• Title/Summary/Keyword: Product quality

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Market evaluation and marketing strategy to expand the consumption of Pleurotus nebrodensis variety 'Uram' (백령느타리 '우람'의 소비확대를 위한 시장평가와 마케팅 전략)

  • Kim, Yeon-Jin;Lee, Ja-Young;Kim, Jeong-Han;Choi, Jun-Yeong;Lee, Chae-Young;Lee, Chan-Jung;Lim, Gab-June
    • Journal of Mushroom
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    • v.20 no.3
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    • pp.173-177
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    • 2022
  • Mushroom production in Korea is concentrated on five major mushroom types. To create a new source of income for farmers, it is necessary to establish new mushroom production and marketing systems. This study was conducted to evaluate the marketability of and establish a marketing strategy for Pleurotus nebrodensis variety 'Uram'. The evaluation of distributors showed that it was necessary to cultivate mushrooms of uniform shape and size, to compensate for their low storability, and to sell them in small packages. The consumer evaluation showed that the texture of P. nebrodensis had the highest level of satisfaction for quality, but the levels of satisfaction for size and shape were low. In the consumer evaluation, as in the distributor evaluation, improvements in cultivation were found to be necessary, as the storage time is short due to a high moisture content. An evaluation of the market gave the following results regarding the marketing strategy. It was found to be necessary to consider the production of mushrooms of a uniform shape and size and sell them in small packages in the range of 150 to 300 g. The price of the mushrooms should be set using a high-end strategy for high-end sales. The mushrooms should be introduced to local food and eco-friendly stores in the early stages of production. Subsequently, if farmhouse production increases, shipments should be made to wholesale markets through a regular contract. Finally, considering that P. nebrodensis is an unfamiliar mushroom to consumers, it is necessary to promote it by increasing the accessibility of consumers through tasting events and experience groups.

Microbiological Hazard Analysis of Sundae (Korean Sausage) Made of Meat By-Products (식육 부산물을 활용한 순대의 미생물학적 위해 분석)

  • Cheong, Jin-Sook;Kim, Yun Jeong;Om, Ae-Son
    • Journal of Food Hygiene and Safety
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    • v.37 no.3
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    • pp.181-188
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    • 2022
  • Despite the recent increase in the consumption level of the processed meat-byproducts, the health and safety issue has consistently been raised in the processes of production, distribution and consumption. The purpose of this study is to analyze and evaluate the microbiological hazard elements in the Korean sausage, "Sundae," to present not only the safety standard of meat by-product vendors based on HACCP (Hazard Analysis Critical Control Point), but also the quality control criteria and sanitary arrangements of small manufacturers. For the study, the microbiological hazards in 24 raw materials, 7 manufacturing processes, 40 facilities and tools, 17 workplace environment, and 12 workers were analyzed. The analysis revealed the hazardous elements in the initial stages with 6.28 and 4.07 log CFU/g of total aerobic count and coliforms, respectively, detected from the porcine blood and 3.23 log CFU/g of coliforms from the porcine small intestines. The result also showed that the total aerobic counts and coliforms in the process of mixing and filling process exceeds the standards in the hygiene guidelines by Natick with the total aerobic counts of 5.23, 5.45 log CFU/g, and the coliforms of 3.25, and 3.31 log CFU/g, respectively. Although the detected total aerobic count and the coliforms in the filling and washing rooms exceeded the standards, it was found that the total aerobic count was significantly reduced by 98% after cleaning and disinfecting and no coliforms was detected in any process thereafter. In order to achieve high level of safety in the manufacturing processes of Sundae, the separation of washing and disinfection room from the other sections and the sanitation control of the workers must be preceded, along with strict monitoring in the storage and distribution processes. The study raises necessity for additional studies for the safety evaluation of the processed meat-byproducts and further researches on the validity of the critical limits.

