• Title/Summary/Keyword: turn over

Search Result 710, Processing Time 0.026 seconds

Application trend of unmanned aerial vehicle (UAV) image in agricultural sector: Review and proposal (농업분야 무인항공기 영상 활용 동향: 리뷰 및 제안)

  • Park, Jin-Ki;Das, Amrita;Park, Jong-Hwa
    • Korean Journal of Agricultural Science
    • /
    • v.42 no.3
    • /
    • pp.269-276
    • /
    • 2015
  • Unmanned Aerial Vehicle (UAV) has several advantages over conventional remote sensing techniques. They can acquire high-resolution images quickly and repeatedly. And with a comparatively lower flight altitude, they can obtain good quality images even in cloudy weather. In this paper, we discussed the state-of-the-art of the domestic and international use of UAV in agricultural sector as well as assessed its utilization and applicability for agricultural environment in Korea. Association of robotic, computer vision and geomatic technologies have established a new paradigm of low-altitude aerial remote sensing that has now been receiving attention from researchers all over the world. In a field study, it has been found that use of UAV imagery in an agricultural subsidy program can reduce the farmers' complain and provide objective evidence. UAV high resolution photography can also be helpful in monitoring the disposal zone for animal carcasses. Due to its expeditiousness and accuracy, UAV imagery can be a very useful tool to evaluate the damage in case of an agricultural disaster for both parties insurance companies and the farmers. Also high spatial and temporal resolution in UAV system can increase the prediction accuracy which in turn help to maintain the agricultural supply and demand chain.

A Cost-Effective, Single-Phase Line-Interactive UPS System that Eliminates Inrush Current Phenomenon for Transformer-Coupled Loads

  • Bukhari, Syed Sabir Hussain;Atiq, Shahid;Lipo, Thomas A.;Kwon, Byung-il
    • Journal of Electrical Engineering and Technology
    • /
    • v.11 no.3
    • /
    • pp.675-682
    • /
    • 2016
  • Sudden voltage drops and outages frequently disturb the operation of sensitive loads for domestic, commercial, and industrial use. In some cases, these events may even impair the functioning of relevant equipment. To maintain power under such conditions, a UPS system is usually installed. Once a disturbance happens at the grid side, the line-interactive UPS system takes over the load to prevent an interruption. But, due to magnetic saturation of the transformer, a significant inrush current may occur for the transformer-coupled loads during this transition. The generation of such transient currents may in turn decrease the line voltage and activates over-current protecting devices of the system. In this work, a cost-effective, line-interactive UPS system is proposed that eliminates the inrush current phenomenon associated with transformer-coupled loads. The strategy was implemented by connecting a standard current-regulated voltage source inverter (CRVSI) to the secondary winding of the load transformer. During any transient condition at the grid side, the load current is monitored and regulated to achieve either seamless compensation of the load current or complete transferal of load from grid to the inverter. Experimental results were obtained for a prototype under all possible operating conditions so as to validate the performance of the proposed topology.

Security and Authentication System for Bluetooth Mobile Phone (블루투스 모바일 폰을 위한 보안인증 시스템)

  • S.P, Balakannan;Lee, Moon-Ho;B, Karthik.
    • Proceedings of the KIEE Conference
    • /
    • 2007.04a
    • /
    • pp.261-263
    • /
    • 2007
  • Authentication is a mechanism to establish proof of identities, the authentication process ensure that. Who a particular user is. Nowadays PC and laptop user authentication systems are always done once a hold until s explicitly revoked by the user, or asking the user to frequently reestablish his identity which encouraging him to disable authentication. Zero-Interaction Authentication (ZIA) provides solution to this problem. In ZIA,. a user wears a small authentication token that communicates with a laptop over a short-range, wireless link. ZIA combine authentication with a file encryption. Here we proposed a Laptop-user Authentication Based Mobile phone (LABM). In our model of authentication, a user uses his Bluetooth-enabled mobile phone, which work as an authentication token that provides the authentication for laptop over a Bluetooth wireless link, m the concept of transient authentication with our combining It with encryption file system. The user authenticate to the mobile phone infrequently. In turn, the mobile phone continuously authenticates to the laptop by means of the short-range, wireless link.

