• Title/Summary/Keyword: Small-scale field

Search Result 585, Processing Time 0.027 seconds

Construction of Database for Application of APEX Model in Korea and Evaluation of Applicability to Highland Field (APEX 모델의 국내 적용을 위한 데이터베이스 구축 및 고랭지 밭에 대한 적용성 평가)

  • Koo, Ja-Young;Kim, Jonggun;Choi, Soon-Kun;Kim, Min-Kyeong;Jeong, Jaehak;Lim, Kyoung Jae
    • Journal of The Korean Society of Agricultural Engineers
    • /
    • v.59 no.6
    • /
    • pp.89-100
    • /
    • 2017
  • The Agricultural Policy/Environmental eXtender (APEX) model was developed to extend EPIC's capabilities of simulating land management impacts for small-medium watershed and heterogeneous farms. APEX is a flexible and dynamic tool that is capable of simulating a wide array of management practices, cropping systems, and other land uses across a broad range of agricultural landscapes. APEX have its own agricultural environmental database including operation schedule, soil property, and weather data etc., by crops. However, agriculture environmental informations the APEX model has is all based on U.S. As this can cause malfunction or improper simulation while simulating highland field. In this study, database for APEX model to be utilized for South Korea established with 44,814 agriculture fields in Pyeongchang-gun, Korea from 2007 to 2016. And assessed domestic applicability by comparing T-P unit load criteria presented by National Institution of Environmental Research and result of APEX model. As a result of APEX model simulation, average T-P value for decade was 6.18. Average T-P of every year except 2011 was in range of 5.37~10.43 and this is being involved into criteria presented by National Institution of Environmental Research. It is analyzed that adjusting slope factor can make the model applicable for domestic agricultural environment.

A Improvement Plan for Fire Fighting Activity of Rack- Type Warehouse Based on Case Study and Field Interview (사례분석과 현장인터뷰를 통한 적층형 대형창고 소방활동 개선방안 연구)

  • Kim, Woon Hyung;Seo, Dong Hun;Ham, Eun Gu
    • Journal of the Society of Disaster Information
    • /
    • v.15 no.1
    • /
    • pp.67-75
    • /
    • 2019
  • Purpose: The purpose of this study is to suggest a systematic improvement plan for strengthening fire fighting ability of domestic rack- type warehouse buildings. Method: A fire case of small warehouse with sandwich panel structure and four design review of large warehouse with fire endurance structure were analyzed. Also, interviewed a group of 11 fire fighters who had 20 years field experience. Results: A provision of mobile equipment for initial fire fighting, accessibility of more than three sides, installation of internal entrance windows, proper placement of outdoor fire fighting equipment, image processing of fire site informations, and provide more incentives on the field commander are main factors of improvement plan. Conclusion: Effective standard operation procedures (SOP) and safety standards should be established and applied for each stage of the dispatch and on-site response considering the fire characteristics and risk factors of each warehouse by scale.

Characteristics and Geoeffectiveness of Small-scale Magnetic Flux Ropes in the Solar Wind

  • Kim, Myeong Joon;Park, Kyung Sun;Lee, Dae-Young;Choi, Cheong-Rim;Kim, Rok Soon;Cho, Kyungsuk;Choi, Kyu-Cheol;Kim, Jaehun
    • Journal of Astronomy and Space Sciences
    • /
    • v.34 no.4
    • /
    • pp.237-244
    • /
    • 2017
  • Magnetic flux ropes, often observed during intervals of interplanetary coronal mass ejections, have long been recognized to be critical in space weather. In this work, we focus on magnetic flux rope structure but on a much smaller scale, and not necessarily related to interplanetary coronal mass ejections. Using near-Earth solar wind advanced composition explorer (ACE) observations from 1998 to 2016, we identified a total of 309 small-scale magnetic flux ropes (SMFRs). We compared the characteristics of identified SMFR events with those of normal magnetic cloud (MC) events available from the existing literature. First, most of the MCs and SMFRs have similar values of accompanying solar wind speed and proton densities. However, the average magnetic field intensity of SMFRs is weaker (~7.4 nT) than that of MCs (~10.6 nT). Also, the average duration time and expansion speed of SMFRs are ~2.5 hr and 2.6 km/s, respectively, both of which are smaller by a factor of ~10 than those of MCs. In addition, we examined the geoeffectiveness of SMFR events by checking their correlation with magnetic storms and substorms. Based on the criteria Sym-H < -50 nT (for identification of storm occurrence) and AL < -200 nT (for identification of substorm occurrence), we found that for 88 SMFR events (corresponding to 28.5 % of the total SMFR events), substorms occurred after the impact of SMFRs, implying a possible triggering of substorms by SMFRs. In contrast, we found only two SMFRs that triggered storms. We emphasize that, based on a much larger database than used in previous studies, all these previously known features are now firmly confirmed by the current work. Accordingly, the results emphasize the significance of SMFRs from the viewpoint of possible triggering of substorms.

