This paper introduces a study on measuring the 3D vibration displacement of plate structure using Digital Image Correlation (DIC) applied to stereo digital continuous camera images. The proposed method is a non-contact 3D displacement measurement method that does not require physical sensors to be attached to the structure, and it has the advantage of simultaneously measuring dynamic displacements at multiple points on the structure. Theoretically, multiple cameras can be used, but in this study, two cameras were used to capture continuous images of the vibrating structure, and the image coordinates of multiple tracking points at arbitrary positions on the structure were measured using correlation matching. Using these image coordinates as input data, the dynamic 3D positions were calculated through Space intersection, successfully determining the 3D dynamic displacements. The measured dynamic displacements were validated for accuracy by comparing them with values measured by laser displacement sensors. And frequencies of measured data were validated by comparing with computational modal analysis by Finite Element Model (FEM).
The waste secondary battery contains a significant amount of valuable metals, making its recycling highly desirable. However, conventional chemical methods for recycling are environmentally unfriendly and cost-ineffective. Rather than the chemical method, this paper deals with a mechanical method for recovering electrode materials from waste secondary batteries by blowing pressurized air onto the interface area between the electrode and the separator. Especially, in this study, the effective blowing angle were searched by simulating the separation of the electrode material from the separator through 1-way fluid structure interaction analysis based on the Cohesive Zone Modeling technique.
High-strength low-alloy steel is one of the widely used materials in onshore and offshore plant engineering. We investigated the alloying effect of solute atoms in α-Fe based alloy using ab initio calculations. Empirical equations were used to establish the effect of alloying on the Vicker’s hardness, screw energy coefficient, and edge dislocation energy coefficient of the steel. Screw and edge energy coefficients were improved by the addition of V and Cr solute atoms. In addition, the addition of trace quantities of V, Cr, and Mn enhanced abrasion resistance. Solute atoms and contents with excellent mechanical properties were selected and their thermal conductivity and thermal expansion behavior were investigated. The addition of Cr atom is expected to form alloys with low thermal conductivity and thermal expansion coefficient. This study provides a better understanding of the state-of-the-art research in low-alloy steel and can be used to guide researchers to explore and develop α-Fe based alloys with improved properties, that can be fabricated in smart and cost-effective manners.
In this study, we learned about the effects of indoor radon concentration reduction associated with the operation of a mechanical ventilation system at an apartment house. The experimental parameters were mainly the indoor radon level and air change rate, which were controlled by the amount of emissions released and fan motor speed. Even at the high level of radon diffused in an apartment house, indoor radon concentrations converged to the Korean national guideline level within 3 to 4 hours when the air was ventilated at 0.5 ACH and 0.7 ACH. In the case of 0.3 ACH, however, where the degree of ventilation was insufficient compared to the legal air change rate, the high concentration indoor radon could not be sufficiently removed even if the mechanical ventilation system was operated for more than 14 hours continuously. When the indoor radon level was high, the reduction rate was 34.3% for 0.3 ACH, 70.4% for 0.5 ACH, and 69.7% for 0.7 ACH at 6 hours-operation, while at the medium-level, indoor radon can be reduced by 46.2% (0.3 ACH) to 73.2% (0.7 ACH). Depending on the indoor concentration range, it may be required to secure a ventilation rate of 0.5 ACH or more at all times. In addition, in apartment houses with excellent airtight performance, even if indoor radon is at a level similar to the national guideline, it is difficult to expect a reduction in the concentration due to natural decay. Therefore, it is desirable to lower the indoor concentrations as much as possible.
NbC, HfC, TaC, and their solid solution ceramics have been identified as the best materials for ultrahigh-temperature ceramics. However, their structural stability and elastic properties are mostly unclear. Thus, we investigated structure and elastic properties of (Nb1-xTax)C and (Nb1-xHfx)C solid solutions via ab initio calculations. Our calculated results show that the stability of (Nb1-xTax)C and (Nb1-xHfx)C increases with the increase of Hf and Ta content, and (Nb1-xHfx)C is more stable than (Nb1-xTax)C at the same content of Hf and Ta. The lattice constants decrease with increasing of Hf and Ta content. (Nb1-xTax)C and (Nb1-xHfx)C carbides are mechanically stable and brittle. Bulk modulus of (Nb1-xTax)C increases with increasing Ta content. In contrast, bulk modulus of (Nb1-xHfx)C decreases with increasing Hf content. Hardness of solid solutions shows the highest values at the (Nb0.25Ta0.75)C and (Nb0.75Hf0.25)C. In particular, (Nb0.75Hf0.25)C shows the highest hardness for the current system. The results indicate that the overall mechanical properties of (Nb1-xHfx)C solid solutions are superior to those of (Nb1-xTax)C solid solutions. Therefore, controlling the Hf and Ta element and content of the (Nb1-xTax)C and (Nb1-xHfx)C Solid solution is crucial for optimizing the material properties.