  • PDF

Characteristic Study for Defect of Top Si and Buried Oxide Layer on the Bonded SOI Wafer (Bonded SOI wafer의 top Si과 buried oxide layer의 결함에 대한 연구)

  • Kim Suk-Goo;Paik Un-gyu;Park Jea-Gun
    • Korean Journal of Materials Research
    • /
    • v.14 no.6
    • /
    • pp.413-419
    • /
    • 2004
  • Recently, Silicon On Insulator (SOI) devices emerged to achieve better device characteristics such as higher operation speed, lower power consumption and latch-up immunity. Nevertheless, there are many detrimental defects in SOI wafers such as hydrofluoric-acid (HF)-defects, pinhole, islands, threading dislocations (TD), pyramid stacking faults (PSF), and surface roughness originating from quality of buried oxide film layer. Although the number of defects in SOI wafers has been greatly reduced over the past decade, the turn over of high-speed microprocessors using SOI wafers has been delayed because of unknown defects in SOI wafers. A new characterization method is proposed to investigate the crystalline quality, the buried oxide integrity and some electrical parameters of bonded SOI wafers. In this study, major surface defects in bonded SOI are reviewed using HF dipping, Secco etching, Cu-decoration followed by focused ion beam (FIB) and transmission electron microscope (TEM).

Development of 3.0[kW] class Fuel Cell Power Conversion System(I) (3[kW]급 연료전지용 전력변환장치(I)의 개발)

  • Mun, S.P.;Kwon, S.K.;Suh, K.Y.;Kim, Y.M.;Ryu, J.Y.
    • Proceedings of the KIEE Conference
    • /
    • 2006.07b
    • /
    • pp.1207-1208
    • /
    • 2006
  • Recently, a fuel cell with low voltage and high current output characteristics is remarkable for new generation system. It needs both a DC-DC step-up converter and DC-AC inverter to be used in fuel cell generation system. Therefor, this paper, consists of an isolated DC-DC converter to boost the fuel cell voltage 380[VDC] and a PWM inverter with LC filter to convent the DC voltage to single-phase 220[VAC]. Expressly, a tapped inductor filter with freewheeling diode is newly implemented in the output filter of the proposed high frequency isolated ZVZCS PWM DC-DC converter to suppress circulating current under the wide output voltage regulation range, thus to eliminate the switching and transformer turn-on/off over-short voltage or transient phenomena. Besides the efficiency of 93-97[%] is obtained over the wide output voltage regulation ranges and load variations.

  • PDF

Analysis of Traffic Accident Severity by Aging Level (고령화 수준별 교통사고 심각성 분석)

  • Kim, Tae Yang;Park, Byung Ho
    • Journal of the Korean Society of Safety
    • /
    • v.33 no.4
    • /
    • pp.105-110
    • /
    • 2018
  • Korea has entered to 'aged society', which the elderly people over 65 years old is over 14% of total population. This paper aims to analyze the traffic accident by aging level. In pursuing the above, this paper focuses on modeling the traffic accident severity based on three aging levels. The main results are as follows. First, the ratio of fatal and serious injured persons (FSI) is judged to increase according to increasing aging level. Second, the null hypothesis that there is no difference in FSI among three aging levels (aging, aged, and super-aged) is rejected. Four accident severity generalized linear models which are all statistically significant have been developed. Third, the common variables are analyzed to be median age, the number of hospital beds per persons, and turn signal usage ratio. Fourth, the differentiated traffic safety policies fitted to aging levels are required. The enforcement of traffic law violation and safety enhancement of motorcycle in the region of 'aging society', improvement of traffic facilities in the region of 'aged society', and expansion of transportation facilities in the region of 'super-aged society' are evaluated to be indispensable.

A Model for Production Planning in a Multi-item Production System -Multi-item Parametric Decision Rule- (다품목(多品目) 생산체제(生産體制)의 생산계획(生産計劃)을 위한 모델)

  • Choe, Byeong-Gyu
    • Journal of Korean Institute of Industrial Engineers
    • /
    • v.1 no.2
    • /
    • pp.27-38
    • /
    • 1975
  • This paper explores a quantitative decision-making system for planning production, inventories and work-force in a multi-item production system. The Multi-item Parametric Decision Rule (MPDR) model, which assumes the existence of two types of linear feed-back rules, one for work-force level and one for production rates, is basically an extension of the existing method of Parametric Production Planning (PPP) proposed by C.H. Jones. The MPDR model, however, explicitly considers the effect of manufacturing progress and other factors such as employee turn-over, difference in work-days between month etc., and it also provides decision rules for production rates of individual items. First, the cost relations of the production system are estimated in terms of mathematical functions, and then decision rules for work-force level and production rates of individual items are establised based upon the estimated objective cost function. Finally, a direct search technique is used to find a set of parameters which minimizes the total cost of the objective function over a specified planning horizon, given estimates of future demands and initial values of inventories and work-force level. As a case problem, a hypothetical decision rule is developed for a particular firm (truck assembly factory).

