• 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).

• Journal of Korea Water Resources Association
• /
• v.55 no.12
• /
• pp.1125-1135
• /
• 2022

Damages by heavy snow does not occur very often, but when it does, it causes damage to a wide area. To mitigate snow damage, it is necessary to know, in advance, the depth of snow that causes damage in each region. However, snow depths are measured at observatory locations, and it is difficult to understand the spatial distribution of snow depth that causes damage in a region. To understand the spatial distribution of snow depth, the point measurements are interpolated. However, estimating spatial distribution of snow depth is not easy when the number of measured snow depth is small and topographical characteristics such as altitude are not similar. To overcome this limit, satellite images such as Synthetic Aperture Radar (SAR) can be analyzed using Differential Interferometric SAR (DInSAR) method. DInSAR uses two different SAR images measured at two different times, and is generally used to track minor changes in topography. In this study, the spatial distribution of snow depth was estimated by DInSAR analysis using dual polarimetric IW mode C-band SAR data of Sentinel-1B satellite operated by the European Space Agency (ESA). In addition, snow depth was estimated using geostationary satellite Chollian-2 (GK-2A) to compare with the snow depth from DInSAR method. As a result, the accuracy of snow cover estimation in terms with grids was about 0.92% for DInSAR and about 0.71% for GK-2A, indicating high applicability of DInSAR method. Although there were cases of overestimation of the snow depth, sufficient information was provided for estimating the spatial distribution of the snow depth. And this will be helpful in understanding regional damage-causing snow depth.

• Journal of Life Science
• /
• v.32 no.2
• /
• pp.135-141
• /
• 2022

Thymosin β-4 (TB4) is a small peptide composed of 43 amino acids. To obtain sufficient biologically active mouse TB4 economically, we cloned and overexpressed this gene in an Escherichia coli system. With the isopropyl β-D-1-thiogalactopyranoside induction of the E. coli transformant, TB4 fusion protein with intein- and chitin-binding domain was successfully expressed in the soluble fraction within the E. coli cell. The TB4-intein - chitin-binding domain fusion protein was purified from the soluble fraction of E. coli cell lysate. The affinity chromatography with chitin beads and dithiothreitol-mediated intein self-cleavage reaction releases the TB4 peptide into the stripping solution. Sodium dodecyl sulphate - polyacrylamide gel electrophoresis and Western blot analyses were used to confirm that the recombinant TB4 peptide was produced with the expected size of 5 kDa. We found that the recombinant TB4 stimulated cell migration in the transwell plate chamber assay. After 18 hr of the treatment of the recombinant TB4 with 1 ng/ml concentration, the migration of the HT1080 cell was increased by 20% compared with that of the chemically synthesized TB4. The recombinant TB4 was also observed to promote the healing of a wound area in C57BL/6 mice by as high as 35% compared with that of the chemically synthesized TB4. These results suggest that the recombinant TB4 has better biological activity for cell migration and wound healing than that of the chemically synthesized TB4 peptide.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.11 no.1
• /
• pp.79-94
• /
• 2009

The research project was conducted to develop a paper bagging machine for grape. This technology was aimed to highly reduce a labor for paper bagging in grape and bakery. In agriculture labor and farm population has rapidly decreased since 1980 in Korea so there was so limit in labor. In particular there is highly population in women and old age at rural area and thus labor cost is so high. Therefore a labor saving technology in agricultural sector might be needed to be replaced these old age with mechanical and labor saving tool in agriculture. The following was summarized of the research results for development of a paper bagging machine for grape. 1. Development of a new paper bagging machine for grape - This machine was designed by CATIA VI2/AUTO CAD2000 programme. - A paper bagging machine was mechanically binded a paper bag of grape which should be light and small size. This machine would be designed for women and old age with convenience during bagging work at the field site. - This machine was manufactured with total weight of less than 350g. - An overage bagging operation was more than 99% at the actual field process. - A paper bagging machine was designed with cartridge type which would be easily operated between rows and grape branches under field condition. - The type of cartridge pin was designed as a C-ring type with the length of 500mm which was good for bagging both grape and bakery. - In particular this machine was developed to easily operated among vines of the grape trees. 2. Field trials of a paper bagging machine in grape - There was high in grape quality as compared to the untreated control at the application of paper bagging machine. - The efficiency of paper bagging machine was 102% which was alternative tool for the conventional. - The roll pin of paper bagging machine was good with 5.3cm in terms of bagging precision. - There was no in grape quality between the paper bagging machine and the conventional method. - Disease infection and grape break was not in difference both treatments.

