• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.1
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• pp.15-20
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• 2008

Contaminated sediments are the actual cause for deterioration of coastal-ecosystem. So the developed countries have been in the process of making an effort to develop new techniques for monitoring and solving this problem since 1960. In this research, suction type pump dredging system of pilot size for collecting the filth from the seabed has been designed and manufactured that can prevent or minimize the secondary pollution by filth diffusion. For the practical use, the application possibility of the developed system has been checked through a system performance test. And, the evaluation of system performance according to the underwater body type has been carried out for system optimization by using CFD. The performance tests for checking the efficiency of sediment collecting system are done under two conditions i.e. when the system is non-operational and when the system is self-propelled. The results of this research showed the possibility of the development of dredging system to remove just the upper parts of filth from seabed.

• Journal of Information Technology and Architecture
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• v.9 no.2
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• pp.143-154
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• 2012

With the realization of the importance of the NWI, iterated by the Cheonan Ship sink and the YP-Do shelling, this thesis separates the NWI from the peninsula, regarding it separate from the Korea Theater of Operations, and suggests the method to establish NCOE with consideration to the characteristics of separated theater as well as the current situation. Although the NWI holds strategic value, systematical NCOE of surveillance and reconnaissance system, command and control system, and precision strike system is not yet established. Pertaining to this issue, Architecting was utilized to identify improvement measures and of the identified improvement measures, improvement on the "strike on nK hardened artillery sites with K-9 Self-Propelled Artillery in correlations with theater ISR" shows greatly improved strike effects when conducting simulations based on the Operation-Plan Analysis Model. Such a method of NCOE establishment will serve as a standard model for military force building and operation execution system for separated theater operations such as the NWI.

• International Journal of Highway Engineering
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• v.20 no.1
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• pp.77-85
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• 2018

PURPOSES : The purpose of this study was to develop an urgent road-repair system and perform a field applicability test, as well as discover the optimum mix design for machine applications compared to the optimum mix design for lab applications. METHODS : According to reviews of the patent and developed equipment, self-propelled and mix-in-place equipment types are suitable for urgent pavement repair, e.g., potholes and cracks. The machine-application mix design was revised based on the optimum lab-test mix design, and the field application of a spray-injection system was performed on the job site. The mixture from the machine application and lab application was subjected to a wet-track abrasion test and a wheel-tracking test to calibrate the machine application. RESULTS and CONCLUSIONS : This study showed that the binder content could differ for the lab application and the machine application in the same setting. Based on the wet-track abrasion test result, the binder contents of the machine application exceeded the binder contents of the lab application by 1-1.5% on the same setting value. Moreover, the maximum dynamic stability value for the machine application showed 1% lower binder contents than the maximum lab-application value. Collectively, the results of the two different tests showed that the different sizes and operating methods of the machine and lab applications could affect the mix designs. Further studies will be performed to verify the bonding strength and monitor the field application.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.967-976
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• 1996

Straw and other fibrous by-products are inevitably produced during cereal production and have traditionally been used for many purposes including feeding animals . The potential of these by -products as a feed resource for ruminants is being increasingly appreciated (FAO , 1977). In the future, the amount of cereals fed to farm animals will have to be reduced and livestock will have to rely more on by-products such as straw. The method of animal production can be classified by the major portion of feed. One is animal forage and the other is grains. In Korea , livestock farmers normally depend more than 70% upon grains for the feed stuff. The livestock production system causes the unbalance of nutrition, and results in low productivity of animal farming. In many livestock farms in Korea the rice straw is using as a major forage and the amount of rice straw fed takes 46% of total amount of required forages. Especially the rice straw is mainly using during spring, fall and winte season. However, there are still lots of problems to solved such as harvesting cost, transportation between rice farm ad livestock farm, and quality loss during drying and storage . Therefore the mechanization of straw harvesting is urgently needed to use the renewable agricultural by-products and to overcome the shortage of animal forage. The objective of this research is to develope a straw harvester with new concept which can solve the problems of the quality loss and the labor cost during drying in a field, collecting , and storage. The developed straw harvester is self-propelled machine rebuilt by rice combine and equipped with the pick-up device, the macerater and the mat-forming device.

• Journal of the Korea Society for Simulation
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• v.20 no.4
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• pp.1-11
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• 2011

In the development phase of a torpedo, the effectiveness analysis is carried out to predict the performance and to learn how to use the torpedo. In order to obtain reliable data, it is required to model the tactical situation closely to the actual one. Because the submarine is a target of a lightweight torpedo, the anti-torpedo countermeasures of a submarine such as evasive maneuvering and TACM (Torpedo Acoustic Counter Measure) should be modeled in detail. In this paper, the evasive maneuvering is modeled reflecting the movement characteristics of the submarine. Furthermore various TACMs such as a floating-type decoy, a self-propelled decoy and jammers are also modeled. Then, effectiveness of a lightweight torpedo is measured and analyzed using the simulation program which is developed through the above modeling procedure.

