• Title/Summary/Keyword: Power system operation

Search Result 5,459, Processing Time 0.052 seconds

A Study on the Characteristics Measurement of Main Engine Exhaust Emission in Training Ship HANBADA (실습선 한바다호 주기관 배기가스 배출물질 특성 고찰에 관한 연구)

  • Choi, Jung-Sik;Lee, Sang-Deuk;Kim, Seong-Yun;Lee, Kyoung-Woo;Chun, Kang-Woo;Nam, Youn-Woo;Jung, Kyun-Sik;Park, Sang-Kyun;Choi, Jae-Hyuk
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.19 no.6
    • /
    • pp.658-665
    • /
    • 2013
  • In this study, we measured particulate matter(PM) which emerged as the hot issue from the International Maritime Organization(IMO) and the exhaust emission using HANBADA, the training ship of Korea Maritime University. In particular, the PM was obtained with TEM grid. PM structure was observed by electron microscopy. And exhaust gases such as NOx, $CO_2$, and CO were measured using the combustion gas analyzer(PG-250A, HORIBA). The results of this study are as follows. 1) When the ship departed from the port, the maximum difference in PM emissions were up to 30 % due to the Bunker Change. 2) Under the steady navigation, emission of PM was $1.34mg/m^3$ when Bunker-A is changing L.R.F.O(3 %). And, at the fixed L.R.F.O (3 %), emission of PM was $1.19mg/m^3$. When the main engine RPM increased up to 20 % with fixed L.R.F.O(3 %), emission of PM was $1.40mg/m^3$. When we changed to low quality oil(L.R.F.O(3 %)), CO concentration from main engine increased about 16 %. On the other hand, when the main engine RPM is rising up to 20 %, CO concentration is increased more than 152 percent. These results imply that the changes of RPM is a dominant factor in exhaust emission although fuel oil type is an important factor. 3) The diameter of PM obtained with TEM grid is about $4{\sim}10{\mu}m$ and its structure shows porous aggregate.

A Study on the Effects of the Characteristics of Franchise Business Members on Affiliate Outcomes (업종별 프랜차이즈 선택결정요인이 가맹점 성과의 만족도와 성공·실패에 미치는 영향연구)

  • Jang, Jae-Nam;Kang, Chang-Dong;Ahn, Sung-Sik
    • Journal of Distribution Science
    • /
    • v.9 no.2
    • /
    • pp.49-59
    • /
    • 2011
  • A franchise can be said to be the main method of distribution and marketing. It appears to be the future of the retail industry and is one of the world's fastest growing businesses sectors, as many policy reports and research results have acknowledged. Korea's franchise industry began in the 1970s, spread out into many areas (including food services, retail, and the service industry), and has grown by over 10% each year ever since. The industry's influence on the national economy becomes ever greater. Although the size of the franchise industry is expected to grow as it spreads and as the government expands its support, it has not yet attracted much academic interest. Research has so far been very fragmented. The main interest has been the relationship and conflicts between the head offices and the affiliates. No study has yet occurred on whether the concepts of satisfaction and intent to conclude a contract directly affect the success or failure of the affiliates. Few studies have empirically inquired into the demographic characteristics and abilities of the affiliates that significantly affect their results. Domestic franchise industries must prepare to leap from quantitative to qualitative growth. Most important is the need for affiliate headquarters and affiliates to build confidence between them. A friendly and reliable relationship between affiliate headquarters and affiliates will eliminate distrust from the franchise and maintain a healthy franchise system. This study suggests that current and prospective heads of affiliation should concentrate not on attracting affiliates but on investment and techniques of affiliate support. They should work on the reinforcement of brand power, the appropriate affiliate business environment, systematic education/training, taking burdens off the affiliate business persons, consolidating the relationship with the affiliate business persons, marketing mix factors (e.g. products, price conditions, logistics and shipping services, promotion, supervising and supervisor, operation procedures/processes, and material evidence); these all greatly affect the success or failure of the affiliate business. Supporting the affiliates is an important factor that enhances their results and satisfaction and consequently increases the positive recommendations to others and the ratio of recurrent conclusions of contracts, which ultimately generate the growth of the franchises. In addition, it is suggested that prospective franchise founders should make every effort to choose a good head office since the characteristics of the head office greatly influence the success of the affiliates. This study is significant in that it grasps the characteristics of the head office of affiliation and of the affiliates that influence affiliate results in ways not yet academically attempted.