Hazardous Metal Content in Tattoo Cosmetics and Tattoo Inks (타투화장품 및 문신용 염료의 유해금속 함량 연구)

  • Mi Sun Kim;Su Un Kim;Sam Ju Jung;Young Eun Kim;Min Jung Kim;Myung Sook Lee;In Sook Hwang
    • Journal of Environmental Health Sciences
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    • v.49 no.2
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    • pp.66-77
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    • 2023
  • Background: Along with the increase in consumer interest in and consumption of tattoo products, the controversy over harmful heavy metals associated with the use of tattoo cosmetics is also increasing. Therefore, investigation of hazardous metals in these tattoo products is needed. Objectives: This study was performed to provide useful data for establishing reasonable standards to securely manage tattoo cosmetics, tattoo stickers, and tattoo inks distributed in the market. Methods: Thirteen kinds of hazardous metal contents (Pb, As, Cd, Sb, Ni, Co, Cu, Cr, Se, Ba, Zn, Sn, and Hg) were analyzed for 23 tattoo cosmetics, ten tattoo stickers, and 16 tattoo inks. Hg was measured through the combustion-gold amalgamation method, and other hazardous metals were measured by inductively coupled plasma-mass spectrometry (ICP-MS) after acidic decomposition using a microwave apparatus. Results: The detected ranges of Pb, As, Cd, Sb, Ni, and Hg in tattoo cosmetics were 0.07~1.18, 0.06~0.41, ND~0.07, 0.01~3.44, 0.12~2.75, and ND~0.01 ㎍/g, respectively. All of the hazardous metals detected were below the recommended maximum standards of the Ministry of Food and Drug Safety. The mean amount of Pb detected in tattoo stickers for children was 0.24 ㎍/kg and Cd was not detected, meaning both metals met the recommended criteria. There was no statistically significant difference in all measured metals between children's tattoo stickers and adults' tattoo stickers. In the results of the study on the hazardous metal content of tattoo inks, four products (25%) for Pb, one product (6%) for As, 13 products (81%) for Ni, four products (25%) for Cu, and five products (31%) for Zn exceeded the recommended standards approved by the government. The highest predicted exposure amount for hazardous metals exceeding the recommended level of tattoo inks in a single tattooing was 5.69 ㎍/kg for Ni, 8.51 ㎍/kg for Zn, 0.44 ㎍/kg for Pb, 8.07 ㎍/kg for Cu, 0.44 ㎍/kg for As, and 71.36 ㎍/kg for Ba. Conclusions: It is necessary to prepare criteria for content limitation for the management of Co, Cr, Ba and Se tattoo cosmetics, and tattoo inks require thorough quality control.

A Case Study on the Development of Environment Friendly Citrus Farming in Jeju - Focusing on Graduate Farms of Korea National College of Agriculture and Fisheries (제주 친환경 감귤 농업 발전을 위한 사례연구 - 한농대 졸업생 농가를 중심으로 -)

  • Kang, S.K.;Kim, J.S.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.16 no.1
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    • pp.37-53
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    • 2014
  • The purpose of this research is to find what difficulties the agricultural successors, the Korea National College of Agriculture and Fisheries (KNCAF) graduates, face with in implementing eco-friendly agriculture in Jeju, and what solutions they can be provided with. This research, a case study on the basis of open-ended survey questions, has 6 cases out of 8 graduates who have or had implemented eco-friendly citrus farming. In Jeju, 24 graduates have involved in citrus farming. According to the case study, only one case was environment-friendly farming method at the pesticide-free level, and the others at organic farming level. All the cases have tried to alter main crops or to diversify management for coping with global climate change and market-opening. On analyzing operating cost to gain product of merchantable quality, it revealed that the environment-friendly farming method needs much more managing efforts than the conventional farming does. But to the contrary, the materials cost in the environment-friendly farming method was lower than in the conventional farming method. In the total production and the price, the environment-friendly farming was 20~50% lower and 10~50% higher than the conventional farming, respectively. Difficulties which the graduates confronted with in implementing the environment-friendly agriculture are as below. Firstly, many of the difficulties have resulted from lack of the environment-friendly farming techniques, and the high cost of farm scale improvement due to high price of land and topographical features of Jeju. Secondly, the agricultural successors, the KNCAF graduates, have trouble in obtaining approval of their parents to changeover from the conventional farming to the environment-friendly farming. Lastly, there is no advisory organizations and experts for environment-friendly farming in the given area. For shift to the environment-friendly farming, followings are needed. Agricultural Technology & Extension center, with cooperation of leading farms in environment-friendly farming, should have a key role in offering education and consults on the environment-friendly farming techniques. Also, this organization should inform rapidly the research results to the farmers, and their feed-back should be involved in the next research. Therefore, it is suggested that the forum called 'Environment-friendly Organic Farming Forum in Jeju' tentatively is organized.

