• Journal of Biosystems Engineering
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• v.12 no.1
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• pp.53-62
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• 1987

Automation of agricultural machinery is a high technology needed to increase work capacity and accuracy, to save agricultural resources and energy, to solve labor shortage, and to improve operator's comfort and safety. With the rapid development of electronic industry, automation of agricultural machinery will be progressed fast, and eventually will lead to no-operator machines or agricultural robots. Automation should be promoted step by step without increasing the cost of farming, excluding rural labor forces, decreasing labor volition, and losing human nature. In order to achieve rational automation of agricultural machinery, it is necessary to investigate the characteristics of soils and crops, to develop sensors, controllers and robots with artificial intelligence. It is recommended that the present trends to directly automatize the individual machinery be changed to the development of a harmonious automation system for overall farming.

• Journal of Korean Society of Forest Science
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• v.108 no.4
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• pp.645-654
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• 2019

The purpose of this study was to analyze the current status of and necessity for forest education in Korea in order to promote educational programs on the topic among different age groups. A survey conducted among 1,542 adults nationwide indicated that different age groups had variable degrees of awareness and experience of forest education programs. Specifically, older people responded more positively in terms of awareness, experience, and willingness to engage with forest education programs, and engaging in individual holistic development. In addition, participant companion types and motivation for participating in forest education programs were different among age groups. Regarding motivation for participating in forest education programs, all groups answered, "to enjoy the forest landscape," "to experience new things," and "to refresh themselves." In particular, individuals in their 30s had a desire to learn, while those in their 50s had a desire for a healthy lifestyle. Additionally, people in their 40s showed the highest participation rate in forest education programs, alongside their children and family members. In terms of operating period, older individuals preferred long-term operating programs. Accessibility was the most important factor for all age groups when selecting forest education programs. We hope that this study will be useful for the development and promotion of forest education programs for all age groups.

• The KIPS Transactions:PartC
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• v.9C no.1
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• pp.107-114
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• 2002

In these days, rapid advances of the computer system and the high speed network have made the multimedia services popularized among various applications and services in the internet. Internet live broadcasting, a part of multimedia services, makes it possible to provide not only existing broadcasting services including audio and video but also interactive communications which also expand application scopes by freeing from both temporal and spatial limitation. In the Paper, an interned Personal-live broadcasting server system is developed by allowing individual users to actively create or join live-broadcasting services with such basic multimedia devices as a PC camera and a sound card. As the number of broadcasters and participants increases, concurrent multiple channels are established and groups are to be expanded. The system should also guarantee High Availability (HA) for continuous services even in the presence of partial failure of the cluster. Furthermore, a transmission mode switching is supported to consider network environments in the user system.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.62-62
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• 2000