  • PDF

A Study on the establishment of IoT management process in terms of business according to Paradigm Shift (패러다임 전환에 의한 기업 측면의 IoT 경영 프로세스 구축방안 연구)

  • Jeong, Min-Eui;Yu, Song-Jin
    • Journal of Intelligence and Information Systems
    • /
    • v.21 no.2
    • /
    • pp.151-171
    • /
    • 2015
  • This study examined the concepts of the Internet of Things(IoT), the major issue and IoT trend in the domestic and international market. also reviewed the advent of IoT era which caused a 'Paradigm Shift'. This study proposed a solution for the appropriate corresponding strategy in terms of Enterprise. Global competition began in the IoT market. So, Businesses to be competitive and responsive, the government's efforts, as well as the efforts of companies themselves is needed. In particular, in order to cope with the dynamic environment appropriately, faster and more efficient strategy is required. In other words, proposed a management strategy that can respond the IoT competitive era on tipping point through the vision of paradigm shift. We forecasted and proposed the emergence of paradigm shift through a comparative analysis of past management paradigm and IoT management paradigm as follow; I) Knowledge & learning oriented management, II) Technology & innovation oriented management, III) Demand driven management, IV) Global collaboration management. The Knowledge & learning oriented management paradigm is expected to be a new management paradigm due to the development of IT technology development and information processing technology. In addition to the rapid development such as IT infrastructure and processing of data, storage, knowledge sharing and learning has become more important. Currently Hardware-oriented management paradigm will be changed to the software-oriented paradigm. In particular, the software and platform market is a key component of the IoT ecosystem, has been estimated to be led by Technology & innovation oriented management. In 2011, Gartner announced the concept of "Demand-Driven Value Networks(DDVN)", DDVN emphasizes value of the whole of the network. Therefore, Demand driven management paradigm is creating demand for advanced process, not the process corresponding to the demand simply. Global collaboration management paradigm create the value creation through the fusion between technology, between countries, between industries. In particular, cooperation between enterprises that has financial resources and brand power and venture companies with creative ideas and technical will generate positive synergies. Through this, The large enterprises and small companies that can be win-win environment would be built. Cope with the a paradigm shift and to establish a management strategy of Enterprise process, this study utilized the 'RTE cyclone model' which proposed by Gartner. RTE concept consists of three stages, Lead, Operate, Manage. The Lead stage is utilizing capital to strengthen the business competitiveness. This stages has the goal of linking to external stimuli strategy development, also Execute the business strategy of the company for capital and investment activities and environmental changes. Manege stage is to respond appropriately to threats and internalize the goals of the enterprise. Operate stage proceeds to action for increasing the efficiency of the services across the enterprise, also achieve the integration and simplification of the process, with real-time data capture. RTE(Real Time Enterprise) concept has the value for practical use with the management strategy. Appropriately applied in this study, we propose a 'IoT-RTE Cyclone model' which emphasizes the agility of the enterprise. In addition, based on the real-time monitoring, analysis, act through IT and IoT technology. 'IoT-RTE Cyclone model' that could integrate the business processes of the enterprise each sector and support the overall service. therefore the model be used as an effective response strategy for Enterprise. In particular, IoT-RTE Cyclone Model is to respond to external events, waste elements are removed according to the process is repeated. Therefore, it is possible to model the operation of the process more efficient and agile. This IoT-RTE Cyclone Model can be used as an effective response strategy of the enterprise in terms of IoT era of rapidly changing because it supports the overall service of the enterprise. When this model leverages a collaborative system among enterprises it expects breakthrough cost savings through competitiveness, global lead time, minimizing duplication.