This study was designed to verify what effect the use of a natural ventilation system can have on improving indoor air quality with regard to radon in various concentration ranges in an apartment house. The results show that both high (2~3 times higher than 148 m3) and low (similar to 148 Bq/m3) levels of indoor radon concentrations can be reduced close to and/or below the Korean IAQ guideline within 6 hours when the natural ventilation system is operated at approximately an air change rate of 0.5. In the case of an air change rate of 0.3, however, the indoor radon levels cannot meet the national guidelines and the reduction effect was insufficient with regard to various radon concentrations. Typically, the air change rate of a natural ventilation system is affected by meteorological factors such as temperature, relative humidity, wind speed, pressure. Its effectiveness varies according to such factors, for that reason, the reduction effects on radon did not increase proportionally with the ventilation time in this study.
The purpose of this study is to analyze consumer preference for fish farm HACCP certification using conjoint analysis. This study used raw flatfish product to evaluate the fish farm HACCP. In this study, 500 consumers were surveyed using panel survey and stratified sampling. In the recognition analysis, the farm HACCP certification system was found to be highly recognized by consumers. It can be seen that the brand assets accumulated by existing food and agricultural HACCP certification were transfered to the fish farm HACCP and absorbed. Consumers perceived fish farm HACCP certification as similar one with existing food and agricultural HACCP. Conjoint analysis evaluated three levels factors. The attributes and levels evaluated were : price(25,800 won, 28,400 won, 31,000 won), certification(fish farm HACCP, seafood traceability, and non certified), and origin(domestic, JEJU, and WANDO). The important levels were in order of price(40.8%), certification(30.2%) and origin(29.0%). We found that consumers give higher utility to fish farm HACCP certification compared with non certified and seafood traceability certification. Market simulation results showed that the fish farm HACCP product has 12%p higher market share than non certified products. Seafood traceability certification showed 4.6%p higher market share than non certified products.
The purpose of this study is to analyze the differences by comparing consumption tendency of the Flatfish and Salmon using focus group interview (FGI). The FGI was conducted on university students in their 20s, with a total of 38 respondents surveyed in seven focus groups.
Flatfish was recognized as a food in the form of popular sliced raw fish and had customer image that fit for middle-aged men in their 40s and 50s while eating with alcohol. 20s were perceived to be out of date with their age group as flatfish was considered old fish that did not match their age. In addition, they felt low accessibility to flatfish. Salmon was perceived by 20s as a food with a higher appeal than flatfish.
Salmon has been creating a brand identity in their 20s and 30s for fashionable and trendy food that appealed to younger generations. They considered characteristics of salmon high in intangible value, such as something sophisticated, trendy, and beautiful. 20s consumed various forms of salmon including salmon sushi, salmon bowl, and salmon fillet, and they perceived it as a psychologically close food that can be easily accessible.
In this study, the color of species (orange color of salmon), accessibility, restaurant image, and social media exposure were found to influence the consumption patterns of two species.
The aim of this study is to analyze the productivity change of pollock enterprise by applying a mutually quadratic hyperbolic model and a bootstrapping model. This study used 20 units of pollock firms data (from 2013 to 2017). As a result of total productivity analysis of twenty pollock enterprises, total factor productivity was estimated to have decreased by 24.9% over the last five years (2013~2017). The main cause of this productivity decline was analyzed by technical change. In terms of annual productivity change, it showed decrease 3.0% in 2013~2014, 7.8% in 2014~2015, 4.5% in 2015~2016 and 4.7% in 2016~2017 respectively. In the analysis of productivity by corporation type, total factor productivity showed a significant decrease in both general corporation and external corporation, and productivity decrease (-29.3%) was larger than general corporation (-23.0%). In the productivity analysis by type of business, total factor productivity decreased significantly in the order of wholesale and commodity brokerage (-26.3%), food manufacturing (-25.1%) and fisheries (-15.3%). This decrease in productivity was caused by the technological change which indicates a downward shift in the production curve that is significant in all sectors.
