SEZs in NK still not been developed successfully? This study comparatively evaluated the SEZs in China, Vietnam and NK, with respect to 'context/purpose', 'development/management system', and 'location/infrastructure.' NK's strategies for the SEZs were different from those of China and Vietnam in terms of historical context and development purpose. China and Vietnam chose the market opening policy aiming to reform their national economy, while NK tried the opening policy without the economic reform. This difference made NK's decentralization and location strategies marginal. In spite of the positive land system and tax benefit of NK, the strategies couldn't make a successful result. The implications of this comparative study are as follows. Firstly, NK needs to establish a strategy for the SEZs in accord with the comprehensive and long-term plan for economic development and 'trustworthy and substantial market-systems' being compatible with outside world. For that, NK has to secure the regime stability in political and diplomatic dimensions. Secondly, NK has to carry out policies of decentralization and location of the SEZs more positively. Thirdly, in order to solve the problem related to lack of infrastructure capital, NK needs to utilize a BOT scheme.

Synthesis of C9-Alcohol through C9-Aldehyde Hydrogenation over Copper Catalysts (구리 촉매 상에서 C9-알데히드의 수소화 반응에 의한 C9-알코올 합성)

  • Park, Young-Kwon;Noh, Sang Gyun;Cho, Kyu Sang;Jeon, Jong-Ki
    • Korean Chemical Engineering Research
    • /
    • v.44 no.4
    • /
    • pp.363-368
    • /
    • 2006
  • This study selected the optimal catalyst for the process of producing $C_9$-alcohol by hydrogenating $C_9$-aldehyde, and carried out an experiment in order to establish the operating condition for maximizing the yield of $C_9$-alcohol. The BET surface area and the specific area of copper were most excellent in $CuO/ZnO/Al_2O_3$ (60:30:10 wt%) catalyst produced using acetate as a precursor of copper and $Na_2CO_3$ as a precipitant, and the catalyst also showed the highest performance in $C_9$-aldehyde hydrogenation. Using a trickle bed reactor loaded with optimized catalyst, we attained 94.1 wt% yield of $C_9$-alcohol under the condition of $175^{\circ}C$, 800 psi and $WHSV=3hr^{-1}$. According to the result of comparing with other catalysts used in the hydrogenation of aldehyde, the catalyst showed similar performance to that of Ni/kieselghur and higher than that of $Cu-Ni-Cr-Na/Al_2O_3$ and $Ni-Mo/Al_2O_3$. According to the result of examining the stability of the catalyst through a long-term catalysis test, the yield of $C_9$-alcohol decreased slowly after around 72 hours due to the increasing production of high boiling-point byproducts.

The Fundamental Study on th e Soil Remediation for Copper Contaminated Soil using Nanobubble Water (나노버블수에 의한 구리 오염 토양의 정화에 관한 기초 연구)

  • Jeong, So-Hee;Kim, Dong-Chan;Han, Jung-Geun
    • Journal of the Korean Geosynthetics Society
    • /
    • v.16 no.1
    • /
    • pp.31-39
    • /
    • 2017
  • The fundamental study for an application of nanobubble as a soil remediation enhancer on heavy metal contaminated soil was carried out. The existence and long-term stability of hydrogen nanobubbles were investigated by particle analysis and zeta-potential analysis. And the removal efficiency of copper using nanobubble water(NBW) and distilled water(DW) were compared and analyzed through a batch desorption test. As a result, it is confirmed that nanobubble which was fabricated by compression-dissolution type generator can exist for more than 14 days. The results of batch test show that copper removal of NBW was higher than that of DW irrespectively to soil type and increased as solid-liquid ratio and contact time increased, respectively. According to the pH change, the removal of copper on sand was higher on the acid side but the removal difference was slightly lower on the clay. It is considered that a high efficiency of NBW in copper removal is due to the large surface area and high zeta-potential of nanobubbles. Therefore, the nanobubble can be applied to soil remediation for heavy-metal contaminated soil as an eco-friendly enhancer.