• (The) Research of the performance art and culture
• /
• no.42
• /
• pp.107-146
• /
• 2021

This article examined the current status of performance activities in the theaters in Ulsan during the Japanese colonial period, and examined the characteristics and social roles of performance culture at that time.,The cultural space during the Japanese colonial period can be divided into theater space and semi-theater space.,The theater spaces in Ulsan include Daejeonggwan, Sangbanggwan, and Ulsan Theater. The semi-theater spaces include Ulsan Youth Center, Ulsan Youth Alliance Hall, Barrack Youth Hall, Eonyang Youth Alliance Hall, Eonyang Christian Hall, Eonyang Christian Hall, Eonyang Inn, Eonyang Public Inn, Eonyang Public Normal School, Seosaeng School, Ulsan Public Aid Auditorium, Night school.,These spaces not only held events or performances for a specific purpose, but also played a role as public spaces producing local discourse. The theater was a complex cultural space where performances are performed along with movie performances, and artists and audiences meet.,Furthermore, the theater provided a special experience of producing and consuming various issues such as colonial modernization, modern city formation, and the emergence of new popular culture beyond the meaning of stage space.,The theaters in Ulsan also functioned as a space to represent the foreign culture acceptance, leisure activities, the performance and viewing of cultural contents, and the artistic skills of local artists in accordance with the purpose of establishing local theaters.,It was a base space for local discourse production and enjoyment activities by holding political rallies, meetings, lecture activities, and various conferences.,Political rallies were also concerts, enlightenment activities were also accompanied by film screenings, and music performances were associated with dance performances and charity gatherings.,In particular, Ulsan Theater, which is the first theater in Ulsan, and the role of the public hall, held a lecture, debate, and oratory for public enlightenment along with performances such as musical drama, children's song contest, fairy tale contest, small-sized play performance,, It was widely used as a large-scale rallying place, and served as a public hall, such as a place to visit outside theaters. Thus, the theater and semi-theater space in Ulsan during the Japanese colonial period improved the cultural level of the region, fulfilling the aesthetic needs of the local people and faithfully fulfilling the social role as a public sphere leading the public opinion and agenda.,And it was also positioned as an alternative public area of ​​modern society and also played a role as a public institution.

• Korean Journal of Heritage: History & Science
• /
• v.55 no.4
• /
• pp.56-70
• /
• 2022

