• Journal of Advanced Navigation Technology
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• v.24 no.3
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• pp.173-183
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• 2020

This research focused on such a passenger sample that used to fly between Incheon int'l airport(ICN) and Dubai int'l airport(DXB) using either a national carrier or gulf carriers because the route between ICN and DXB is one of the international air routes with the toughest competition under the global pressure of open air transport market. Based on the results from the empirical research, this paper proposed a competitive advantage which a national carrier must have to cope with global competition under the open sky policies and implications for sustainable strategies of them. National carrier passengers perceived product benefits had a significant positive effect on price reliability in spite of lower price competitiveness. Following the empirical analysis results, it was proven a national carrier should try to improve product benefit sought by passengers to maintain sustainable competitive advantage in the market against foreign airlines.

• Journal of the Ergonomics Society of Korea
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• v.31 no.2
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• pp.379-388
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• 2012

Objective: This study developed a new shower carrier prototype to reduce caregivers' muscle burden and to increase use convenience by reflecting the needs of domestic long-term care institutions. Background: In the long-term care institutions, one of the ADL(Activities of Daily Life) factors is bathing/showering. Recently, bath/shower-assisting equipment is actively being introduced in care institutions to reduce the caregivers' care cost, but most of the domestic equipment was designed to imitate foreign products and rarely reflected the needs of care institutions. Method: Based on Korean elderly people's body information, the bed size(length: 1,900mm, width: 650mm) was set-up, and a variable headrest with a newly designed headform was developed to provide the comfort for the elderly and convenience for caregivers. To reduce caregivers' muscle burden on transferring and showering activities, a 3-step column lifting module equipped with dual actuators(lowest/highest levels from the ground: 600/1,100mm, Stroke: 500mm) was developed, and the wheelbase parameter(length: 1,250mm, width: 580mm) was defined securing the turn-over safety of the shower carrier. The drivability tests were performed for the prototype and foreign product, and the male and female subject's muscle activities were measured through the tests. Results: The structural stability of the shower carrier prototype was secured by finite element analysis, and the muscle activities of the subjects through the drivability tests largely decreased in the prototype, compared to the foreign product. Conclusion: In this study, a new shower carrier prototype was developed to possibly reduce caregivers' muscle burden and to increase use convenience based on the needs of long-term care institutions. It was expected that the drivability performance of the prototype could be relatively superior to that of the foreign product. Application: The results obtained from the study can be applied for the optimal development of a shower carrier including other equipment to effectively care for the elderly.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.1
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• pp.81-86
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• 1997

Spray dried powdered juice was processed from concentrated extract of jujube(Zizyphus jujuba MILLER). Spray drying of the extract solution could not be operated to have powder product by itself over whole concentration range and required addition of some carrier or support material. The concentrated extract of 26$^{\circ}$Bx was combined with carrier material solution to have a final concentration of 30$^{\circ}$Bx, and then spray dried. Proper addition level of carrier solid for physical and flavor quality of the powder product was determined to be 1 : 1 ratio to jujube solid. Combined use of maltose and gum arabic produced the best quality product among the studied carrier materials, which were maltose, dextrin, condensed milk and gum arabic. Enzymatic treatment in extraction process could increase the yield by 13~39%, but hurt the sensory quality of powdered juice. Treatment by 0.5% pectinase(0.05 unit/ml) may be used with lesser quality change for improved yield.

• Journal of the Korea Safety Management & Science
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• v.17 no.2
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• pp.161-175
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• 2015

This study analyzed that the infant carrier standard affects the satisfaction of certification. Baby Carrier Safety requirements in the Republic of Korea is enforceable by court duty certification. Therefore, a test was conducted to compare with the safety requirements of the United States and Europe and the survey was conducted to know how much manufacturers and importers are satisfied with the certification. According to the test result, there is a difference between domestic and foreign safety requirements about flame retardancy. As a result of the survey, The satisfaction of the certification is proportionate to the one of product standard.

• Journal of the Society of Naval Architects of Korea
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• v.46 no.3
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• pp.279-289
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• 2009

For a Product Oil Carrier, longitudinal bulkhead as well as transverse one is corrugated shape in general and intersection part of bulkheads is utilized for a pipe trunk. Since lower and upper stools are to be connected with all of longitudinal and transverse bulkheads, they have a uniform height respectively. The purpose of this study is the development of design system for the minimization of total weight of longitudinal and transverse bulkheads at the initial design stage. In this study, the beam element models for longitudinal and transverse corrugated bulkheads are established and they are applied to the structural analysis. For the practical design, the selection and the position of an additional pipe trunk are considered in this study. In addition the required minimum distance between the bracket installed along the web of corrugation at lower stool and the diaphragm is taken into consideration during optimization process. Evolution strategy(ES) is adopted as an optimization technique.

