• Korean journal of food and cookery science
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• v.29 no.1
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• pp.63-71
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• 2013

The purpose of this study was to analyze the gap between importance and performance in perceived sanitation management for general hospital foodservice operations. Data were collected through surveys given to 168 hospital dietitians in the Seoul-Incheon, Gyeonggi-do, Daegu, and North Gyeongsang province. The 65 questionnaires from total questionnaires were usable and the response rate was 38.7%. All statistical analyses were conducted using the SPSS package program (version 20.0) for t-test, ANOVA, and importance-performance analysis (IPA). According to the importance and performance analysis for 26 items, the importance score was significantly higher than the performance score for 22 items. In addition, the results of IPA showed the following areas as improvement priorities: handling foods on working table and management of distribution temperature. In conclusion, the performance level of prerequisite programs applying to the hospital foodservice needs improvement, especially cross-contamination prevention and temperature control for distribution. Additionally dietitians should be educated about sanitation management items that perceived to be less important than the others.

• Smart Structures and Systems
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• v.25 no.3
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• pp.311-322
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• 2020

This paper studies the influence of parameters of a novel SMA helical spring energy dissipation brace on the seismic resistance of a frame structure. The force-displacement relationship of the SMA springs is established mathematically based on a multilinear constitutive model of the SMA material. Four SMA helical springs are fabricated, and the force-displacement relationship curves of the SMA springs are obtained via tension tests. A numerical dynamic model of a two-floor frame with spring energy dissipation braces is constructed and evaluated via vibration table tests. Then, two spring parameters, namely, the ratio of the helical spring diameter to the wire diameter and the pre-stretch length, are selected to investigate their influences on the seismic responses of the frame structure. The simulation results demonstrate that the optimal ratio of the helical spring diameter to the wire diameter can be found to minimize the absolute acceleration and the relative displacement of the frame structure. Meanwhile, if the pre-stretch length is assigned a suitable value, excellent vibration reduction performance can be realized. Compared with the frame structure without braces, the frames with spring braces exhibit highly satisfactory seismic resistance performance under various earthquake waves. However, it is necessary to select an SMA spring with optimal parameters for realizing optimal vibration reduction performance.

• Journal of Climate Change Research
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• v.7 no.1
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• pp.59-68
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• 2016

The world's major countries have focused on the renewable energy industry as the solution to climate change and the energy crisis. Nevertheless, there are no studies on the economic effects of the renewable energy industry. This study analyzed the economic effects of Korea's renewable energy industry by using the 2010 Input-Output Table. It is estimated that Korea's renewable energy industry made a production-induced effect of 2.0262 won, and a value-added-induced effect of 0.6138 won through an increase in output growth of 1 won, and an employment-induced effect of 2.3046 labors through an increase in output growth of 1 billion won. Both the effect ratio and the response ratio were greater than 1, which means the renewable energy industry is an intermediate manufacturing industry whose forward linkage effect and backward linkage effects are large. These results show differences with previous studies that classified electricity sector and renewable energy industry into final primary production industries. It is expected that the economic effects of the renewable energy industry will become greater in the future. Therefore, research on statistics related to the renewable energy industry is needed for more precise analysis.

• Journal of Korean Association for Spatial Structures
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• v.18 no.4
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• pp.49-59
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• 2018

Wireless sensors are more favorable in measuring structural response compared to conventional sensors. This is because they are easier to use with no issues with cables and are considerably cheaper. There are several applications that can be used in recording and analyzing data from MEMS sensor installed on an iPhone. The Vibration App is one of the applications used and there has not been adequate research conducted in analyzing the performance of this App. This paper analyzed the performance of the Vibration App by comparing it with the performance of an ICP sensor. Results show that natural frequency results are more accurate (error less than 5%) in comparison to the amplitude results. This means that built- in MEMS sensor in smartphones are good at estimating natural frequency of structures. In addition, it was seen that the results became more accurate at higher frequencies (5.0Hz and 10.0Hz).

• Journal of Soil and Groundwater Environment
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• v.24 no.5
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• pp.17-30
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• 2019

Intensive agricultural development in Mexicali valley, Baja-California, Mexico, has induced tremendous strain on the limited water resources. Agricultural water consumption in the valley mainly relies on diversions of the Colorado River, but their water supply is far less than the demand. Hence, the use of groundwater for irrigation purposes has gained considerable attention. To account for these changes, it is important to evaluate surface water and groundwater conditions based on historical water use. This study identified the effects of agricultural activities on groundwater levels and groundwater recharge in the Mexicali valley (in irrigation unit 16) by a comprehensive MODFLOW Farm process (MF-FMP) numerical modeling. The MF-FMP modeling results showed that the water table in the study area is drawn downed, more in eastern areas. The inflow-outflow analysis demonstrated that recharge to the aquifer occurs in response to agricultural supplies. In general, the model provides MF-FMP simulations of natural and anthropogenic components of the hydrologic cycle, the distribution and dynamics of supply and demand in the study area.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.1
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• pp.134-137
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• 2020

Recently, there are emphasized to support the maintenance and management system of vessels using acquired data from engine part equipment. But, there are limitations for data exchange and management. To solve the problem, the ISO published ISO 19847 and 19848. In this paper, we analyze the ISO 19848 requirements related to identify data channel ID for ship equipment, and propose the examples for applying encoding techniques. In addition, we suggest the proposed technique for applying of managing the failure and maintenance type of the ship's engine part facilities by examples. If this method is applied, the vessel's equipment can exchange data through the sharing of the code table, and express what response is needed or acted, including where the failure occurred.

