• Title/Summary/Keyword: Small-scale field

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A Study on the Estimation of Proper Construction Cost for Road Pavement Maintenance Work (아스팔트포장 유지보수 적정공사비 산정방안 연구)

  • Oh, JaeHun;Song, TaeSeok;An, BangYul
    • Korean Journal of Construction Engineering and Management
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    • v.21 no.6
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    • pp.16-26
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    • 2020
  • Road Pavement Maintenance Work is generated in a variety of different field conditions, and it is difficult to calculate the construction cost because there are no detailed criteria when preparing the estimated construction cost. Unlike new pavements, Road Pavement Maintenance has to be constructed with operating vehicles, and there are many differences in productivity depending on urban areas, limited work hours, night-time, construction area, etc. To compensate for this, the standard for calculation of construction cost provides additional charges for the number of lanes, residential areas, working hours, and night work, but it applied differently depending on construction officials. In this study, construction cost estimation standards that can properly reflect the conditions of the site was investigated for major types of Road Pavement Maintenance work. The site was investigated and analyzed mainly for many construction sites with 'overlay of asphalt after cutting', 'restore surface', 'repair of pavement', and 'recovery of roadway'. The criteria for the application of construction volume separately according to working hours, public places, and land area including extra charges for basic downtown and residential area. The hours of operation were divided into three types(7 hours, 5 hours, 3 hours) excluding movement and preparation time, and each type provided a coefficient for dividing the area of the construction site into five types. The construction cost calculation method based on the construction purpose is site conditions is proposed accordingly, and it is deemed that a plan for the designer to calculate the construction cost has been prepared in consideration of the site conditions.

Opportunities for Agricultural Water Management Interventions in the Krishna Western Delta - A case from Andhra Pradesh, India

  • Kumar, K. Nirmal Ravi
    • Agribusiness and Information Management
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    • v.9 no.1
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    • pp.7-17
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    • 2017
  • Agricultural water management has gained enormous attention in the developing world to alleviate poverty, reduce hunger and conserve ecosystems in small-scale production systems of resource-poor farmers. The story of food security in the $21^{st}$ century in India is likely t o be closely linked to the story of water security. Today, the water resource is under severe threat. The past experiences in India in general and in Andhra Pradesh in particular, indicated inappropriate management of irrigation has led to severe problems like excessive water depletion, reduction in water quality, water logging, salinization, marked reduction in the annual discharge of some of the rivers, lowering of ground water tables due to pumping at unsustainable rates, intrusion of salt water in some coastal areas etc. Considering the importance of irrigation water resource efficiency, Krishna Western Delta (KWD) of Andhra Pradesh was purposively selected for this in depth study, as the farming community in this area are severely affected due to severe soil salinity and water logging problems and hence, adoption of different water saving crop production technologies deserve special mention. It is quite disappointing that, canals, tube wells and filter points and other wells could not contribute much to the irrigated area in KWD. Due to less contribution from these sources, the net area irrigated also showed declining growth at a rate of -6.15 per cent. Regarding paddy production, both SRI and semi-dry cultivation technologies involves less irrigation cost (Rs. 2475.21/ha and Rs. 3248.15/ha respectively) when compared to transplanted technology (Rs. 4321.58/ha). The share of irrigation cost in Total Operational Cost (TOC) was highest for transplanted technology of paddy (11.06%) followed by semi-dry technology (10.85%) and SRI technology (6.21%). The increased yield and declined cost of cultivation of paddy in SRI and semi-dry production technologies respectively were mainly responsible for the low cost of production of paddy in SRI (Rs. 495.22/qtl) and semi-dry (Rs. 532.81/qtl) technologies over transplanted technology (Rs. 574.93/qtl). This clearly indicates that, by less water usage, paddy returns can be boosted by adopting SRI and semi-dry production technologies. Both the system-level and field-level interventions should be addressed to solve the issues/problems of water management. The enabling environment, institutional roles and functions and management instruments are posing favourable picture for executing the water management interventions in the State of Andhra Pradesh in general and in KWD in particular. This facilitates the farming community to harvest good crop per unit of water resource used in the production programme. To achieve better results, the Farmers' Organizations, Water Users Associations, Department of Irrigation etc., will have to aim at improving productivity per unit of water drop used and this must be supported through system-wide enhancement of water delivery systems and decision support tools to assist farmers in optimizing the allocation of limited water among crops, selection of crops based on farming situations, and adoption of appropriate alternative crops in drought years.