Development of a Finger Tactile Stimulator Based on E-Prime Software (E-Prime에 기반한 손가락 촉각 자극기의 개발)

  • Kim, Hyung-Sik;Min, Yoon-Ki;Kim, Bo-Seong;Min, Byung-Chan;Yang, Jae-Woong;Lee, Su-Jeong;Choi, Mi-Hyun;Yi, Jeong-Han;Tack, Gye-Rae;Lee, Bong-Soo;Jun, Jae-Hoon;Chung, Soon-Cheol
    • Science of Emotion and Sensibility
    • /
    • v.13 no.4
    • /
    • pp.703-710
    • /
    • 2010
  • In this study, a tactile stimulator was developed to resolve some problems from the previous version of the system such as system configuration, inappropriate stimulation control and additional problems. The developed tactile stimulator consists of control unit, drive unit and vibrator unit. The control unit was controlled by E-Prime software to generate appropriate vibration pulses. The drive unit supplies enough energy to the vibrator to generate effective stimulation pulses. The vibrator unit consists of small coin type vibrator and velcro, and was made to be attached at the hand easily. The developed tactile stimulator was designed by small-size, light-weight, low-power, simple-fabrication, max 35 channels and little delay time from instruction signal of E-Prime software to vibrator. The duration and magnitude of stimulation was controlled by 10 grades and the problems concerning stimulation control were compensated by wideband frequency ranges. Additionally, the electrical safety was ensured by low voltage operation. Vibrator was made to be attached on finger as well as on any part of the subject. Since this tactile stimulator is developed based on E-Prime software which is widely used in cognitive science, it is believed that this stimulator be suitable for the wide application of cognitive science study.

  • PDF

Sterilization of Neurospora Crassa by Noncontacted Low Temperature Atmospheric Pressure Surface Discharged Plasma with Dielectric Barrier Structure (유전체장벽 방전구조의 비접촉식 저온 대기압 면방전 플라즈마를 이용한 빵곰팡이의 살균효과)

  • Ryu, Young Hyo;Uhm, Han Sup;Park, Gyung Soon;Choi, Eun Ha
    • Journal of the Korean Vacuum Society
    • /
    • v.22 no.2
    • /
    • pp.55-65
    • /
    • 2013
  • Sterilization of Neurospora crassa has been investigated in this research by using a surface air plasma with dielectric barrier discharged (DBD) structure under atmospheric pressure. The sinusoidal alternating current has been used in this experiment with discharge voltage of 1.4~2.3 kV. The phase difference between the voltage and current signals are found to be almost 80 degree due to the capacitive property of dielectric barrier. Temperature on the biomaterials has been minimized by radiating the heat with the air cooling system. It is noted that the substrate temperature remains under 37 degree for plasma exposure time of 10 minutes with operation of cooler system. It is found that the ozone, $O_3$, has been measured to be about 25~30 ppm within 1 cm region and to be about 5 ppm at the 150 cm downstream region away from the suface plasma. It is also noted that the nitric oxide, NO, and nitric dioxide, $NO_2$, are not nearly detected. Germination rate and mitochodrial activity of Neurospora crassa immersed in the deionized water have been found to be drastically decreased as the plasma treatment time and its electrical power are increased in this experiment. Here, the mitochondrial activity has been analyzed by MTT (3-(4,5-dimethy lthiazol-2yl)-2,5-diphenyl-2H-tetrazolium bromide) assay. However, sterilization of Neurospora crassa immersed in the Vogel's minimal media has been found to be low by plasma treatment, which is caused by surrounding background solution. This research shows the sterilization possibility of Neurospora crassa by using the noncontated surface DBD plasma, which is different from the plasma jet. This is mainly attibuted to the reactive species generated by the surface plasma, since they play a major role for inhibition of micobes such as Neurospora crassa.