Space design Effect on Marketing ­ - Concentrating on B to B transaction - (공간 디자인이 마케팅에 미치는 영향 ­ - 전문전시회에서 B to B 거래중심으로 -)

  • Kim, Young Soo;Jeong, Dong Bin;Kim, Kyong Hoon
    • Korea Science and Art Forum
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    • v.20
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    • pp.147-158
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    • 2015
  • This study made an approach to the industrial exhibition space, which is a medium of marketing communication, from the position of an enterprise and consumers through the output of Space Design, and conducted it with focus on B2B transactions among specialized exhibitions. In addition, this study inquired into what factors should be considered along with space design by interpreting the purpose of participating in the exhibition and space design of the enterprise which supply capital goods, elements, related technologies and materials, etc. This study aimed at drawing the direct/indirect effect, produced by space design, on the marketing by analyzing correlation between space design and participating enterprises' marketing. Despite the marketing effect of the exhibition, which was proved by preceding research results, the reality is that exhibition-participating expenses work as considerable burden on enterprises. Particularly, booth design, which is forming the most proportion among the participating expenses, was found to have insufficient influence on visitors due to the decline in its importance among diverse factors influencing visitor's decision to visit a booth. Regardless of the business category of participating enterprises in the exhibition, the standard of exhibits was ranked as the most important consideration factor in visiting a booth. Even by business category, the standard of booth design rarely had an influence on booth visit. Booth design had an affirmative influence on participating enterprise's preference, but its influence on product purchase or business talk & contact with a participating enterprise or price was found to be extremely low. It's difficult to judge marketing success or failure of an exhibition by the form and standard of booth design. Preferably, this study infers that it's necessary to put much weight on qualitative excellence of an exhibition, which consists of participation of an enterprise in possession of excellent technologies, exhibits with higher standards and high-quality visitors with purchasing power. This study suggests that it's more effective to set up the plan for expansion of participation in exhibition by optimally regulating the proportion of space design in participating expense to increase marketing effectiveness of an exhibition. The limitations of this study, analysis of which based on the visitors to an exhibition only, requires supplementation through the follow-up research work on participating enterprises in the exhibition.

Self-Esteem and Depression of the Elderly People Living Alone (독거노인의 자아존중감과 우울)

  • Kyung Hyun Suh;Young Sook Kim
    • Korean Journal of Culture and Social Issue
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    • v.9 no.1
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    • pp.115-137
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    • 2003
  • This study aims to investigate the related variables of self-esteem and depression among the Korean elderly people living alone and examine the relationships or interactions between those variables. Participants were 676 elderly men and women who were at least 65 years of age(M=76.17, sd=7.60) and lived in Seoul, Korea. Three hundred seventy eight participants of this study were living alone. Participants completed questionnaires and psychological tests including: Rosenberg's Self-Esteem Scale, Zung's Self-Rating Depression Scale, The Index of Activities of Daily Living(IADL), Social Support Index(SSI), and Life Satisfaction in the Elderly Scale(LSES). Main statistical designs were 2(gender)×2(residential types), Pearson-product moment and regression analysis. Results indicated that the elderly living alone recognized their health poorer, have lower economic status, and received less social supports than the elderly lived with others. The elderly men who had children were more likely to lived alone. And the elderly men living alone received less social supports than the elderly women living alone, and significant gender difference was found in the reason of living alone. The elderly men living alone had lower self-esteem than the elderly women living alone, while the elderly living alone showed more depressive symptoms than the elderly living with others. There were 2-way interactions both in self-esteem and depression by gender and residential types. There was highly significant gender difference in self-esteem only for the elderly living alone, and it was found that there was no significant difference in depression between elderly men living alone and women living with others. Regression analysis revealed that physical function and self-reported health are predictors of self-esteem, and physical function, self-reported health, and social support are predictors of depression for the Korean elderly living alone. These findings reiterate the role of physical function, social support, health in self-esteem and depession among the elderly and suggest the gender role for quality of life among the Korean elderly living alone.

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Studies on the Nitrogenous Utilization and Basal Metabolism of Korean Native Goat (한국(韓國) 재래산양(在來山羊)의 질소대사(窒素代謝) 및 기초대사량(基礎代謝量)에 관(關)한 연구(硏究))