Design and Development of the SNIPE Bus System (초소형위성 SNIPE 본체 설계 및 개발)

  • Kim, Hae-Dong;Choi, Won-Sub;Kim, Min-Ki;Kim, Jin-Hyung;Kim, KiDuck;Kim, Ji-Seok;Cho, Dong-Hyun;Lee, Jaejin
    • Journal of Space Technology and Applications
    • /
    • v.2 no.2
    • /
    • pp.81-103
    • /
    • 2022
  • In this paper, the contents of the design and development process of the 6U micro-satellite Snipe (SNIPE, national name Toyosat; small scale magnetospheric and Ionospheric plasma experiment ), which was developed to observe the near-global space environment through polarization flight for the first time in Korea, were described. Snipe performs transversal flight to observe the Earth's surrounding space environment in three dimensions, and aims to simultaneously observe the space plasma density and temperature in the ionosphere, as well as temporal changes in the solar magnetic field and electromagnetic waves. In this way, it was developed by dividing it into a test certification model (EQM) and a flight model (FM) to perform the actual mission for at least six months, away from developing a cube satellite for short-term space technology verification or manpower training. Currently, Snipe, which has completed the development of a total of four FM and completed all space environment tests, is scheduled to launch 2023. In this paper, we introduce the design contents and development process of the Snipe satellite body ahead of launch, and hope that it will be a useful reference for the development of 6U-class micro-satellite for full-scale mission in Korea.

SNIPE Mission for Space Weather Research (우주날씨 관측을 위한 큐브위성 도요샛 임무)

  • Lee, Jaejin;Soh, Jongdae;Park, Jaehung;Yang, Tae-Yong;Song, Ho Sub;Hwang, Junga;Kwak, Young-Sil;Park, Won-Kee
    • Journal of Space Technology and Applications
    • /
    • v.2 no.2
    • /
    • pp.104-120
    • /
    • 2022
  • The Small Scale magNetospheric and Ionospheric Plasma Experiment (SNIPE)'s scientific goal is to observe spatial and temporal variations of the micro-scale plasma structures on the topside ionosphere. The four 6U CubeSats (~10 kg) will be launched into a polar orbit at ~500 km. The distances of each satellite will be controlled from 10 km to more than ~1,000 km by the formation flying algorithm. The SNIPE mission is equipped with identical scientific instruments, Solid-State Telescopes(SST), Magnetometers(Mag), and Langmuir Probes(LP). All the payloads have a high temporal resolution (sampling rates of about 10 Hz). Iridium communication modules provide an opportunity to upload emergency commands to change operational modes when geomagnetic storms occur. SNIPE's observations of the dimensions, occurrence rates, amplitudes, and spatiotemporal evolution of polar cap patches, field-aligned currents (FAC), radiation belt microbursts, and equatorial and mid-latitude plasma blobs and bubbles will determine their significance to the solar wind-magnetosphere-ionosphere interaction and quantify their impact on space weather. The formation flying CubeSat constellation, the SNIPE mission, will be launched by Soyuz-2 at Baikonur Cosmodrome in 2023.

