• Korean Journal of Ecology and Environment
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• v.53 no.2
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• pp.156-164
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• 2020

The accurate estimation of fish assemblages is highly dependent on the sampling gear used for sampling. We used data from 15 sampling sites along the Nakdong River, which is a large river in South Korea, to identify differences in assemblages and sizes of freshwater fishes collected with either cast nets or gill nets, the two most commonly used sampling gear in South Korea. The two gears differed in the fish assemblages they captured, with more species caught by gill nets. Further, due to its tighter mesh size, the cast net caught significantly smaller fishes than the gill nets(independent t-test, p<0.05). We found the cast net to be appropriate for species that inhabit shallow (less than 2 m) and open water, but inappropriate for deep water, habitats with plant beds, and nocturnal species. Thus, cast net sampling is not efficient in a large river environment, and a combination of sampling methods is more suitable for understanding fish assemblages in such habitats. In general, appropriate selection of fishing methods to specific habitats is necessary to improve data quality and minimize the misrepresentation of environmental conditions.

• Journal of the Korean Home Economics Association
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• v.37 no.12 s.142
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• pp.59-67
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• 1999

This study analyzed firefighter's actual wearing condition of turnout gear The results are as fellows: 1. When a firefighter is employed, Korea applies only the minimum of firefighters stature and weight but America applies both the minimum and the maximum. The choice of size is highly related with stature more than chest circumference. 2. The satisfaction degree of thermal barrier is very low, 3%. They used rubber gloves rather than heatproof gloves. This is more serious in small country like 'up', 'myun' than in cities. For laundering, they used sprinkling method with firefighting hose. Firefigthers hoped that their clothes could be classified tv the seasons and fire places. 3. frefighter had high unsatisfaction with the movement of hands and leges in the aspect of movement adjustability, air permeability, weight, body temperature regulation, and breathing in the hygenic aspect, fire resistance, thermal resistance property, water proof, chemical reactivity and electrical conductivity. Thev were also unsatisfied with water proof boots and gloves. They were generally satisfied with helmets but firefighters over 90kg of weight were rather unsatisfied. 4. The satisfaction degree for physical fitness was very low and the items with which they were not satisfied depend on physical features. 5. To develop turnout gear, they wanted changes in design, material and size. Reflection tape need to be replaced with high quality products and they wanted the use of velcro and zipper in fastening system.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.375-380
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• 2008

This study have processed the developing of vane damper with accurate control by using gear which is a flow-control equipment of marine boiler's FD fan on this research. For the developing of vane damper, we have corrected some problem from welding & assembly process by changing the design, and for the case of an emergency case, we have applied the easy disassembly & assembly on that vane damper. Compared to Rink type vane damper in current, we have focused on high efficiency with low price of that new developing damper. For selection of actuator, we have tried to find the propriety with our developing focus. Also, we have developed a jig of assembly processing for high productivity with quality, it caused the best assembly performance with heat-treated & processed parts.

• The Journal of Fisheries Business Administration
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• v.54 no.4
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• pp.1-18
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• 2023

This study examines the significance and problems of the Fourth Amendment to the Fisheries Act, which went into effect in January 2023. Following the passage of the Aquaculture Industry Development Act, the fourth amendment to the Fisheries Act sought to reform the fisheries legislative framework, while also including significant changes. In particular, a number of new systems for managing fishing gear have been implemented, and local governments now have some autonomy in fisheries management, which has allowed for adjustments to be made to meet the needs of the fishing industry and changes in socioeconomic situations. However, as independent legislation for each fisheries sector continues, the subject of regulation under the Fisheries Act, as well as the Act's position as a basic legal system, has been continuously reduced, overshadowing the Act's objective. As a result, a full-fledged assessment of changing the legislation's name in the future is required, as well as addressing issues such as the lack of difference in the legislative purpose clause and the necessity for further revision of the definition clause. Therefore, any future revisions to the Fisheries Act should aim to overhaul the existing framework, including fishing licenses and permits.

• IE interfaces
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• v.21 no.4
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• pp.378-384
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• 2008

Small sized companies have not been successful in systematically applying statistical process control because of insufficient human resources. In this paper we present a case study of automatic checking system for a small sized company which produces various types of gears. A systematic way of automatically measuring gears is proposed and statistical analysis methods are presented. To reduce variation in the measurement data, a standard operating procedure is also proposed. This case study can be helpful to quality assurance practitioners of small sized companies who are willing to develop checking or inspection systems for their products.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.3
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• pp.654-662
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• 1998

Shift quality of an automatic transmission in a vehicle is mainly affected by transient pressures in the hydraulic system during shifting. In this study, dynamic modelings of the hydraulic system and the power train of an automatic transmission are made systematically by a bond-graph method. The dynamic characteristics of the line pressures and clutch/brake pressures during shiftings are investigated by simulations and verified by experiments. The effects of clutch/brake pressures on the shift torque are also investigated through driving simulation.

• Journal of the korean Society of Automotive Engineers
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• v.6 no.2
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• pp.39-46
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• 1984

There are various ringshaped automotive and machine parts and the study about the characteristics of ring are the important basis of the quality control and performance improvement of outer race of ball bearing, railwheel, ring gear, piston ring, and other ringshaped seals, etc. In this study, the effect of prestress which arise inevitably during the fitting of the ring shape parts and the effect of central line extension/contraction on the vibrational characteristics of ring are verified. Although many studies are made on the vibration of ring, the study about prestress and extension were rather scarce and rare. As a result of the study, a series of frequency formulas are derived. The result of this study can be utilized in the improvement of design as well as in the quality control during the fitting work.

• Journal of the Korean institute of surface engineering
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• v.43 no.5
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• pp.211-216
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• 2010

Vacuum carburizing process is well known process for its environment-friendly, low-cost, high-quality characteristics, compared with gas carburizing. In this study, a research was carried out to develop a process of vacuum carburizing for essential components of automotive transmission that is difficult to control its distortion. As a result, vacuum carburizing process is superior to gas carburizing in terms of cost, environment and quality.

• International Journal of Computer Science & Network Security
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• v.22 no.4
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• pp.237-244
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• 2022

Eco-driving of vehicles today presents an advantage that aims to reduce energy consumption and limit CO2 emissions. The application for this option is possible to older vehicles. In this paper, we propose an efficient implementation for IoT (Internet of Things) system for controlling vehicle components that affect the quality of driving (acceleration, braking, clutch, gear change) via Smartphone using Wi-Fi and BLE as communication protocol. The user can see in real-time data from sensors that control driver action on vehicle driving systems such as acceleration, braking, and vehicle shifting through a web interface. Thanks to this communication, the user can control his driving quality and, hence, eco-driving can be achieved

• Journal of KSNVE
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• v.9 no.4
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• pp.841-848
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• 1999

In the quality assurance check process of DC motor systems, even though the overall sound pressure level is acceptable, there is an incident that subjective evaluation leads to failure in product quality due to annoying noise. This kind of problem may be originated from the manufacturing or assembly process. In this paper, the transient spectral analysis, or the time-frequency analysis is applied to the noise quality problem. For the case study, the cause of annoying noise in the wind shield wiper motor is experimentally analyzed in detail. It is concluded that the defect in the shaft causes the impact noise which is not detectable by steady spectral analysis. Also demonstrated is how the time-frequency analysis is effectively applied to the annoying noise identification of the rotor-gear system.