A STUDY ON THE JUJEON OF AUTOMATIC CLEPSYDRA IN EARLY JOSEON DYNASTY (조선 전기 자동물시계의 주전(籌箭) 연구)

  • YUN, YONG-HYUN;KIM, SANG HYUK;MIHN, BYEONG-HEE;OH, KYONG TAEK
    • Publications of The Korean Astronomical Society
    • /
    • v.36 no.3
    • /
    • pp.65-78
    • /
    • 2021
  • Jagyeokru, an automatic striking water clock described in the Sejong Sillok (Veritable Records of King Sejong) is essentially composed of a water quantity control device and a time-signal device, with the former controlling the amount or the flow rate of water and the latter automatically informing the time based on the former. What connects these two parts is a signal generating device or a power transmission device called the 'Jujeon' system, which includes a copper rod on the float and ball-racked scheduled plates. The copper products excavated under Gongpyeong-dong in Seoul include a lot of broken plate pieces and cylinder-like devices. If some plate pieces are put together, a large square plate with circular holes located in a zigzag can be completed, and at the upper right of it is carved 'the first scheduled plate (一箭).' Cylinder-like devices generally 3.8 cm in diameter are able to release a ball, and have a ginkgo leaf-like screen fixed on the inner axis and a bird-shaped hook of which the leg fixes another axis and the beak attaches to the leaf side. The lateral view of this cylinder-like device appears like a trapezoid and mounts an iron ball. The function of releasing a ball agrees with the description of Borugak Pavilion, where Jagyeokru was installed, written by Kim Don (1385 ~ 1440). The other accounts of Borugak Pavilion's and Heumgyeonggak Pavilion's water clocks describe these copper plates and ball releasing devices as the 'Jujeon' system. According to the description of Borugak Pavilion, a square wooden column has copper plates on the left and right sides the same height as the column, and the left copper plate has 12 drilled holes to keep the time of a 12 double-hours. Meanwhile, the right plate has 25 holes which represent seasonal night 5-hours (Kyeong) and their 5-subhours (Jeom), not 12 hours. There are 11 scheduled plates for seasonal night 5-hours made with copper, which are made to be attached or detached as the season. In accordance with Nujutongui (manual for the operation of the yardstick for the clepsydra), the first scheduled plate for the night is used from the winter solstice (冬至) to 2 days after Daehan (大寒), and from 4 days before Soseol (小雪) to a day before the winter solstice. Besides the first scheduled plate, we confirm discovering a third scheduled plate and a sixth scheduled plate among the excavated copper materials based on the spacing between holes. On the other hand, the width of the scheduled plate is different for these artifacts, measured as 144 mm compared to the description of the Borugak Pavilion, which is recorded as 51 mm. From this perspective, they may be the scheduled plates for the Heumgyeonggak Ongru made in 1438 (or 1554) or for the new Fortress Pavilion installed in Changdeokgung palace completed in 1536 (the 31st year of the reign of King Jungjong) in the early Joseon dynasty. This study presents the concept of the scheduled plates described in the literature, including their new operating mechanism. In addition, a detailed model of 11 scheduled plates is designed from the records and on the excavated relics. It is expected that this study will aid in efforts to restore and reconstruct the automatic water clocks of the early Joseon dynasty.

Investigation on Diesel Injection Characteristics of Natural Gas-Diesel Dual Fuel Engine for Stable Combustion and Efficiency Improvement Under 50% Load Condition (천연가스-디젤 혼소 엔진의 50% 부하 조건에서 제동효율 및 연소안정성 개선을 위한 디젤 분무 특성 평가)

  • Oh, Sechul;Oh, Junho;Jang, Hyungjun;Lee, Jeongwoo;Lee, Seokhwan;Lee, Sunyoup;Kim, Changgi
    • Journal of the Korean Institute of Gas
    • /
    • v.26 no.3
    • /
    • pp.45-53
    • /
    • 2022
  • In order to improve the emission of diesel engines, natural gas-diesel dual fuel combustion compression ignition engines are in the spotlight. In particular, a reactivity controlled compression ignition (RCCI) combustion strategy is investigated comprehensively due to its possibility to improve both efficiency and emissions. With advanced diesel direct injection timing earlier than TDC, it achieves spontaneous reaction with overall lean mixture from a homogeneous mixture in the entire cylinder area, reducing nitrogen oxides (NOx) and particulate matter (PM) and improving braking heat efficiency at the same time. However, there is a disadvantage in that the amount of incomplete combustion increases in a low load region with a relatively small amount of fuel-air. To solve this, sensitive control according to the diesel injection timing and fuel ratio is required. In this study, experiments were conducted to improve efficiency and exhaust emissions of the natural gas-diesel dual fuel engine at low load, and evaluate combustion stability according to the diesel injection timing at the operation point for power generation. A 6 L-class commercial diesel engine was used for the experiment which was conducted under a 50% load range (~50 kW) at 1,800 rpm. Two injectors with different spray patterns were applied to the experiment, and the fraction of natural gas and diesel injection timing were selected as main parameters. Based on the experimental results, it was confirmed that the brake thermal efficiency increased by up to 1.3%p in the modified injector with the narrow-angle injection added. In addition, the spray pattern of the modified injector was suitable for premixed combustion, increasing operable range in consideration of combustion instability, torque reduction, and emissions level under Tier-V level (0.4 g/kWh for NOx).

