• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.1
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• pp.81-86
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• 2013

Exhaust gas from a small portable electric generator is simply exhausted to the surroundings because the capacity and quality of the waste heat of this gas is generally not sufficient to recover and utilize. We have proposed a seawater distiller utilizing the thermal energy of waste gas from an electric generator. The distiller recovers heat from the waste gas by means of a heat pipe and uses it effectively through a multiple-effect diffusion-type structure. We constructed an experimental apparatus with a vertical single-effect still having a 4-stroke 50 cc generator engine and found that the experimental results for distillate productivity show good agreement with the theoretical predictions. The results show that the distiller can recover 52 W of waste heat from the gas at $171^{\circ}C$, and ~85% of the recovered heat can be utilized for distillation to produce 70 g/h of fresh water. This is equivalent to a productivity of 500 g/h in the case of a 10-effect still. Therefore, the proposed distiller should be useful in remote areas where electricity and water grids are inadequate.

• Journal of Animal Science and Technology
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• v.48 no.3
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• pp.479-486
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• 2006

The current study was conducted to examine the effect of feeding and management practices on milk quality and dairy farm productivity in Korea. Fifty dairy farms in Gyunggi (11), Gangwon (22), Chungnam (17) provinces were surveyed to collect data on the herd size, housing style, feeding management, waste disposal, milking practices and milk yield. Milk tank samples from all farms under study were also collected to enumerate its composition and quality parameters. Large dairy herds are equiped with better housing, milking and waste control facilities than medium and small dairy herds. Higher concentrate feeding to lactating cows was noticed in small dairy herds (47.51 %) than in medium (32.59 %) and large dairy herds (31.82 %). The decrease in concentrate feeding to lactating cows with increase in number of cows per farm resulted in a simultaneous increase in the use of imported forages. Bacterial count in milk was affected by housing and milking facilities at dairy farms. Higher bacterial counts (Coliform and E. coli) in milk were observed in cows housed in stanchion than those under free stall with saw dust bedding. The bacterial counts were higher with bucket milking system than with pipe-line and parlour systems. The increase in the number of dairy cows per farm and thus better management and milking facilities resulted in a reduction in somatic cell score. Milk yield (per cow) was higher in herds with less somatic cell score. Average milk protein concentration was between 2.89 to 2.98 % and milk urea nitrogen was between 21.81 to 23.31mg/ml on surveyed dairy farms. This study concluded that large herd size with better dairy cow management facilities is crucial to produce quality milk with better dairy farm income.

• Journal of Internet of Things and Convergence
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• v.9 no.6
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• pp.93-98
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• 2023

In paddy rice farming, water management is a critical task. To suppress weed emergence during the early stages of growth, fields are deeply flooded, and after transplantation, the water level is reduced to promote rooting and stimulate stem generation. Later, water is drained to prevent the production of sterile tillers. The adequacy of water supply is influenced by various factors such as field location, irrigation channels, soil conditions, and weather, requiring farmers to frequently check water levels and control the ingress and egress of water. This effort increases if the fields are scattered in remote locations. Automated irrigation systems have been considered to reduce labor and improve productivity. However, the net income from rice production in 2022 was about KRW 320,000/10a on average, making it financially unfeasible to implement high-cost devices or construct new infrastructure. This study focused on developing an IoT-Based irrigation valve that can be easily integrated into existing agricultural infrastructure without additional construction. The research was carried out in three main areas: Firstly, an irrigation valve was designed for quick and easy installation on existing agricultural pipes. Secondly, a power circuit was developed to connect a low-power Cat M1 communication modem with an Arduino Nano board for remote operation. Thirdly, a cloud-based platform was used to set up a server and database environment and create a web interface that users can easily access.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.94-100
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• 2021

To improve the productivity of cargo containment construction for a membrane LNG carrier, it is important to shorten the installation period and process of the scaffolding system, which is a construction workbench of a cargo containment for a membrane LNG carrier. As an effective method, opinions are being gathered to enlarge the lifting unit from the existing two stages to eight stages. On the other hand, the stresses around the pin and hole will increase significantly because of the increase in lifting load according to the large size of the module. The purpose of this study was to establish a new large module-lifting plan by introducing TRIZ to solve these problems. This study adopted a method to utilize 40 inventive principles, which is one of the various problem-solving tools of TRIZ. First, technical contradictions were derived, the engineering parameters were selected. Second, efficient inventive principles were selected to overcome the technical contradictions using a contradiction matrix. Finally, the general and specific solutions were derived through the selected inventive principle, and structural analysis confirmed that the stress generated in the structure was low. The utility of TRIZ was confirmed by the successful lifting of large modules using the established lifting method.