  • Oh, Hong Rock
    • Korean Journal of Agricultural Science
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    • v.9 no.2
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    • pp.546-555
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    • 1982
  • To evaluate the digestibility and absorbability of proteins, and the rates of energy and nitrogen(N) metabolism of the Korean native goats, studies were carried out with open type respiration apparatus based on the nitrogen-carbon method. The results on the nitrogen retention and the metabolic rate of energy, which was obtained with one male (10-month-old) and one female (24-month-old) goats, both weighing ${\simeq}20kg$, are summarized as follows. 1. When the goats were fed ad libitum the medium quality orchard grass hay, they consumed hay about 0.66 to 0.92% of body weight per day. The hay intake was remained the same even when high quality hay was provided. This amount of hay intake was relatively lower than that of dairy goat and sheep. It was believed to be partly due to the change in feeding enviroment. When fed with hay and soybean meal together, the goats ate hay about 1.06% and soybean meal about 0.60% of body weight, corresponding to 1.66% of body weight as fed basis. 2. The $CO_2$ gas produced from the goat in the open type respiration chamber and absorbed with KOH solution was estimated to be 99~117g/day. The difference in feed intake did not influence the $CO_2$ production; however, these seems to be a linea relationship between body weight and $CO_2$ production. 3. When fed orchard grass hay only, the goats showed protein digestibility of 24~41%. The protein digestibility incresed to 58.2% when fed hay and soybean meal together. A negative nitrogen balance(-0.16g N/day) was observed with goats fed 11.53g N originated from 212g hay and 150g soybean meal. Converting that nitrogen ingested to a crude protein, the amount of crude protein intake by the goats per day was 77.9g compared to 40~45g N known to be required in a day by goat weighing 20kg, indicating that the extra protein ingested was metabolized to provide energy. 4. When the male and female goats comsumed 624 kcal gross energy and 824 kcal gross energy by consuming 158g and 213g of hay, respectively, the digestible energy intake was calculated to be 260kcal for the male and 199kcal for the female goat. The daily heat production of male and female goats were 338kcal and 334kcal, respectively, when fed hay only. However, the female goat fed 212g hay and 150g soybean meal produced about 591kcal per day. Consequently, the energy requirment of the Korean native goats weighing ${\simeq}20kg$ was concluded to be $${\geq_-}$$600kcal net energy per day. 5. The fasting heat product ion of a male goat weighing 27.7kg was 412kcal per day when fasted for 2~3 days. When fasted for 3~4 days, the value decresed to 240kcal. The enviromental temperatures during the expreimental period were ranged from 19 to $34.5^{\circ}C$. The goats seemed to be panting when the chamber temperature rose to $32^{\circ}C$ or above. 6. When fed low levels of dietary protein, serum protein levels of the goats were decresed slightly ($${\leq_-}$$10%); however, urea content in the serum was observed to decrese to a great extent (3X).

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Assessing the Damage: An Exploratory Examination of Electronic Word of Mouth (손해평고(损害评估): 대전자구비행소적탐색성고찰(对电子口碑行销的探索性考察))