• Journal of the Society of Naval Architects of Korea
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• v.53 no.6
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• pp.456-464
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• 2016

To design the modified hull form with relatively unfavorable dimensions and constraints than the parent ship the stepwise design was applied. In each design step the resistance characteristics was estimated by numerical calculations using CFD programs as Wavis 1.4, Wavis 2.1 and Fluent 12.1. The wave profiles along hull surface by potential flow calculations were investigated to improve wave resistance by modifying the bow shapes. To improve the stern shapes with a point of viscous form resistance the pressure distributions on hull surface and the limiting streamlines are investigated by viscous flow calculations. The design objectives such as shortening the LBP, enlarging the propeller tip clearance, moving forward of the LCB location and increasing the displacement were applied by stepwise to develop the new hull form of DWT 75,000 product oil carrier. Finally a new hull form was developed without the resistance performance loss compared with the parent ship.

• Journal of Positioning, Navigation, and Timing
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• v.1 no.1
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• pp.7-14
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• 2012

Due to inaccurate safe navigation estimates, maritime accidents have been occurring consistently. In order to solve this, the precise positioning technology using carrier phase information is used, but due to high buildings near inland waterways or inclination, satellite signals might become weak or blocked for some time. Under this weak signal environment for some time, the GPS raw measurements become less accurate so that it is difficult to search and maintain the integer ambiguity of carrier phase. In this paper, a method to generate code and carrier phase measurements under this environment and maintain resilient navigation is proposed. In the weak signal environment, the position of the receiver is estimated using an inertial sensor, and with this information, the distance between the satellite and the receiver is calculated to generate code measurements using IGS product and model. And, the carrier phase measurements are generated based on the statistics for generating fractional phase. In order to verify the performance of the proposed method, the proposed method was compared for a fixed blocked time. It was confirmed that in case of a weak or blocked satellite signals for 1 to 5 minutes, the proposed method showed more improved results than the inertial navigation only, maintaining stable positioning accuracy within 1 m.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.45 no.3
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• pp.49-56
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• 2022

ROK Navy intends to secure the Korean-type aircraft carrier in order to effectively prepare for various future security threats. In general, the Korean national competency is considered to be at the level of having an aircraft carrier, but it is unclear what scale aircraft carrier would be appropriate. In this study, the efficiency was evaluated through the relative comparison between national competency(national power, economic power) and the scale of aircraft carriers, and the optimal scale of the Korean-type aircraft carrier that could be acquired was presented. A DEA(Data Envelopment Analysis) model was applied to aircraft carriers(19 aircraft carriers in 11 countries) currently in operation and scheduled to be possessed in the world. As input variables, CINC(Composite Index of National Capability) and GDP(Gross Domestic Product), which are the most widely used as indicators of national and economic power, and as output variables, the full-load displacement, length, and width of aircraft carriers were selected. ARIMA(short-term within 5 years) and simple regression(long-term over 5 years) were used to estimate the future national competency of each country at the time of aircraft carriers acquisition. The relative efficiency score of the Korean-type aircraft carrier currently being evaluated is 1.062, and it was evaluated as small-scale aircraft carrier compared to the national competency. Based on Korean national competency, the optimal scale of the Korean-type aircraft carrier calculated by aggregating benchmark groups, is 58,308.1 tons of full-load displacement, 279.4m in length, and 68.3m in width.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.4A
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• pp.440-449
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• 2008

In this paper, we propose a 16-QAM carrier recovery loop which is suitable for the implementation of Inmarsat M4 system receiver. Because the frequency offset of ${\pm}924\;Hz$ on signal bandwidth 33.6 kHz is recommended in Inmarsat M4 system specification, carrier recovery loop having stable operation in the channel environment with large relative frequency offset is required. the carrier recovery loop which adopts only PLL can't be stable in relatively large frequency offset environment. Therefore, we propose a carrier recovery loop which has stable operation in large relative frequency offset environment for Inmarsat M4 system. The proposed carrier recovery loop employed differential filter-based noncoherent UW detector which is robust to frequency offset, CP-AFC for initial frequency offset acquisition using UW signal, and 16-QAM DD-PLL for phase tracking using data signal to overcome large relative frequency offset and achieve stable carrier recovery performance. Simulation results show that the proposed carrier recovery loop has stable operation and satisfactory performance in large relative frequency offset environment for Inmarsat M4 system.

• Transactions of Materials Processing
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• v.14 no.3 s.75
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• pp.207-214
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• 2005

Blanking process is widely used fur producing various structural parts. However, fine blanking technology is frequently used as a single step blanking operation with clean cut surface of a sheared surface because the fractured surface of parts causes serious problems in the final product and therefore it must be removed by the post-processing in case of the conventional blanking. In the present investigation, a fine blanking process was designed within the framework of progressive die to produce a carrier plate assembled within the auto transmission. Finite element analysis of the shearing behavior at the respective stage of the progressive fine blanking was conducted to validate the designed die parameters. Finally the designed progressive fine blanking process was experimentally evaluated by using the machined die.