• Journal of the Society of Naval Architects of Korea
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• v.33 no.1
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• pp.40-53
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• 1996

In this paper, the wave drift damping is studied. An approximate method is adopted to calculate the wave drift damping for the sake of practical applications. By assuming the ship's forward speed to be low, the Green function and the velocity potential are expanded asymptotically with respect to the Brard number(${\tau}$) and terms up to the first order of ${\tau}$ are retained. Mean wave drift forces are computed straightforwardly. The wave drift damping is estimated as the change rate of the mean wave drift force with respect to the ship's speed. In order to validate the present method, Series 60(Cb=0.7) ship is exemplified for forward speed of Fn=0, 0.02 and 0.04. To predict the wave drift damping experimentally, three geosym models of the Esso-Osaka tanker are used. Also the effect of drift angle on the wave drift damping is also considered. Comparisons between numerical and experimental results show reasonable agreements.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.11
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• pp.403-408
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• 2014

In the Internet of Things(IoT) era, many of the things or objects that enclose our environments are able to associate with those things on the Internet. To construct IoT systems, it needs to consider a component for acquiring and aggregating of sensory data via things with sensors and instruments, which is connected by diverse networks, in IoT environment. An IoT system is intrinsically distributed in a variety of ways. In addition, to manage an IoT system efficiently, interoperability is needed to meet requirements while the IoT system is designed to deliver data among its applications. In this paper, a reference architecture based on asynchronous messaging is defined and used for designing an IoT system. To apply the architecture, we discuss how to manage data streams with real-time characteristics and make a prototype based on pipe-and-filter to produce and consume them by a pub/sub messaging system NaradaBrokering.

• Journal of the Korean Institute of Gas
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• v.14 no.1
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• pp.47-54
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• 2010

In order to reduce the number of installation processes and the cost, a unified ball valve and polyethylene-steel pipe is proposed and tested. An integrated design approach is carried out such that a virtual manufacturing based on finite-element analysis is first performed in order to examine contact conditions under exaggerated temperature variations (${\Delta}T\;=\;60^{\circ}C$ and $-50^{\circ}C$ for summer and winter, respectively). From the final design configuration, it was predicted that the maximum contact pressures are 71 and 8.1 MPa for summer and winter, respectively, at relatively larger contact surface. Based on this observation, a prototype model is fabricated to go through an actual leakage test. The prototype pipe passed a hydrostatic strength test successfully, showing no leakage at even much higher (54 MPa) than the operational pressure (0.25 MPa).

• KIPS Transactions on Software and Data Engineering
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• v.11 no.5
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• pp.211-220
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• 2022

Recently, research on smart factories triggered by the 4th industrial revolution is being actively conducted. Accordingly, the manufacturing industry is conducting various studies to improve productivity and quality based on deep learning technology with robust performance. This paper is a study on the method of detecting tire surface defects in the visual inspection stage of the tire manufacturing process, and introduces a tire surface defect detection method using a depth image acquired through a 3D camera. The tire surface depth image dealt with in this study has the problem of low contrast caused by the shallow depth of the tire surface and the difference in the reference depth value due to the data acquisition environment. And due to the nature of the manufacturing industry, algorithms with performance that can be processed in real time along with detection performance is required. Therefore, in this paper, we studied a method to normalize the depth image through relatively simple methods so that the tire surface defect detection algorithm does not consist of a complex algorithm pipeline. and conducted a comparative experiment between the general normalization method and the normalization method suggested in this paper using YOLO V3, which could satisfy both detection performance and speed. As a result of the experiment, it is confirmed that the normalization method proposed in this paper improved performance by about 7% based on mAP 0.5, and the method proposed in this paper is effective.

• Journal of the Korean Institute of Gas
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• v.5 no.3 s.15
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• pp.45-50
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• 2001

Open rack vaporizer (ORV) has been used in liquefied natural gas (LNG) receiving terminal in order to vaporize LNG into natural gas (NG) by heat exchange with seawater The U-type ORV which had been operated with seawater for 14 years is one of the important utilities of the gas production and the weld part of tube connected with header_ pipe had experienced many corrosion problems. To elucidate the cause of corrosion at weld part of vaporizer tube, corrosion potentials were compared by parts. This study concerns on the measurement of corrosion pit depth using non-destructive method and the evaluation of stress distribution in an aspect of safety with finite element analysis. In order to confirm the reliability of galvanic corrosion between weld parts and base metal, the measurement of corrosion potential by parts was conducted for 20 minutes in 3.5$\%$(wt.) NaCl solution. Many non-destructive methods were tried to measure the remaining thickness of vaporizer tube at fields. For general corrosion, tangential radiography test was confirmed as an effective method. In case of a fine corrosion pit, the shape of corrosion pit was reproduced using surface replication method. From collected data, stress distributions were quantitatively evaluated with 2-dimensional finite element method and the diagnostic evaluation on internal pressure of the U-type vaporizer could be made.

• The Journal of the Korea Contents Association
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• v.17 no.1
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• pp.444-454
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• 2017

Stop-motion animation is highly valued for realistic imagery and its ability to captivate the five senses of the audience. Despite this, practical research in this area is limited to date. The long hours required to produce stop-motion animation and turn these into profits can be attributed for the lack of knowledge in this area. In production research, the matter is made worse as it is difficult to protect the intellectual property made through the collaborated efforts of students and teaching staff through each laborious stage of planning, broadcasting and making 2D models. Meanwhile as the animation industry finds the investigation of new production processes taxing, it has maintained its focus on pre-existing processes such as the use of pipeline. This paper aims to shed light on new production methods that can be used to improve the effectiveness of existing stop-motion production. In addition, by working with Taktoon Enterprises on its T.V series Galaxy Kids the paper will revise real world production methods including the traditional use of hand made models. Thus by investigating the use of graphic technology such as 3D printing the paper will be able to extend current business models. Research conducted in this paper is a necessary part of overcoming various contents production obstacles. Furthermore, it may help publicize issues faced in production leading to the discussion and sharing of new innovations.