비접촉식 온도센서는 물체에서 방출하는 적외선 등의 복사신호를 열에너지로 전환하고 이를 다시 전기신호로 2차 에너지 변환하여 온도를 감지하는 센서로 인체 검지를 응용한 다양한 상품 및 교통, 방재, 빌딩 시스템 등의 분야에 널리 응용되고 있다. 비접촉식 적외선 센서는 열에너지를 전기에너지로 변환하는 방법에 따라 양자형과 열형으로 구분되며, 이중 양자형은 광전도나 광기전력 효과 등을 이용하여 감도 및 응답성이 우수하다는 장점을 지니고 있지만, 소자부를 80K 이하 온도로 유지시키는 냉각을 필요로 하므로 대형 제작이 불가피하고 그 용도가 제한적이다. 열형은 냉각이 필요 없고 소형으로 제작가능한 장점을 지니고 있어 써모 파일이나 초전체를 이용한 번용 센서가 보급되고 있다. 그러나 써모파일의 경우 출력되는 전기 신호가 미약하여 감도 및 응답성을 향상하기 위해 구조가 복잡하고, 특히 모터초퍼나 저항을 전압으로 변환시키는 전력기 등이 필요로 하는 단점을 지니고 있다. 따라서 이러한 문제점을 보완하기 위해 열전재료 박막을 이용한 적외선 센서를 개발하려는 노력이 진행중에 있다. 열전박막을 이용한 적외선 센서는 열전재료의 Seebeck 현상을 이용하여 열에너지에서 전기에너지의 변환이 자가발전으로 이루어져 offset과 외부 바이어스를 필요로 하지 않는다. 또한 작은 온도 변화에도 그 감도와 응답성이 높고, 출력신호가 커서 증폭기 등이 불필요한 장점을 지니고 있다. 특히 초전형 센서가 상온에서도 기판에 대한 열 확산을 제어해야 하는 문제점을 갖는 반면, 열전박막형 적외선 센서는 고온에서도 안정된 출력 신호를 얻을 수 있어 그 활용 온도 범위가 크게 확대될 것으로 기대된다. 본 실험에서는 우수한 열전특성을 갖는 (Bi1-xSbx)2Te3 박막을 얻기 위해 열팽창계수가 작고 알칼리 원소가 0.3% 이하로 포함되어 있는 corning glass(# 7059)를 기판으로 사용하였다. 또한 최적의 열전특성을 나타내는 조성을 실험적으로 구하기 위해 (Bi0.2Sbx)2Te3 조성의 합금 타？ 위에 Bi2Te3 및 Sb2Te3 chip을 올려놓고 그 면적을 변화시켜 다양한 조성의 열전박막을 증착하였다. 열전박막의 증착시 산화와 오염에 의한 열전특성 변화를 최소화하기 위해 초기진공도를 1$\times$10-6 Torr로 하였으며, Ar 가스를 흘려주어 2$\times$102 Torr 의 증착진공도를 유지하였다. 열전박막을 증착하기 전에 기판을 10분간 200W의 출력으로 RF 처리하였으며, 30$0^{\circ}C$에서 33 /sec의 속도로 (Bi1-xSbx)2Te3 박막을 증착하였다. 이와 같이 제조된 (Bi1-xSbx)2Te3 박막의 미세구조를 SEM으로 관찰하고 EDS로 조성을 분석하였으며, XRD를 이용하여 결정성을 관찰하였다. 또한 (Bi1-xSbx)2Te3 박막의 Seebeeck 계수 및 전기비저항을 측정하고 증착된 박막조성, 결정상, 미세구조와 열전특성간의 상관관계를 고찰하였다.

• Land and Housing Review
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• v.2 no.4
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• pp.429-437
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• 2011

The purpose of this research is to seek the suggestions applicable to Korean green-growth(development) policy and the realization of low carbon society by looking around the promotion policy and the process, the promotion system, main environmental policy in each city about the business for environmental model city in Japan which has been promoted in a city in order to realize low-carbon society. Japan had selected 13 local governments as an environmental model city as a part of a policy to build low-carbon society in 2008~2009, and Japan has formed information sharing between cities and provinces, the spread of information sharing and the free competition among local governments for an environmental model city through Zero Carbon City Promotion Council consisting of local governments and specialists. When examining these cases in Japan, the green-growth policy promoting currently in Korea needs to be converted from the central government-dominated policy to the local government-dominated policy and Koreaneeds to make more effort to develop software programs in order to realize green-growth social system.

• Journal of Energy Engineering
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• v.28 no.3
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• pp.42-54
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• 2019

The solar and wind power is spreading as a means to $CO_2$ reduction, but it has the characteristics of the volatility depending on the weather changes. This article aims to estimate the additional integration costs in Korea electric system in response to such volatility of increasing solar and wind power generation, using Korea electric power trading analyzer(KEPTA). The analysis utilizes the statistics of "8th Basic Plan for Long-term Electricity Supply and Demand" and "Renewable Energy Plan 3020". As the results, integration costs will be estimated 13.94Won/kWh~32.55Won/kWh, consisting of 8.94Won/kWh as back-up costs, 1.03Won/kWh~4.45Won/kWh as balancing costs, and 3.97Won/kWh~19.16Won/kWh as grid-costs. These results suggest that when the integration costs are secured, Korea electric system will be expected in the stable situation. This article leaves the further studies with taking the technological development of solar and wind power generation, the introduction of energy storage system, and wholesale price of electricity into consideration.