A STUDY ON THE PHYSICAL PROPERTIES AND COLOR STABILITY OF MAXILLOFACIAL PROSTHETIC SILICONE MATERIAL (악안면 보철용 실리콘의 물리적 특성 및 색조안정성에 관한 연구)

  • Park, Chan-Jin;Kim, Chang-Whe;Kim, Yung-Soo
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.35 no.2
    • /
    • pp.330-343
    • /
    • 1997
  • Extraoral maxillofacial prostheses are essential for restoring facial structures that are lost as a result of congenital missing, injuries from accidents, surgical treatments of head and neck cancer. Recently, silicone is the most useful material for this purpose and is more advantageous than other maxillofacial prosthetic materials. However, there are some problems for long-term usage of silicone prostheses due to tear and color change. These are major contributing environmental factors to those problems that are such as ultraviolet light, cleansing agents, changes in humidity and successive adhesion and removal. The aim of this study is to evaluate the physical properties and color changes of maxillofacial prosthetic silicone material by those environmental factors using A-2186 silicone material (Factor II, USA) and two pigments, cadmium yellow medium and cosmetic red. Aluminium molds were fabricated according to the ASTM No. D412 & D624 specifications and resulted specimens from molds were fabicated and treated as follows. Control group and experimental I group were fabricated with 0.1% wt. pigment mixing in silicone elastomer and II-1 group, II-2 group of experimental II group were fabricated with 0.2%, 0.3% wt. pigment mixing in silicone elastomer, respectively. Control group was kept in darkroom at room temperature, I-1 group was kept under natural sunlight during 1week, I-2 group was soaked in 20% soap water during 1wk. I-3 group was successively adhered and removed 200 times on inner region of arm using Daro adhesive-33. Experimental II groups were kept in darkroom at room temperature. Instron universal testing machine was used to measure the % elongation, tensile strength, tear strength of control, experimental I, II groups and reflectance spectrophotometer(COLOR EYE-3000, Macbeth, USA) was used to measure the color differences between control group and experimental I group. The results were as follows : 1. When compared with control group, natural weathering group and 20% soap-water soaking group had no significant differences in % elongation(p>0.05). 2. 200 times successive adhesion and removal group, 0.2% wt. pigment group and 0.3% wt. pigment group had significant decreases in % elongation(p<0.05). 3. Natural weathering group, 20% soap-water soaking group and 200 times successive adhesion and removal group had no significant differences in tensile strength (p>0.05). 4. 0.2%, 0.3% wt. pigment groups had significant decreases in tensile strength(p<0.05). 5. Values of all experimental groups were decreased in tear strength. and 200 times successive adhesion and removal group had significant decrease in tear strength(p<0.05). 6. Natural weathering group and 20% soap-water soaking group had significant color differences(${\Delta}E$) and it could be detectable to naked eye(p<0.05). 7. Color differences between control group and 200 times adhesion and removal group were not detectable to the naked eye (${\Delta}E<1.0$).

  • PDF

Effects of Several Natural Medicines on Alkaline Phosphatase Synthesis in MC3T3-E1 Cells (수 종의 생약제제가 MC3T3-E1 세포의 염기성 인산분해효소 합성에 미치는 영향)

  • Kim, Dae-Kyum;Kim, Tak;Pi, Sung-Hee;Kim, Hyun-A;Choi, Kwang-Soo;You, Hyung-Keun;Shin, Hyung-Shik
    • Journal of Periodontal and Implant Science
    • /
    • v.29 no.4
    • /
    • pp.751-765
    • /
    • 1999
  • Several growth factors and polypeptidesare not commonly yet used for regenerators of bone tissue or alveolar bone because of the insufficiency of studies on their side effects, genetic engineering for mass production and stability for clinical application. Recently, many natural medicines, which have advantage of less side effects and possibility of long-term use, have been studied for their capacity and effects of anti-bacterial, anti-inflammatory and regenerative potential of periodontal tissues. Olibanum, Myrrha, Phlomis Radix, and Cimicifugae Rhizoma have been traditionally used as a drug for treatment of bone disease in oriental medicine. The objective of this study was to examine the ability of alkaline phosphatase(ALP) synthesis of rat calvarial osteoblast(MC3T3-E1) when several natural medicines were supplemented. MC3T3-E1 cells were cultured with ${\alpha}$-MEM(negative control), dexamethasone(positive control), and each natural medicines for 3 and 5 days. And then ALP synthesis was measured by spectrophotometer for enzyme activity and by naphthol AS-BI staining for morphometry. All of the natural medicines induced higher activity of ALP synthesis than the negative controls. Especially Olibanumind uced the higher activity than the positive controls (p<0.05). In the aspects of culturing time, except Cimicifugae Rhizoma, the natural medicines induced higher activity of ALP synthesis at 5 days than at 3 days (p<0.05). In morphometry, all of the natural medicines showed statistical significance compared to the negative control (p<0.05). Myrrha a n d Phlomis Radix showed larger positively stained area at 5days than at 3 days, whereas the others did not showed the difference between at 5 and at 3 days(p<0.05). These results indicate that several natural medicines have an inducing ability of ALP synthesis in MC3T3-E1 cells.