Application of Seawater Plant Technology for supporting the Achievement of SDGs in Tarawa, Kiribati (키리바시 타라와의 지속가능발전목표 달성 지원을 위한 해수플랜트 기술 활용)

  • Choi, Mi-Yeon;Ji, Ho;Lee, Ho-Saeng;Moon, Deok-Soo;Kim, Hyeon-Ju
    • Journal of Appropriate Technology
    • /
    • v.7 no.2
    • /
    • pp.136-143
    • /
    • 2021
  • Pacific island countries, including Kiribati, are suffering from a shortage of essential resources as well as a reduction in their living space due to sea level rise and coastal erosion from climate change, groundwater pollution and vegetation changes. Global activities to solve these problems are being progressed by the UN's efforts to implement SDGs. Pacific island countries can adapt to climate change by using abundant marine resources. In other words, seawater plants can assist in achieving SDGs #2, #6 and #7 based on SDGs #14 in these Pacific island countries. Under the auspice of Korea International Cooperation Agency (KOICA), Korea Research Institute of Ships and Ocean Engineering (KRISO) established the Sustainable Seawater Utilization Academy (SSUA) in 2016, and its 30 graduates formed the SSUA Kiribati Association in 2017. The Ministry of Oceans and Fisheries (MOF) of the Republic of Korea awarded ODA fund to the Association. By taking advantage of seawater resource and related plants, it was able to provide drinking water and vegetables to the local community from 2018 to 2020. Among the various fields of education and practice provided by SSUA, the Association hope to realize hydroponic cultivation and seawater desalination as a self-support project through a pilot project. To this end, more than 140 households are benefiting from 3-stage hydroponics, and a seawater desalination system in connection with solar power generation was installed for operation. The Association grows and supplies vegetable seedlings from the provided seedling cultivation equipment, and is preparing to convert to self-support business from next year. The satisfaction survey shows that Tarawa residents have a high degree of satisfaction with the technical support and its benefits. In the future, it is hoped that SSUA and regional associations will be distributed to neighboring island countries to support their SDGs implementations.

Research for Space Activities of Korea Air Force - Political and Legal Perspective (우리나라 공군의 우주력 건설을 위한 정책적.법적고찰)