Image-based Proximity Warning System for Excavator of Construction Sites (건설현장에 적합한 영상 기반 굴삭기 접근 감지 시스템)

  • Jo, Byung-Wan;Lee, Yun-Sung;Kim, Do-Keun;Kim, Jung-Hoon;Choi, Pyung-Ho
    • The Journal of the Korea Contents Association
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    • v.16 no.10
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    • pp.588-597
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    • 2016
  • According to an annual industrial accident report from Ministry of Employment of Labor, among the various types of accidents, the number of accidents from construction industry increases every year with the percentage of 27.56% as of 2014. In fact, this number has risen almost 3% over the last four years. Currently, among the industrial accidents, heavy machinery causes most of the tragedy such as collision or narrowness. As reported by the government, most of the time, both heavy machinery drivers and workers were unaware of each other's positions. Nowadays, however when society requires highly complex structures in minimal time, it is inevitable to allow heavy construction equipments running simultaneously in a construction field. In this paper, we have developed Approach Detection System for excavator in order to reduce the increasing number. The imaged based Approach Detection System contains camera, approach detection sensor and Around View Monitor (AVM). This system is also applicable in a small scale construction fields along with other machineries besides excavators since this system does not require additional communication infra such as server.

The Effects of Management Consulting Quality and Consultant Capability on Entrepreneurial Firms' Performance (창업기업의 경영성과에 있어서 컨설팅품질과 컨설턴트역량의 영향에 대한 연구: 흡수능력과 자원역량의 매개효과를 중심으로)

  • Yoon, Ki-Chang
    • Journal of Distribution Science
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    • v.14 no.5
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    • pp.81-89
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    • 2016
  • Purpose - Prior researches have empirically focused on the effect of management consulting quality and consultant capability on entrepreneurial firms' performance. This study, however, focused on investigating the moderating role of absorptive capacity and resource capability between management consulting and entrepreneurial firms' performance. So, this study investigated the relationship among consulting quality, consultant capability, absorptive capacity, resource capability, and entrepreneurial firms' performance from the resource based view (RBV). Especially, this study focused on the mediating role of absorptive and resource capability in relational structure of entrepreneurial firms' dimensions. Research design, data, and methodology - In this study, research hypotheses and model are established by the prior researches from the fields of strategic management and entrepreneurial behavior. Concretely, H1~H4 are the relationship between consulting (consulting quality, consultant capability) and innovation (absorptive capacity, resource capability); H5 is the relationship between absorptive capacity and resource capability; and H6~H7 are the relationship between innovation (absorptive capacity, resource capability) and management performance. The data was collected 207 copies from entrepreneurial firms in South Korea. These firms were established in January 2014 and maintained by November 2015 in high-tech industry. The questionnaire was consisted of five dimensions; consulting quality, consultant capability, absorptive capacity, resource capability, and management performance. Each dimension measured multi items on a 5-point Likert scale. The hypotheses and research model are analyzed using structural equation modeling (SEM) with AMOS 22. Results - The results of this study are as follows. 1) Consulting quality significantly influenced on the absorptive capacity of entrepreneurial firms. 2) But, consultant capability did not influence on the absorptive capacity of entrepreneurial firms. 3) Consulting quality and consultant capability significantly influenced on the resource capability of entrepreneurial firms. 4) Absorptive capacity significantly influenced on the resource capability of entrepreneurial firms; 5) Absorptive capacity did not significantly influence on the management performance of entrepreneurial firms. 6) Resource capability, however, significantly influenced on the management performance of entrepreneurial firms. By these results, absorptive capacity of entrepreneurial firms had a mediating role partly among consulting quality, consultant capability, and management capability. The resource capability of entrepreneurial firms had a mediating role among consulting quality, consultant capability, and management capability, perfectly. Conclusions - According to this study, the high level of consulting quality and consultant capability may enforce the resource capability of entrepreneurial firms. It means, practically, that external knowledge is a driver for innovation, and then the innovation effects on the management performance of entrepreneurial firms. So, at the initial stage, the management consulting programs are very important to entrepreneurial firms and should be conceived as an essential element. This study may contribute to the advancement of academic in field of new start business, small business, or venture business based on resources, especially the role of absorptive capacity and resource capability between consulting programs and management performance. However, this study has some limitations. They are the measurement of consulting quality's items, cross-sectional research, and the limitation of concept and industry.