  • PDF

PCR-DGGE Analysis of the Fungal Community of Red-pepper Fields Utilizing Eco-friendly Farming Methods (PCR-DGGE를 이용한 친환경 농법 적용 고추경작지 내 진균의 군집 다양성 분석)

  • Jung, Byung-Kwon;Kim, Gwang-Seop;Song, Jin-Ha;Kim, Sang-Dal
    • Microbiology and Biotechnology Letters
    • /
    • v.41 no.3
    • /
    • pp.292-299
    • /
    • 2013
  • In this study, we analyzed the changes in fungal populations of red-pepper fields employing eco-friendly farming methods, such as microbial agents and crop rotation, by using polymerase chain reactions coupled with denaturing gradient gel electrophoresis (PCR-DGGE). Primer specific for fungi were used to determine the contribution of domains to the microbial community. Analysis of planted and non-planted soil samples applying PCR-DGGE technology offered evaluation of long-term patterns in fungal species richness. To evaluate the stability of DGGE patterns from different soils, comparison of planted and non-planted soil samples were compared using PCR-DGGE. The number of DNA fragments obtained from all planted soil samples by DGGE separation was far greater (14 to 15 bands) than that of the non-planted soil samples (3 to 4 bands). In addition, 14 bands were observed from crop continuation soil treated with agrochemicals and 18 bands from crop rotation soil treated with microbial agents. The PCR-DGGE analysis suggests that the use of crop rotation and microbial agents benefits the fungal community more than crop continuation using agrochemicals. These results indicate that crop rotation with microbial agents was better able to support beneficial organisms, enable more effective biological control and maintain a healthier balance of nutrients, organic matter and microorganisms.

Characteristics of Creep Deformation Behavior of Granite under Uniaxial Compression (단축압축하중을 받는 대전 화강암의 크립 변형거동 특성에 관한 연구)

  • 홍지수;전석원
    • Tunnel and Underground Space
    • /
    • v.14 no.1
    • /
    • pp.69-77
    • /
    • 2004
  • Investigation of the time-dependent behavior of rock and the associated mechanisms are of key interest in long-term stability analysis of many engineering applications. In this study, creep tests were performed on Daejeon granite samples of 25.4mm diameter under uniaxial compression at varying stress levels. The effect of moisture was investigated by testing both air-dried and fully water-saturated samples. The creep behavior of Daejeon granite exhibited three distinctive stages of primary, secondary and tertiary creep. The ultimate strength of granite under a constant stress decreased considerably with time. Saturation and immersion of the test specimen in water markedly increased the total creep strain as well as the secondary creep rate. The experimental creep curves are fitted to Burger's model as well as two other empirical models suggested by previous researchers. A number of the parameters determined for each model are dependent on stress and influenced by the presence of water. Based on the experimental results, an empirical relation between the applied stress and the time-dependent strain is established separately for each air-dried and fully water-saturated Daejeon granite.

The Effects of SO2 and NH3 on the N2O Reduction with CO over MMO Catalyst (MMO 촉매와 CO 환원제에 의한 N2O 분해에서 SO2 및 NH3 영향 연구)

  • Chang, Kil Sang;You, Kyung-Chang
    • Applied Chemistry for Engineering
    • /
    • v.20 no.6
    • /
    • pp.653-657
    • /
    • 2009
  • Nitrous oxide is a typical greenhouse gas which is produced from various organic or fossil fuel combustion processes as well as chemicals producing plants. $N_2O$ has a global worming potential of 310 times that of $CO_2$ on per molecule basis, and also acts as an ozone depleting material in the stratosphere. However, its removal is not easy for its chemical stability characteristics. Most SCR processes with several effective reducing agents generally require the operation temperature higher than $450^{\circ}C$, and the catalytic conversion becomes decreased significantly when NOx is present in the stream. Present experiments have been performed to obtain basic design data of actual application concerning the effects of $SO_2$ and $NH_3$ on the interim and long term activities of $N_2O$ reduction with CO over the mixed metal oxide (MMO) catalyst derived from a hydrotalcite-like compound precursor. The MMO catalysts used in the experiments, have shown prominent activities displaying full conversions of $N_2O$ near $200^{\circ}C$ when CO is introduced. The presence of $SO_2$ is considered to show no critical behavior as can be met in the $NH_3$ SCR DeNOx systems and the effect of $NH_3$ is considered to play as mere an impurity to share the active sites of the catalysts.