The purpose of this paper is to suggest an export strategy of seaweed products from Korea to Vietnam by analyzing the seaweed products consumption in Vietnam. This research surveyed 217 people in Hanoi and Ho chi minh, Vietnam. The result of the research revealed that consumers in Vietnam perceived seasoned kim as a healthy and easy-to-eat Korean food with snacks and side dishes, and it was recognized as a nutritious snack especially suitable for children to 20s. Kimbap is recognized as simple and healthy Korean food that is consumed as a substitute for meals at home, on the streets, and at restaurants. Sea mustard was the healthiest among seaweeds and are consumed in the form of sea mustard soup as good food for women, children, and the elderly. Summarizing the Vietnam seaweed market, it is a market that is similar to Korean seaweed consumer culture. In conclusion, we suggested a seaweed promotion strategy targeting women in their teens to twenties, communication on seaweed production process, experiential marketing strategy and seaweed food culture strategy.
The purpose of this paper is to analyze the difference of seafood dining consumer behavior by demographic characteristics (age, gender). This research surveyed 251 people in Busan, Korea. t-test, one-way ANOVA, and MDS were used to identify the difference of consumer behavior by demographics. The result of the research revealed the difference between demographic characteristics and seafood dining consumption. 20’s showed to accept the trendy dining culture represented by salmon, sushi and shrimp, and 30’s also have similar tendency. 40’s have higher spending tendency to seafood dining like tuna restaurants. 50’s and 60’s showed conservative consumption propensity represented by grilled fish, braised fish and raw fish restaurants. In gender analysis, male have higher frequency than female about grilled eel. In the future, the seafood dining market would be reorganized with the expansion of sushi, salmon and shrimp dishes, which can be classified as a new dining market. In this research, we suggested fisheries supply and production strategies according to age and gender.
This study categorized Korean seafood diners according to their lifestyle attributes of seafood consumption. This categorization facilitated to set more detailed marketing strategies to each consumer groups so it can lead to promote seafood dining industry in Korea. For this study, a survey was conducted from September 10 to October 9, 2017 in the form of self-completed surveys from seafood restaurant diners living in Busan, Korea. A total of 251 questionnaires were collected and used for data analysis.
The results were as follows. There were eight attributes of lifestyle which Korean seafood diners have had such as ‘rationality’, ‘freshness’, ‘taste’, ‘health’, ‘ambiance’, ‘the latest trend of seafood dining’, ‘scarcity’ and ‘familiarity’.
The largest number of respondents(154 out of 251, 61.4%) responded that they considered ‘rationality’ important when choosing their seafood restaurants among the eight attributes. ‘freshness(135 out of 251, 53.8%)’ was followed. ‘the latest trend of seafood dining’ and ‘familiarity’ were the ones that the smallest number of respondents(61.4, 10.8%) considered those as significant attributes for their seafood restaurants selection.
The aim of this study is to develop suitability site indicator of urban-rural return to fishing and to analysis priority of the indicators. The study is based on literature review, expert survey and AHP(Analytic Hierarchy Process) methods. This study found 5 factors(natural environment, acceptance environment, social overhead capital, economy, fishing environment) and 21 detail variables. as a result of AHP, fisheries resources, acquisition convenience of fishing license, income(except fishing), attitude of local resident, one-person household income, high income fishing were showed high priority. This result indicate that economic foundation is most important factor for suitable site of the returning.
The purpoose of this paper is to analyze the relative effciency of dreid laver processing companies in Korea and provide the development direction and improvement plan for the dried laver industry. Data on 76 dried laver processing companies were selected as the subjects for Dea.