A Study on the Factors of the Hardware Cost Estimation for Service Robot Development (서비스 로봇 개발의 하드웨어 비용추정을 위한 항목 도출에 관한 연구)

  • Lee, Jungsoo;Sohn, Dongseop;Choi, Yeon-Seo;Park, Myeongjun;Min, Jeongtack
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.5
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    • pp.35-44
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    • 2018
  • The purpose of this study was to derive the factors that affect the development cost and the priority/weight of effectiveness in the pre-development stage of a service robot to estimate the development cost. In particular, the functions of service robots vary according to the field of application, and their prices are not only different but most of them are small-scale production; hence, a cost estimation is necessary. In this research, the factors affecting the service robot development cost in the process of service robot development and adding functions are classified as a functional factor while the factors that affect the entire development cost due to environmental causes, in which the service robot is operated or in the development process, are classified as an adjustment factor. The FGI was conducted to derive the factors and a Delphi survey was conducted among 84 domestic experts to determine the weights of the factors. As a result of the analysis, six functional factors (41 detailed criteria) and five adjustment factors (17 criteria) were derived, the cost weight and rank of the factors were suggested. This study suggests that the development cost of the service robot can be used as a decision-making strategy to select the operation functions in the development process, and can be utilized as an essential tool for the service robot development.

Stability Analysis of Excavation Slope on Soft Ground (연약지반 굴착사면의 안정해석)

  • Kang, Yea Mook;Cho, Jae Hong;Kim, Yong Seong;Kim, Ji Hoon
    • Korean Journal of Agricultural Science
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    • v.23 no.1
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    • pp.25-38
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    • 1996
  • To investigate the stability problem of irrigation-drainage channel excavation slope on soft ground, analyzed the behavior of the soft ground with excavation slope by the limit equilibrium method and the finite element method, and compared with field tests. The results of this study were summarized as follows; 1. When rapid drawdown the water level, the crack was occurred by the effect of the excess pore water pressure, and the pore water pressure was decreased slowly. 2. As the width of excavation was larger, the crack width was larger. And, excavated depth was deeper, the progressive failure was appeared. 3. When the soft ground excavation was small-scale, the minimum safety factor was more effected by cohesion(1.0, 1.5, 2.0, 2.5, 3.0) than excavated slope inclination(1:l, 1:1.5, 1:2). 4. As excavation was progressed, the settlement occurred on the top-slope due to plastic domain, and heaving was occurred at the bottom of excavation. 5. The maximum shear stress was appeared greatly as the base part of slope went down. Because of the increase of the maximum shear stress, tension area occurred and local failure possibility was increased. 6. As the excavation depth was increased, the maximum shear strain was appeared greatly at the base of slope and distribution pattern was concentrated beneath the middle of slope.

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Strength Development of Fiber Reinforced Lean Concrete Using Fly Ash and Reject Ash under Different Compaction Methods including Small Scale Roller Vibrator (플라이애쉬와 리젝트애쉬를 활용한 섬유보강 빈배합 콘크리트의 강도 특성 및 롤러다짐을 활용한 현장적용 실험)

  • Kim, Seung-Won;Jang, Young-Jae;Park, Young-Hwan;Park, Cheol-Woo
    • Journal of the Korea Concrete Institute
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    • v.24 no.5
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    • pp.543-551
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    • 2012
  • Road pavements in Korea generally show shorter service life than the predicted one. There are many reasons for this phenomenon including increased traffic load and other attacks from exposure conditions. In order to extend a service life and upgrade the pavement, a new multi-functional composite pavement system is being developed in Korea. This study is to investigate the performances of fiber-reinforced lean concrete for pavement base. This study considered mineral admixtures of fly ash and reject ash. The reject ash is defined as ash that does not meet the specifications for fly ash so that it cannot be used as a supplemental material for cement replacement. Due to the inherent property of lean concrete, compaction during the fabrication of specimens is a key factor. Therefore, this study suggests an appropriate compaction method. From the test results, the compressive strengths of the concrete satisfied the required limit of 5 MPa at 7 days. When a compaction roller was used to mimic actual field conditions, the strength development seemed to be influenced by the compaction energy rather than hydration of cement itself.

Current Status of Nanotechnology Development for Space Exploration (우주탐사용 나노기술 개발 동향)

  • Lee, Ho-Sung;Chae, Yeon-Seok
    • Current Industrial and Technological Trends in Aerospace
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    • v.6 no.1
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    • pp.90-98
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    • 2008
  • Nanotechnology(NT) refers to a field of advanced micro-technology covering the creation and manufacturing of materials on the atomic and molecular scale and requires interdisciplinary study with various fields including materials science, physics, chemistry, electronics and others. Whileas nanotechnology is a kind of micro and small scaled science, space technology(ST) is one of the larger and system technologies utilizing broad fields of mechanical, materials, electronics and communication technologies. It is necessary to select and concentrate the functional items of nanotechnology for efficient application to be utilized in space technology, due to the cross-sectional characteristics of nanotechnology within nanomaterials, nanoelectronics, and nanomanufacturing. This paper provides the current state of art of nanotechnology in space technology by evaluating NASA's activities and the 9th frame of the project ANTARES(Analysis of Nanotechnology Applications in Space Developments and Systems) with the support of the German Aerospace Center (DLR), Space Flight Management, Division Technology for Space Systems and Robotics. It has shown that it is necessary to apply nanotechnology to space technology in order to achieve international competitiveness, for the nanotechnology can bring the previously impossible things to reality. Since KARI plans to send an unmanned probe to the moon's orbit and land a probe on the moon's surface in 2025, it is urgently needed to incorporate nanotechnology to national space development plan.