• Structural Engineering and Mechanics
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• v.82 no.6
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• pp.735-745
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• 2022

The suspension thyristor valve can generate tremendous vertical acceleration responses in layers and large tension forces in hangers. A shaking table test of a scaled-down model of thyristor valves suspended on a hall building is performed to qualify the risk of vertical uplift of two representative types of valves, the chain valve and the rigid valve. Besides, an analytical model is established to investigate the source of the slackening of hangers. The test results show that the valves frequently experience a large vertical acceleration response. The soft spring joint can significantly reduce acceleration, but is still unable to prevent vertical uplift of the chain valve. The analytical model shows a stiffer roof and inter-story connection both contribute to a higher risk of vertical uplift for a rigid valve. In addition, the planar eccentricity and short hangers, which result in torsional motion of the valve, increase the possibility of vertical uplift for a chain valve. Therefore, spring joints with additional viscous dampers and symmetric layout in each layer are recommended for the rigid and chain valve, respectively, to prevent the uplift of valves.

• Structural Engineering and Mechanics
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• v.86 no.1
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• pp.29-48
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• 2023

Pounding happens when contiguous structures with differing heights vibrate out of line caused by a seismic activity. The situation is aggravated due to the insufficient separation gap between the structures which can lead to the crashing of the buildings or total collapse of an edifice. Countries around the world have compiled building standards to address the pounding issue. One of the strategies recommended is the introduction of the separation gap between structures. AS1170.4-2007 is an Australian standard that requires 1% of the building height as a minimum separation gap between buildings to preclude pounding. This article presents experimental and numerical tests to determine the adequacy of this specification to prevent the occurrence of seismic pounding between steel frame structures under near-field and far-field earthquakes. The results indicated that the recommended minimum separation gap based on the Australian Standard is inaccurate if low-rise structure in a coupled case is utilised under both near and far field earthquakes. The standard is adequate if a tall building is involved but only when a far-field earthquake happens. The research likewise presents results derived by using the ABS and SRSS methods.

• Smart Structures and Systems
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• v.31 no.5
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• pp.455-467
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• 2023

Impact damper is a passive damping system that controls undesirable vibration with mass block impacting with stops fixed to the excited structure, introducing momentum exchange and energy dissipation. However, harmful momentum exchange may occur in the random excitation increasing structural response. Based on the mechanism of impact damping system, a semi-active impact damper (SAID) with controllable impact timing as well as a semi-active control strategy is proposed to enhance the seismic performance of engineering structures in this paper. Comparative experimental studies were conducted to investigate the damping performances of the passive impact damper and SAID. The extreme working conditions for SAID were also discussed and approaches to enhance the damping effect under high-intensity excitations were proposed. A numerical simulation model of SAID attached to a frame structure was established to further explore the damping mechanism. The experimental and numerical results show that the SAID has better control effect than the traditional passive impact damper and can effectively broaden the damping frequency band. The parametric studies illustrate the mass ratio and impact damping ratio of SAID can significantly influence the vibration control effect by affecting the impact force.

• Journal of the Korean Society of Food Culture
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• v.21 no.5
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• pp.463-472
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• 2006

The purpose of this study was to investigate university students' attitudes and interests for ethnic food. The questionnaire developed was distributed to 60 students majoring in food & nutrition and 260 students taking a liberal course related with food culture in world. A total of 271 questionnaires were usable ; resulting in 84.7% response rate. Among 12 kinds of ethnic food, a large number of students had an experience in Japanese, Chinese, American and Italian food. Also Chinese, American, Japanese and Italian food were familiar with them, but the hope to eat for French, Spanish, Mexican and German food was too strong. Students knew kinds, characteristics, table manners and etc. for Japanese, Chinese, and American food very well and wanted to know the information about French food. as result of positioning for ethnic food by correspondence analysis, Spanish, English, French, Germany and Mexican food had a strong image in want to eat, wanted to know information about food and got a good feeling. Students perceived Vietnamese, Thai and Indian food as having an experience, Japanese, American and Italian food as well-know about food or restaurants, and Chinese food as being familiar. The findings would indicate trends for ethnic foods and their cultures in Korea and forecast the possibility of change in foodservice market.