As a result of Dea, the average efficiency rate is shown that the technical efficiency is 84.90%, the pure technical efficiency is 93.83%, and the scale efficiency is 86.65%. and based on BCC results 38 companies are relatively efficient. comparing pure technical efficiency and scale efficiency, it showed that inefficiencies caused by scale of the company was greater than inefficiencies caused by the scale of technical matter. It implies that expanding the size is essential for achieving high-efficiency of dried laver processing company. In the inefficiency factor analysis, the result reveals that unstable supply of raw materials, quality management, capital flexibility and distribution ability influence the efficiency of laver processing company.
The aim of this study is to examine profiles of consumers in Thai seaweed market segments. A total of 321 consumers were surveyed in bangkok, thailand. The multiple regression analysis performed indicates that consumer preference toward seaweed snack is significantly influenced by seaweed consumption frequency. The cluster analysis performed indicates that there are three segments based on consumer purchasing attributes toward seaweed snack : leading type, pursuing type, beginner type. The results show that there are consumer segment with different purchasing attributes level and seaweed preference. in this study Thai seaweed market’s biggest consumer is leading type consumer(n〓40.8%) that have high level of purchasing attributes toward seaweed snack when compared to other segments. pursuing type segment(n〓27.4%) consists of consumers who have low level of purchasing attributes but have high consumption frequency. beginner type segment(n〓31.8%) consists of consumers who rarely eat seaweed snack and have high price sensitivity. This study can inform Thai seaweed consumer’s behavior and effective segment market strategies and target consumer based on purchasing behavior toward seaweed snack.
More than 90% of cultured fish is consumed by sliced raw fish which is usually an eating out menu in South Korea. In order to develop the aquaculture industry in Korea, It is very important to know whether consumers can differentiate each species or not and how consumers recognize each species by certain criteria. for example taste, seasonal preference.
The purpose of this study is to understand the competitive relationship through positioning studies of each species by the selection attributes. A total of 221 consumers were surveyed in korea.
This study adapted multidimensional scaling(MDS) analysis to explore how consumers position sliced raw fish species based on selection attributes. This study has produced perceptual maps of sliced raw fish market. Empirical data was collected from sliced raw fish consumers in Korea.
The results of MDS analysis reveal that 7 species are divided into 3 groups(flat fish, black rock fish), (red sea bream, salmon, tuna), (sea bass, gray mullet). In this study flat fish and black rock fish are perceived as safe, familiar, good value species. Red seabream, salmon, tuna are perceived as luxurious species. Sea bass and gray mullet are perceived as unfamiliar species.
The purpose of this research paper is to segment seafood market and find the factor and process that divide the segment market. Cluster analysis and in-depth interview was performed to identify meaningful segment market. The result of the research found three segment market such as seafood integration familiarity group, domestic seafood familiarity group, seafood unfamiliarity group. Seafood integration familiarity group is active consumer that consume both domestic and imported seafood at home. This group have high preference and familiarity about seafood. Seafood familiarity group purchase imported seafood for the reason that imported seafood is cheaper than domestic seafood and have similar quality level. Domestic seafood familiarity group consume mostly domestic seafood and not purchase imported seafood for the reason that imported seafood have low quality and safety. This group have high preference and familiarity about seafood. Seafood unfamiliarity group is low preference group about seafood and seldom eat at home. This study found that the main factor that divide segment market is seafood familiarity that formed by experiencing seafood in youth and seafood familiarity is main factor that determine consumption degree of seafood at home.
광범위큰 B세포 림프종은 비호지킨림프종의 대표적인 아형으로 공격적 림프종이며 원발성으로 담낭에 발생한 림프 종은 일부 증례를 통한 보고가 있지만, 담낭에 단독 재발한 광범위큰 B세포 림프종은 국내에서 보고된 바가 없다. 본 증례는 상복부의 통증과 황달의 임상증상 및 복부컴퓨터단층 촬영 그리고 양전자 방출 단층촬영에서 만성 담낭염과 담낭 암으로 추정하여 수술 후 조직검사를 통해 재발한 광범위큰 B세포 림프종으로 진단할 수 있었다. 저자들은 과거 회장에 발생한 광범위큰 B세포 림프종으로 치료를 시행하여 완전완 화가 유도된 이후 다른 장기 혹은 림프절 전이 없이 단독으로 담낭에 재발한 광범위큰 B세포 림프종 1예를 경험하였기에 문헌 고찰과 함께 보고하는 바이다.