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A Study on the Integration of Airborne LiDAR and UAV Data for High-resolution Topographic Information Construction of Tidal Flat (갯벌지역 고해상도 지형정보 구축을 위한 항공 라이다와 UAV 데이터 통합 활용에 관한 연구)

  • Kim, Hye Jin;Lee, Jae Bin;Kim, Yong Il
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.38 no.4
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    • pp.345-352
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    • 2020
  • To preserve and restore tidal flats and prevent safety accidents, it is necessary to construct tidal flat topographic information including the exact location and shape of tidal creeks. In the tidal flats where the field surveying is difficult to apply, airborne LiDAR surveying can provide accurate terrain data for a wide area. On the other hand, we can economically obtain relatively high-resolution data from UAV (Unmanned Aerial Vehicle) surveying. In this study, we proposed the methodology to generate high-resolution topographic information of tidal flats effectively by integrating airborne LiDAR and UAV point clouds. For the purpose, automatic ICP (Iterative Closest Points) registration between two different datasets was conducted and tidal creeks were extracted by applying CSF (Cloth Simulation Filtering) algorithm. Then, we integrated high-density UAV data for tidal creeks and airborne LiDAR data for flat grounds. DEM (Digital Elevation Model) and tidal flat area and depth were generated from the integrated data to construct high-resolution topographic information for large-scale tidal flat map creation. As a result, UAV data was registered without GCP (Ground Control Point), and integrated data including detailed topographic information of tidal creeks with a relatively small data size was generated.

Characteristics and Drug Release Profiles of Multilamellar Vesicle(MLV) and Microemulsified Liposome(MEL) Entrapped 5-Fluorouracil and Its derivatives (5-Fluorouracil과 그 유도체를 봉입한 Multilamellar Vesicle(MLV)과 Microemulsified Liposome(MEL)의 특성 및 약물방출 거동)

  • Jee, Ung-Kil;Park, Mok-Soon;Lee, Gye-Won;Lyu, Yeon-Geun
    • Journal of Pharmaceutical Investigation
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    • v.25 no.3
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    • pp.249-264
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    • 1995
  • Although liposome has many advantages as a pharmaceutical dosage form, its application in the industrial field has been limited because of some problems such as preparation method, reproducibility, scale-up, stability and sterilization etc. Liposomes prepared by microemulsification method had defined size, narrow size distribution, reproducibility and high entrapment efficiency. For enhancing the stability, the dry form of liposome was recommended. These types of liposome are proliposome and freeze-dried liposome. The liposome must have some properties for preparing of freeze-dried liposome; small size $(50{\sim}200\;nm)$, narrow size distribution and cryoprotectant. In this experiment, the liposomes containing 5-Fluorouracil(5-FU) and its prodrug(pentyl-5-FU-1-acetate; PFA, hexyl-5-FU-1-acetate; HFA) were made with soybean phosphatidylcholine, cholesterol, stearylamine(SA) and dicetyl phosphate(DCP) employing hydration method or microemulsification method using $Microfluidizer^{TM}$. Both or liposome types were MLV and MEL. After preparation, freeze drying and rehydration were performed. In the process of freezing, trehalose(Tr) was added as a cryoprotectant. Their evaluation methods were as follows; entrapment efficiency, mean particle size and size distribution, dissolution test, retain of entrapment efficiency and turbidity after freeze-drying. The results are summarized as belows. The entrapment efficiency of 5-FU was dependent on total lipid concentration and cholesterol content but that of PFA and HFA was decreased when cholesterol was added. When DCP and SA were added, entrapment efficiency was decreased. As the partition coefficient of drug was increased, entrapment efficiency was increased. Under the same condition, entrapment efficiency of MEL is similar to that of MLV. The mean particle size and size distribution of MEL were smaller than those of MLV. Dissolution rates of drug from both liposome types were comparatively similar. Dissolution rates of drugs with serum and liver homogenate were faster than without these material. After preparation of liposome, free drug was removed efficiency by Dowex 50W-X4. When liposome was freeze-dried and then rehydrated in the presence of Tr, characteristics of liposome were maintained well in MEL than MLV. Tr Was used successfully as a cryoprotectant in the process of freeze drying and the optimal ratio of Tr:Lipid was 4:1(g/g).

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