• Journal of Biosystems Engineering
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• v.41 no.4
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• pp.294-303
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• 2016

Purpose: This study aimed to evaluate the profitability of four selective mechanization systems in rice cultivation. Methods: Field experiments were conducted in the farmers' field during the wet season (June to November) of 2015 in Bangladesh. Mechanization systems were applied to evaluate four different selective levels (treatment) in eleven consequent operations. Seedlings were raised in a traditional seedbed and trays for manual and mechanical transplanting, respectively. Land preparation, irrigation, fertilizer, pesticide, carrying, and threshing and cleaning operations were performed using the same method in all the experimental plots. The mechanical options in the transplanting, weeding, and harvesting operations were changed. The mechanization systems were $S_1$ = hand transplanting + hand weeding + harvesting by sickle, $S_2$ = mechanical transplanting + Bangladesh Rice Research Institute (BRRI) weeder + reaper, $S_3$ = mechanical transplanting + BRRI power weeder + reaper, and $S_4$ = mechanical transplanting + herbicide + reaper. This experiment was performed in a randomized complete block design with four replications. Power tiller, rice transplanter, BRRI weeder, BRRI power weeder, self-propelled reaper, BRRI open drum thresher, and BRRI winnower were used in the respective operations. Accordingly, the techno-economic performances of the different technologies were calculated and compared with those of the traditional system. Results: The mechanically transplanted plot produced 6-10% more yield than the hand transplanted plot because of the use of tender-aged seedlings. Mechanical transplanting reduced 61% labor and 18% cost compared to manual transplanting. The BRRI weeder, BRRI power weeder, and herbicide application reduced 74, 91, and 98% labor, respectively. The latter also saved 72, 63, and 82% cost, respectively, compared to hand weeding. Herbicide application reduced the substantial amount of labor and cost in the weeding operation. Mechanical harvesting also saved 96% labor and 72% cost compared to the traditional method of harvesting using sickle. Selective mechanization saved 15-17% input cost compared to the traditional method of rice cultivation. Conclusions: Mechanical transplanting with the safe use of herbicide and harvesting by reaper is the most cost- and labor-saving operation. The method might be the recommended set of selective mechanization for enhancing productivity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.5914-5923
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• 2015

Recently, Recently, many quality problems in military supplies are raised such as K-series weapons(K-2 tank, K-9 Self-propelled artillery and K-11 Armoured Car and etc.) quality issues, leaking combat shoe issue and so on. Existing one and only national quality assurance agency for military supplies, Defense Agency for Technology and Quality(DTaQ) adapted risk management based framework to perform the government quality assurance activities. However, risk framework established by DTaQ seems lack of objectivity, consistency and efficiency. In this research, we first reviewed the DTaQ's regulations to identify the possible problems, and then suggested the alternatives which are based on advanced risk management framework and plan-do-check-action(PDCA) cycle. In conclusion, we suggested the new risk management framework, so called visual PDCA fishbone chart, and illustrated the use of the framework via real instance.

• Geomechanics and Engineering
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• v.27 no.6
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• pp.537-550
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• 2021

There are various technical problems need to be solved in the construction process of pre-setting an isolation wall into a double lane in the outburst prone mine. This study presents a methodology that pre-setting an isolation wall into a double lane without a coal pillar. This requires the excavation of two small section roadways to dig a wide section roadway, followed by construction of the separation wall. During this process the connecting lane is reserved. In order to ensure the stability of the separation wall, the required bearing capacity of the isolation wall is 4.66 MN/m and the deformation of the isolation wall is approximately 25 cm. To reduce the difficulty of implementing support the roadway is driven by 5 m/d. After the construction of the separation wall, the left side coal wall is brushed 1.5 m to make the width of the gas roadway reach 2.5 m and the roadway support utilizes anchor rod, ladder beam, anchor cable beam and net configuration. During construction, the concrete pump and removable self-propelled hydraulic wall mold are used to pump and pour the concrete of the isolation wall. In the process of mining, the stress distribution of coal body and isolation wall is detected and measured on site. The results demonstrate that the deformation of the surrounding rock of roadway and separation of roof in the roadway is small. The stress of the bolt and anchor cable is within equipment tolerance validating their selection. The roadway is well supported and the intended goal is achieved. The methodology can be used for reference for similar mine gas control.

• Journal of Korean Society for Quality Management
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• v.51 no.4
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• pp.619-632
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• 2023

Purpose: The main function of INS (Inertial Navigation System) is to measure the position of an armed vehicle and its performance is confirmed through the positioning accuracy test of Korean Defense Standards (KDS). The current standards, however, do not provide clear test methods and the conditions for performing positioning accuracy tests. Accordingly, the purpose of this study is to develop a new method for positioning accuracy test which would be effective. Methods: In this study, a new INS positioning accuracy test method is suggested based on the analysis of test data collected through a statistical experiment known as central composite design. For the positioning accuracy experiment of K105A1, a self-propelled artillery, two factors of driving velocity and driving distance are considered. Results: Based on the analysis of experimental data, a regression model for the positioning error is fitted and the positioning accuracy test of INS is so developed to maximize the positioning error. The standard proximity rate is used as an additional test criterion to evaluate the performance level of INS. Conclusion: The proposed new positioning accuracy test for INS has the advantage of finding the nonconforming items effectively. It is also expected to be utilized for the other similar INS positioning accuracy tests.

• 한국노년학
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• v.31 no.1
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• pp.157-170
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• 2011

The purpose of this article is to examine how the 'bodily culture' of older men who gather at Jongmyo Park serves to express and solidify their sense of a enduring self. The research was carried out based on the anthropological methods of participant observation and in-depth interviews at Jongmyo park and its adjacent areas. In later life, the image of a continuous self becomes harder to achieve due to the ageism prevalent in modern societies. The situation is worse at Jongmyo park since the park itself has been stigmatized as "the extraterritorial zone for the old" by the media due to the boisterous atmosphere of the park. It is dubbed as a place for those who have nowhere else to go. The singing and dancing, which used to be the dominant forms of activities at the park among older men until the 'sanctification' project propelled by the government, serves as an antidote against the ageist tendency to subjugate them. The 'bodily culture' embodies these men's image of themselves as a continuous being which has not been tarnished by the passage of time. The approach of 'body hermeneutics' is required to interpret the experiences of the body in later life.