• Journal of the Korean Institute of Gas
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• v.25 no.4
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• pp.27-35
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• 2021

Recently, as a solution to the sharp drop in "power reserve ratio", it is being converted to a microgrid that enables bi-directional transmission and distribution. A microgrid is composed of a small-scale distributed power supply and a load. As a representative technology of distributed power generation, there is a Micro Combined Heat and Power system applied to homes and buildings. In this study, a safety standard was developed by dividing the power generation system, cooling system, lubrication system, and exhaust system to derive safety standards for a small gas engine power generation system with a gas consumption less than 232.6kW (200,000 kcal/h). In the case of the power generation system, a filter was installed and the system was stopped by detecting gas leakage and abnormalities in engine speed or output and the cooling system is stipulated to stop the system in case of insufficient cooling water or overheating. The lubrication system monitors the pressure and temperature of the lubricating oil and stops the system when an abnormality occurs, and the exhaust gas emission concentration regulation value was specified in accordance with domestic and foreign standards. Through the results of this study, it is judged that the safety of the gas engine power generation system can be improved and it can contribute to the commercialization of products.

• Journal of Korean Society of Archives and Records Management
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• v.19 no.3
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• pp.271-292
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• 2019

Recently, the central administrative agency changed its business management system to cloud-based On-nara 2.0. To transfer and manage the records of the cloud business management system, the National Archives Service has developed and distributed a cloud-based records management system. It serves as an opportunity to maximize the benefits of cloud computing and redesign the records management to be more effective and efficient. The process and method of electronic record management can be transformed through digital technologies. First, we can change the transfer method for electronic records. When the business and the records management systems share the same cloud storage, it is possible to transfer the content files between the two systems without moving the contents files physically, thus copying only the metadata and reducing the cost and the risk of integrity damage. Second, the strategy for allocating storage space for contents can be conceived. Assuming that the cloud storage is shared by the business and the record management systems, it is advantageous to distinguish the storage location based on the retention period of the content files. Third, systems that access content files, such as records creation, records management, and information disclosure systems, can share the cloud storage and minimize the duplication of content files.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.626-631
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• 2019

The policy-making and technological development for the supply expansion of eco-friendly automobiles has been continuing, but the internal combustion engines still accounts for about 95%. Also, in order to meet the stricter emission regulations of internal combustion engines based on fossil fuels, the proportion of after-treatments for vehicles and (ocean going) vessels is gradually increasing. This study is a basic study for the post-Euro-VI exhaust response of CNG buses, and it is to investigate the basic characteristics according to Pd substitution transition metal effect, catalyst volume effect and space velocity. A catalysts was prepared and tested using a model gas reactor. The NGOC catalyst with 3Pd exhibited the highest catalytic activity with 22% at $300^{\circ}C$, 48% at $350^{\circ}C$ and about 75% at $500^{\circ}C$. 3Co NGOC containing 3wt% of transition metal was excellent in oxidation ability, and it was small in size of 2nm, and the degree of catalyst dispersion was improved and de-NO/CO conversion was high. The volume of the NGOC-LNT-SCR catalyst system was optimal in the combination of 1.5+0.5+0.5 with a total score of 165, considering $de-CH_4/NOx$ performance and catalyst cost. For SV $14,000h^{-1}$, the $CH_4$ reduction performance was the highest at about 20%, while the SV $56,000h^{-1}$ was the lowest at about 5%. If the space velocity is small, the flow velocity decreases and the time remaining in the catalyst volume become long, so that the harmful gas was reduced.

• KEPCO Journal on Electric Power and Energy
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• v.5 no.1
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• pp.25-32
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• 2019

K-BEMS System was introduced to reduce peak load and to save total energy of the 200 buildings that KEPCO headquarter and branch offices use. And K-BEMS system is composed of PV, battery, and hybrid PCS. KEPCO research institute has carried out this K-BEMS research project for 3 years since January 2016. In this paper, the results of the project are shown. 9 modes of test results of K-BEMS system and are operational problems were analyzed. And measures to cure the trouble are also suggested. Batteries are operated more than 20% of SOC, and less than 20% of SOC battery protection switches are automatically shutting down the system and the system no longer respond to EMS, ending the supply of PV, and so therefore to continue the PV power supply it was turn out to be necessary that the EMS should automatically change its policy to change PV only supply mode automatically when the Battery Switch automatically operated. To operate the system continuously and automatically, it is necessary to modify the minimum operational SOC value, and in addition to that the EMS computer must remember the last shut-down SOC and Voltage which interrupted the system and add some margin to reflect the measurement error in the system.