  • PDF

KROSS: Probing the Tully-Fisher Relation over Cosmic Time

  • Bureau, Martin
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.43 no.2
    • /
    • pp.35.2-35.2
    • /
    • 2018
  • Using the K-band Multi-object Spectrograph (KMOS) at the Very Large Telescope (VLT), the KMOS Redshift One Spectroscopic Survey (KROSS) has gathered integral-field data for ~800 star-forming galaxies at a redshift z~1, when the universe was roughly half its current age and forming the bulk of its stars. With spatially-resolved observations, KROSS reveals galaxies that are both gas-rich and highly turbulent. It is possible to derive the observed and baryonic Tully-Fisher (luminosity - rotation velocity) relations, thus constraining the mass-to-light ratios and total (luminous + dark) masses of the galaxies. This in turn highlights the dependence of the relation zero-point on the degree of rotational support of the galaxies (rotational velocity to velocity dispersion ratio). By degrading and analogously analysing integral-field data of hundreds of local galaxies from the Sydney-AAO Multi-object Integral-field Spectrograph (SAMI) survey, a robust comparison z=0 Tully-Fisher relation can also be derived, thus further constraining the luminous and dark mass growth of disk galaxies over the last 7 billions years. This unique comparison also reveals that systematic effects associated with sample selection and analysis methods are as large as the effects expected from cosmological evolution, and thus that most other comparisons employing heterogeneous data and/or methods can safely be ignored.

  • PDF

A New Cryptographic Algorithm for Safe Route Transversal of Data in Smart Cities using Rubik Cube

  • Chhabra, Arpit;Singhal, Niraj;Bansal, Manav;Rizvi, Syed Vilayat
    • International Journal of Computer Science & Network Security
    • /
    • v.22 no.8
    • /
    • pp.113-122
    • /
    • 2022
  • At the point when it is check out ourselves, it might track down various information in each turn or part of our lives. Truth be told, information is the new main thrust of our advanced civilization and in this every day, "information-driven" world, security is the significant angle to consider to guarantee dependability and accessibility of our organization frameworks. This paper includes a new cryptographic algorithm for safe route traversal for data of smart cities which is a contemporary, non-hash, non-straight, 3D encryption execution intended for having information securely scrambled in the interim having a subsequent theoretical layer of safety over it. Encryption generally takes an information string and creates encryption keys, which is the way to unscramble as well. In the interim in another strategy, on the off chance that one can sort out the encryption key, there are opportunities to unravel the information scrambled inside the information string. Be that as it may, in this encryption framework, the work over an encryption key (which is created naturally, henceforth no pre-assurance or uncertainty) just as the calculation produces a "state" in a way where characters are directed into the Rubik block design to disregard the information organization.

New proposal for skin grafts on tendon-exposed wounds

  • Um, Jung Hwan;Jo, Dong In;Kim, Soon Heum
    • Archives of Plastic Surgery
    • /
    • v.49 no.1
    • /
    • pp.86-90
    • /
    • 2022
  • Performing a skin graft is not feasible for tendon-exposed defect reconstruction because tendons are fibrous connective tissues with relatively poor blood supply. This study proposes a method to effectively perform skin graft surgery in tendon-exposed wounds. A 48-year-old male patient with diabetes mellitus had a very large left dorsal foot defect (8×8 cm). The wound bed had healthy granular tissue, with tendon exposure. The tendons were turned over so that the posterior side would behave as the anterior side. The edge of the paratenon was then fixed together to the surrounding granulation tissue or dense remnant fascia using absorbable sutures, and the close granulation tissue was approximated and buried. A split-thickness skin graft was performed after 1 week. The graft site was stably taken on postoperative day 3. A small disruption was then observed at the graft site within 1 week postoperatively, but conservative treatment was continued for 1 month, after which the defect site was completely restored. This technique can increase the success rate of skin grafts for defects with tendon exposure.