  • Shin, Sung-Hwan
    • The Korean Journal of Air & Space Law and Policy
    • /
    • v.18
    • /
    • pp.135-183
    • /
    • 2003
  • Aerospace force is a determining factor in a modem war. The combat field is expanding to space. Thus, the legitimacy of establishing aerospace force is no longer an debating issue, but "how should we establish aerospace force" has become an issue to the military. The standard limiting on the military use of space should be non-aggressive use as asserted by the U.S., rather than non-military use as asserted by the former Soviet Union. The former Soviet Union's argument is not even strongly supported by the current Russia government, and realistically is hard to be applied. Thus, the multi-purpose satellite used for military surveillance or a commercial satellite employed for military communication are allowed under the U.S. principle of peaceful use of space. In this regard, Air Force may be free to develop a military surveillance satellite and a communication satellite with civilian research institute. Although MTCR, entered into with the U.S., restricts the development of space-launching vehicle for the export purpose, the development of space-launching vehicle by the Korea Air Force or Korea Aerospace Research Institute is beyond the scope of application of MTCR, and Air Force may just operate a satellite in the orbit for the military purpose. The primary task for multi-purpose satellite is a remote sensing; SAR sensor with high resolution is mainly employed for military use. Therefore, a system that enables Air Force, the Korea Aerospace Research Institute, and Agency for Defense Development to conduct joint-research and development should be instituted. U.S. Air Force has dismantled its own space-launching vehicle step by step, and, instead, has increased using private space launching vehicle. In addition, Military communication has been operated separately from civil communication services or broadcasting services due to the special circumstances unique to the military setting. However, joint-operation of communication facility by the military and civil users is preferred because this reduces financial burden resulting from separate operation of military satellite. During the Gulf War, U.S. armed forces employed commercial satellites for its military communication. Korea's participation in space technology research is a little bit behind in time, considering its economic scale. In terms of budget, Korea is to spend 5 trillion won for 15 years for the space activities. However, Japan has 2 trillion won annul budget for the same activities. Because the development of space industry during initial fostering period does not apply to profit-making business, government supports are inevitable. All space development programs of other foreign countries are entirely supported by each government, and, only recently, private industry started participating in limited area such as a communication satellite and broadcasting satellite, Particularly, Korea's space industry is in an infant stage, which largely demands government supports. Government support should be in the form of investment or financial contribution, rather than in the form of loan or borrowing. Compared to other advanced countries in space industry, Korea needs more budget and professional research staff. Naturally, for the efficient and systemic space development and for the prevention of overlapping and distraction of power, it is necessary to enact space-related statutes, which would provide dear vision for the Korea space development. Furthermore, the fact that a variety of departments are running their own space development program requires a centralized and single space-industry development system. Prior to discussing how to coordinate or integrate space programs between Agency for Defense Development and the Korea Aerospace Research Institute, it is a prerequisite to establish, namely, "Space Operations Center"in the Air Force, which would determine policy and strategy in operating space forces. For the establishment of "Space Operations Center," policy determinations by the Ministry of National Defense and the Joint Chief of Staff are required. Especially, space surveillance system through using a military surveillance satellite and communication satellite, which would lay foundation for independent defense, shall be established with reference to Japan's space force plan. In order to resolve issues related to MTCR, Air Force would use space-launching vehicle of the Korea Aerospace Research Institute. Moreover, defense budge should be appropriated for using multi-purpose satellite and communication satellite. The Ministry of National Defense needs to appropriate 2.5 trillion won budget for space operations, which amounts to Japan's surveillance satellite operating budges.

  • PDF

A Study on the Validity of Rural Type Low Carbon Green Village Through Case Analysis (사례분석을 통한 농촌형 저탄소 녹색마을 타당성 검토)

  • Do, In-Hwan;Hwang, Eun-Jin;Hong, Soo-Youl;Phae, Chae-Gun
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.33 no.12
    • /
    • pp.913-921
    • /
    • 2011
  • This study examined the overall feasibility of low carbon green village formed in rural area. The check method is analyzing its environmental and economic feasibility and energy self-reliance. The biomass of the villages was set as 28 ton/day of livestock feces and 2 ton/day of cut fruit tree branches which make up the total of 30 ton/day. The facility consisted of a bio gasfication facility using wet (livestock feces) biomass and combined heat power generator, composting facility and wood boiler using dry (cut fruit tree branches) biomass. When operating the system, 540,540 kWh/yr of electricity and 1,762 Gcal/yr of heat energy was produced. The region's electricity energy and heat energy self-reliance rate will be 100%. The economic feasibility was found as a loss of 140 million won where the facility installation cost is 5.04 billion won, operation cost is 485.09 million won and profit is 337.12 million won. There will be a loss of about 2.2 billion won in 15 years but in the environmental analysis, it was found that crude replacement effect is about 178 million won, greenhouse gas reduction effect is about 92 million won making up the total environmental benefit of 270 million won. This means, there will be a yearly profit of about 130 million won. In terms of its environmental and economic feasibility and energy self-reliance, this project seemed to be a feasible project in overall even if it manages to get help from the government or local government.