Tombs No. 39 and No. 63 in Gyo-dong, Changnyeong, are unique in the Changnyeong area in that they do not have additional burials because they are hoenggu-style tombs with an entrance on the north side. This study tried to understand the nature and meaning of the two separate stone walls at the entrance of the tomb along with the burial process of the tomb. These two stone walls mark small tombs built independently within a large tomb, with stone wall No. 39 stone wall No. 3 (No.39-3) and No. 63 stone wall No. 3 (No. 63-3). Both units are located in the middle of the northern wall of the burial body part and share one wall with the burial body part wall stone. All animal fluids inside the stone wall were identified. In particular, it was estimated that at least three dogs were buried as a result of identification of animal fluids No. 63-3. Above all, these animals have their heads facing outward with their backs to the main occupants, and do not overlap in a limited space and are placed side by side. Changnyeong Gyo-dong No. 39-3 and 63-3 were created in the process of building the burial body, and although they are independent relics, they form a subordinate relationship in that they were built along the main burial within one tomb. In addition, it is coercive in that it is placed in an orderly manner according to a certain direction in a state that has not been dismantled after killing an animal. Therefore, It is understood to be the SHUNJANG of dogs. Studies on animal fluids excavated from tombs in the Three Kingdoms period are interpreted as animal stewardship, sacrificial collection, and animal sacrifice depending on their location, and this is known as a series of animal sacrifice rites, namely, animal stewardship and sacrifice. This recognition is based on material objectification of animals, such as food or sacrifices. However, Changnyeong Gyo-dong No. 39-3 and 63-3 are different in that they recognize animals as spiritual beings in the process of funeral rites and are closely related to the ideology that there is life after death. In addition, analysis of the location and directionality of the remains is also required from multiple angles. These two SHUNJANG correspond to the entrance to the tomb, and the location is the most open space at the entrance. The appearance of a dog looking outward, etc., can also be interpreted as the meaning of protecting the tombs and byeoksa. This appearance can be compared with the dog depicted in a mural in a Goguryeo tomb that reflects the ancient world's thought and stone figures excavated from the tomb of King Muryeong of Baekje, and it is also consistent with the meaning of the JINMYOSU protecting the ancient tombs. This suggests that a multifaceted study on animal fluid burial remains is needed in the future.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2021.06a
• /
• pp.6-7
• /
• 2021

Vegetation development in rivers is one of the important issues not only in academic fields such as geomorphology, ecology, hydraulics, etc., but also in river management practices. The problem of river vegetation is directly connected to the harmony of conflicting values of flood management and ecosystem conservation. In Korea, since the 2000s, the issue of river vegetation and land formation has been continuously raised under various conditions, such as the regulating rivers downstream of the dams, the small eutrophicated tributary rivers, and the floodplain sites for the four major river projects. In this background, this study proposes a method for classifying the distribution of vegetation in rivers based on remote sensing data, and presents the results of applying this to the Naeseong Stream. The Naeseong Stream is a representative example of the river landscape that has changed due to vegetation development from 2014 to the latest. The remote sensing data used in the study are images of Sentinel 1 and 2 satellites, which is operated by the European Aerospace Administration (ESA), and provided by Google Earth Engine. For the ground truth, manually classified dataset on the surface of the Naeseong Stream in 2016 were used, where the area is divided into eight types including water, sand and herbaceous and woody vegetation. The classification method used a random forest classification technique, one of the machine learning algorithms. 1,000 samples were extracted from 10 pre-selected polygon regions, each half of them were used as training and verification data. The accuracy based on the verification data was found to be 82~85%. The model established through training was also applied to images from 2016 to 2020, and the process of changes in vegetation zones according to the year was presented. The technical limitations and improvement measures of this paper were considered. By providing quantitative information of the vegetation distribution, this technique is expected to be useful in practical management of vegetation such as thinning and rejuvenation of river vegetation as well as technical fields such as flood level calculation and flow-vegetation coupled modeling in rivers.

• Journal of the Korean Society for information Management
• /
• v.39 no.4
• /
• pp.191-213
• /
• 2022

With a view to providing a high-quality policy information service beyond the existing national task service of the national policy information portal (POINT) of the National Library of Korea Sejong, it would be necessary to effectively provide the policy data needed for the implementation of the new national tasks. Accordingly, in this study, an attempt has been made to find a way to connect and develop the BRM-based national tasks and the policy information contents. Towards this end, first, the types of national tasks and the contents of each field and area of the government function's classification system were analyzed, with a focus placed on the 120 national tasks of the new administration. Furthermore, by comparing and analyzing the national tasks of the previous administration and the current information, the contents ought to be reflected for the development of contents related to the national tasks identified. Second, the method for linking and collecting the policy information was sought based on the analysis of the current status of policy information and the national information portal. As a result of the study, first, examining the 1st stage BRM of the national tasks, it turned out that there were 21 tasks for social welfare, 14 for unification and diplomacy, 17 for small and medium-sized businesses in industry and trade, 12 for general public administration, 8 for the economy, taxation and finance, 6 for culture, sports and tourism, science and technology, and education each, 5 for communication, public order and safety each, 4 for health, transportation and logistics, and environment each, 3 for agriculture and forestry, 2 for national defense and regional development each, and 1 for maritime and fisheries each, among others. As for the new administration, it is apparent that science technology and IT are important, and hence, it is necessary to consider such when developing the information services for the core national tasks. Second, to link the database with external organizations, it would be necessary to form a linked operation council, link and collect the information on the national tasks, and link and provide the national task-related information for the POINTs.