Multiple Case Analysis Study on Business Model Types and Components of Startups: Focusing on Leading Overseas Smart Farm Companies (스타트업의 비즈니스 모델 유형 및 구성요소에 대한 다중 사례 분석 연구: 해외 스마트팜 선도기업을 중심으로)

  • Ahn, Mun Hyoung
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
    • /
    • v.18 no.6
    • /
    • pp.41-55
    • /
    • 2023
  • In order to secure sustainable competitiveness of startups, business model innovation is an important task to achieve competitive advantage by transforming the various elements that make up the business model. This study conducted a multi-case analysis study on leading smart farm companies around the world using an analysis framework based on business model theory. Through this, we sought to identify business model types and their constituent elements. For this, 19 companies were selected from the list of top 10 investment startups of the year for the past three years published by Agfunder, a global investment research company specializing in AgTech. Then data collection and analysis of the company cases were conducted according to the case study protocol. As a result of the study, the business model types were analyzed into four types: large-scale centralized production model, medium-to-large local distributed production model, small-scale hyperlocal modular FaaS model, and small-scale hyperlocal turnkey solution supply model. A comparative analysis was conducted on five business model components for each type, and strategic implications were derived through this. This study is expected to contribute to improving the competitiveness of domestic smart farm startups and diversifying their strategies by identifying the business models of overseas leading companies in the smart farm field using an academic analysis framework.

  • PDF

A Comparative Analysis of the Level of Occupational Health : Before and After the Subsidiary Program on Health Care Management of Small Scale Industries (영세사업장 보건관리 지원사업 실시 전후의 산업보건수준 비교 분석)

  • Jung, Hye Sun
    • Korean Journal of Occupational Health Nursing
    • /
    • v.4
    • /
    • pp.58-83
    • /
    • 1995
  • The small scale industries which have less than 30 employees occupy 86.5% of total number of industries in Korea. And though they have higher accident rate and lower environmental condition than big industries, it has been not mandatory to appointing health care manager at factory. So, from 1993, government subsidizes to the health care management of small industries. The purpose of this study is to identify the real feature of health care status in small industries, and to evaluate the level of health care management, before and after the subsidiary program. 65 small plating industries which have been managed by the same health care management support institution in 1993 were selected for study. Of the 65 industries, 3 which have not taken both environmental evaluation and health screening in 1994, and 9 which have closed were excluded from study sample. And the remaining 53 were analyzed by using the results of environmental evaluation and health screening, reported to the Ministry of Labor, before and after the subsidiary program, the analysis was done by the comparison of the two year paired data of the same industry. Over-permissible-limit rate, health screening implementation rate, above grade C rate were calculated and compared. The status of health care management ; 1. Of the sample industries, 96.9% provide protective equipment and 80.0% set up ventilating system. Protective gloves (89.2%) and protective clothing (80.0%) are widely provided, but ear plugs (4.6%) are rarely provided. 21.5% of the protective equipment are well put on, and 40.4% of the ventilating systems function well. 2. In 1993, 35 industries, 53.8% of the sample, checked working environment twice. Over-permissible-limit rates of heavy metal (12.2%), suspended particle (11.1%), noise (5.5%) were high. To put on protective equipment and to set up local ventilating system were pointed out by the examiners. 3. General health screening was done at 63.1% of the sample industries and 35.3% of total workers were examined. Specific health screening was done at 93.8% of the sample industries and 75.4% of workers were examined. 15.5% of workers was provided to be above grade C and to have digestive system disease (43.3%), circulatory disease (18.9%), and hematopoietic disease (14.2%), etc. 4. In 1993, the subsidiary program of health care management was provided in forms of health education, health counseling, and rounding check of working field. And 61.5%, 83.0%, 55.4% of sample industries respectively received it. The average visit per industry was 1.8. Comparisons of the level of occupational health before and after the subsidiary program ; 1. Over-permissible-limit rates of hazardous factors of 1993 and that of 1994 were compared. The rates of suspended particle, noise, organic solvent of 1994 (37.5%, 13.4%, 24.2% respectively) were higher than that of 1993 (25.0%, 6.0%, 6.3% respectively). In the case of acid, there was no difference between the rate of 1993 and that of 1994. Only the rate of heavy metal decreased from 12.9% in 1993 to 3.0% in 1994. 2. General health screening was done at 38.7% of the sample industries in 1993 and at 44.6% in 1994. But the implementation rate of specific health screening decreased from 72.4% in 1993 to 64.6% in 1994. 3. The implementation rate of specific health screening was analyzed by some health factors. The rate of suspended particle increased from 61.8% in 1993 to 91.2% in 1994. But the rates of the others-noise, organic solvent, heavy metal, specific chemical substances-decreased. 4. Above grade C rate in health screening increased from 27.8% in 1993 to 35.5% in 1994. But that of endocrine disorders and pulmonary disease decreased.