• Journal of Practical Engineering Education
• /
• v.15 no.1
• /
• pp.119-126
• /
• 2023

Today, in order to improve fuel efficiency and dynamic behavior of automobiles, an era of light weight and simplification of automobile parts is being formed. In order to simplify and design and manufacture the shape of the product, various components are integrated. For example, in order to commercialize three products into one product, product processing is occurring to a very narrow area. In the case of existing parts, precision die casting or casting production is used for processing convenience, and the multi-piece method requires a lot of processes and reduces the precision and strength of the parts. It is very advantageous to manufacture integrally to simplify the processing air and secure the strength of the parts, but if a deep and narrow pocket part needs to be processed, it cannot be processed with the equipment's own spindle. To solve a problem, research on cutting processing is being actively conducted, and multi-axis composite processing technology not only solves this problem. It has many advantages, such as being able to cut into composite shapes that have been difficult to flexibly cut through various processes with one machine tool so far. However, the reality is that expensive equipment increases manufacturing costs and lacks engineers who can operate the machine. In the five-axis cutting processing machine, when producing products with deep and narrow sections, the cycle time increases in product production due to the indirectness of tools, and many problems occur in processing. Therefore, dedicated machine tools and multi-axis composite machines should be used. Alternatively, an angle spindle may be used as a special tool capable of multi-axis composite machining of five or more axes in a three-axis machining center. Various and continuous studies are needed in areas such as processing vibration absorption, low heat generation and operational stability, excellent dimensional stability, and strength securing by using the angle spindle.

• Journal of Environmental Impact Assessment
• /
• v.32 no.6
• /
• pp.533-544
• /
• 2023

The Ministry of Agriculture, Food and Rural Affairs has been promoting policies to strengthen the functions of rural centers (culture, welfare, economy, education, etc.) and to ensure that services from the centers are delivered to and connected to hinterland villages. For this policy purpose, the rural center revitalization project and the basic living base creation project within the rural development projects are being promoted. However, in the process of carrying out the actual project, as the focus is on strengthening the functions of rural centers, service delivery and connection with hinterland villages are not being actively promoted. therefore, in this study, we analyze the projects previously carried out in Jeoksang-myeon, Muju-gun and the regional status, analyze the reasons why hinterland village services were not connected and activated, and propose a direction for the second phase of the basic living base creation project to be carried out in the future. As a result of analyzing the reasons for the failure of hinterland village services to be activated, problems such as disadvantages in accessing services due to dispersed residence in rural areas and limitations in topographical structure, and the lack of a service delivery system to develop demand in hinterland areas were found to be problems. Improvement measures were derived as follows. First, it is a stepping stone construction plan proposed to overcome topographical limitations. Establish a stepping base that will function as a service intermediate terminal to ensure efficient service delivery. Second, for a rational decision-making structure, we proposed a plan for deploying communication channels that could closely collect local opinions by operating various small-scale communities along with the efficient composition of a resident committee that includes residents of the central and hinterland villages and various classes. Third, it is a virtuous cycle of local manpower training plans that train local residents into professional instructors. We aim to complete a sustainable, resident-led service supply system by nurturing the most important service deliverers, that is, activists, in service delivery.