  • PDF

Characteristics of the Dangsan Forests at Ijeon-ri, Cheongsong-gun and Perspectives on Conservation Scheme (청송군 이전리 당산숲의 경관 특성 및 보전 방안)

  • Choi, Jai-Ung;Kim, Dong-Yeob;Rhee, Sang-Young
    • Journal of the Korean Institute of Traditional Landscape Architecture
    • /
    • v.32 no.2
    • /
    • pp.106-115
    • /
    • 2014
  • Traditional village forests called Dangsan forests represent unique cultural landscape as a national cultural asset in Korea with a history of more than several hundred years. Cultural heritage can retain their value when they are fully sustained their authenticity and management scheme. The Dangsan forests established in a large area have been designated as a natural monument by Cultural Heritage Administration. Small scale Dangsan forests, however, are not introduced to the public and on the verge of disappearance. Dangsan forests have a value as a core landscape element in rural landscapes of Korea. The two villages at Ijeon-ri, Cheongsong-gun have small Dangsan forests where Dangsan ritual is performed. At one of the villages, there is Jusanji Reservoir designated for Scenic Site # 105, from which the water is used for growing crops. In this study, the landscape characteristics of the Dangsan forests were investigated including rice paddy field, stream, and the Jusanji Reservoir. A conservation measure of rural landscape for sustainable management scheme was suggested by designating 'Conservation area of agricultural landscape ecology'. Dangsan forests, especially where they are in small scale like those of Ijeon-ri, tend to be neglected. The Dangsan forests ought to be recognized for their value and by providing a management scheme including neighborhood elements such as farm fields and streams they can be revitalized to be core areas for conservation of rural landscape.

Experimental Study on Aerodynamic Performance and Wake Characteristics of the Small Ducted Fan for VTOL UAV (수직 이착륙 무인기용 소형 덕티드팬의 공력성능 및 후류특성에 관한 실험적 연구)

  • Shin, Soo-Hee;Lee, Seung-Hun;Kim, Yang-Won;Cho, Tae-Hwan
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.50 no.1
    • /
    • pp.1-12
    • /
    • 2022
  • Wind tunnel test for a small scale electric ducted fan with a 104mm diameter was conducted to analyze the aerodynamic characteristics when it was used as a propulsion system of tilt-propeller UAV. Experimental conditions were derived from flight conditions of a sub-scaled OPPAV. Forces and moments of the ducted fan model were measured by a 6-axis balance and 3-dimensional wake vectors which could induce an aerodynamic influence in the vehicle were measured by 5-hole probes. Thrust and torque on hover and cruise conditions were measured and analyzed to drive out the operating conditions when it was applied in the sub-scaled OPPAV. On transition conditions, thrust keep its value with tilt angle variation below 40° and increase after that. But, sideforce increase constantly until 75°. The maximum axial velocity in the wake on hover and cruise conditions was around 60m/s and tangential velocity was around 12m/s. The position of the maximum axial velocity and vortex center move off the fan rotation center line as the tilt angle increases.

Scale Effects and Field Applications for Continuous Intrusion Miniature Cone Penetrometer (연속관입형 소형콘관입시험기에 대한 크기효과 및 현장적용)

  • Yoon, Sungsoo;Kim, Kyu-Sun;Lee, Jin Hyung;Shin, Dong-Hyun
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.33 no.6
    • /
    • pp.2359-2368
    • /
    • 2013
  • Cone penetration tests (CPTs) have been increasingly used for site characterizations. However, the site investigations using CPTs are often limited due to soil conditions depending on the cone size and capacity of the CPT system. The small sectional area of a miniature cone improves the applicability of the CPT system due to the increased capacity of the CPT system. A continuous intrusion system using a coiled rod allows fast and cost effective site investigation. In this study, the performance of the continuous intrusion miniature cone penetration test (CIMCPT) system has been evaluated by comparison tests with the standard CPT system at several construction sites in Korea. The results show that the CIMCPT system has a same performance with the CPT system and has advantages on the mobility and applicability. According to field verification tests for scale effect evaluation, the cone tip resistance evaluated by CIMCPT overestimates by 10% comparing to standard CPTs. A crawler mounted with the CIMCPT system has been implemented to improve accessibility to soft ground, and has shown improvement over the truck type CIMCPT system. Therefore, the improved CIMCPT system can be utilized as a cost effective and highly reliable soil investigation methodology to detect the depth of soft ground and to evaluate soil classification.