  • Funches, Venessa Martin;Foxx, William;Park, Eun-Joo;Kim, Eun-Young
    • Journal of Global Scholars of Marketing Science
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    • v.20 no.2
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    • pp.188-198
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    • 2010
  • This study attempts to examine the influence that negative WOM (NWOM) has in an online context. It specifically focuses on the impact of the service failure description and the perceived intention of the communication provider on consumer evaluations of firm competence, attitude toward the firm, positive word of mouth and behavioral intentions. Studies of communication persuasiveness focus on "who says what; to whom; in which channel; with what effect (Chiu 2007)." In this research study, we examine electronic web posting, particularly focusing on two aspects of "what": the level of service failure communicated and perceived intention of the individual posting. It stands to reason electronic NWOM that appears to be trying to damage a product’s or firm's reputation will be viewed as more biased and will thus be considered as less credible. According to attribution theory, people search for the causes of events especially those that are negative and unexpected (Weiner 2006). Hennig-Thurau and Walsh (2003) state "since the reader has only limited knowledge and trust of the author of an online articulation the quality of the contribution could be expected to serve as a potent moderator of the articulation-behavior relationship. We therefore posit the following hypotheses: H1. Subjects exposed to electronic NWOM describing a high level of service failure will provide lower scores on measures of (a) firm competence, (b) attitude toward the firm, (c) positive word of mouth, and (d) behavioral intention than will subjects exposed to electronic NWOM describing a low level of service failure. H2. Subjects exposed to electronic NWOM with a warning intent will provide lower scores on measures of (a) firm competence, (b) attitude toward the firm, (c) positive word of mouth, and (d) behavioral intention than will subjects exposed to electronic NWOM with a vengeful intent. H3. Level of service failure in electronic NWOM will interact with the perceived intention of the electronic NWOM, such that there will be a decrease in mean response on measures of (a) firm competence, (b) attitude toward the firm, (c) positive word of mouth, and (d) behavioral intention from electronic NWOM with a warning intent to a vengeful intent. The main study involved a2 (service failure severity) x2 (NWOM with warning versus vengeful intent) factorial experiment. Stimuli were presented to subjects online using a mock online web posting. The scenario described a service failure associated with non-acceptance of a gift card in a brick-and-mortar retail establishment. A national sample was recruited through an online research firm. A total of 113 subjects participated in the study. A total of 104 surveys were analyzed. The scenario was perceived to be realistic with 92.3% giving the scenario a greater than average response. Manipulations were satisfactory. Measures were pre-tested and validated. Items were analyzed and found reliable and valid. MANOVA results found the multivariate interaction was not significant, allowing our interpretation to proceed to the main effects. Significant main effects were found for post intent and service failure severity. The post intent main effect was attributable to attitude toward the firm, positive word of mouth and behavioral intention. The service failure severity main effect was attributable to all four dependent variables: firm competence, attitude toward the firm, positive word of mouth and behavioral intention. Specifically, firm competence for electronic NWOM describing high severity of service failure was lower than electronic NWOM describing low severity of service failure. Attitude toward the firm for electronic NWOM describing high severity of service failure was lower than electronic NWOM describing low severity of service failure. Positive word of mouth for electronic NWOM describing high severity of service failure was lower than electronic NWOM describing low severity of service failure. Behavioral intention for electronic NWOM describing high severity of service failure was lower for electronic NWOM describing low severity of service failure. Therefore, H1a, H1b, H1c and H1d were all supported. In addition, attitude toward the firm for electronic NWOM with a warning intent was lower than electronic NWOM with a vengeful intent. Positive word of mouth for electronic NWOM with a warning intent was lower than electronic NWOM with a vengeful intent. Behavioral intention for electronic NWOM with a warning intent was lower than electronic NWOM with a vengeful intent. Thus, H2b, H2c and H2d were supported. However, H2a was not supported though results were in the hypothesized direction. Otherwise, there was no significant multivariate service failure severity by post intent interaction, nor was there a significant univariate service failure severity by post intent interaction for any of the three hypothesized variables. Thus, H3 was not supported for any of the four hypothesized variables. This study has research and managerial implications. The findings of this study support prior research that service failure severity impacts consumer perceptions, attitude, positive word of mouth and behavioral intentions (Weun et al. 2004). Of further relevance, this response is evidenced in the online context, suggesting the need for firms to engage in serious focused service recovery efforts. With respect to perceived intention of electronic NWOM, the findings support prior research suggesting reader's attributions of the intentions of a source influence the strength of its impact on perceptions, attitude, positive word of mouth and behavioral intentions. The implication for managers suggests while consumers do find online communications to be credible and influential, not all communications are weighted the same. A benefit of electronic WOM, even when it may be potentially damaging, is it can be monitored for potential problems and additionally offers the possibility of redress.

The Mediating Effect of Experiential Value on Customers' Perceived Value of Digital Content: China's Anti-virus Program Market (경험개치대소비자대전자내용적인지개치적중개영향(经验价值对消费者对电子内容的认知价值的中介影响): 중국살독연건시장(中国杀毒软件市场))

  • Jia, Weiwei;Kim, Sae-Bum
    • Journal of Global Scholars of Marketing Science
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    • v.20 no.2
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    • pp.219-230
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    • 2010
  • Digital content makes big changes to our daily lives while bringing opportunities and challenges for companies. Creative firms integrate pictures, texts, videos, audios, and data by digitalization to develop new products or services and create digital experiences to promote their brands. Most articles on digital content contribute to the basic concept or development of marketing it in literature. Actually, compared with traditional value chains for common products or services, the digital content industry seems to have more potential value. Because quite a bit of digital content is free to the consumer, price is not necessarily perceived as an indicator of the quality or value of information (Rowley 2008). It becomes evident that a current theme in digital content is the issue of "value," and research on customers' perceived value of digital content is a necessity. This article argues that experiential value has an advantage in customers' evaluations of digital content. Two different but related contributions to the understanding of "value" of digital content are made here. First, based on the comparison of digital content with products and services, the article proposes two key characteristics that make experiential strategy available for digital content: intangibility and near-zero reproduction cost. On top of that, based on the discussion of the gap between company's idealized value and customer's perceived value, this article emphasizes that digital content prices and pricing of digital content is different from products and services. As a result of intangibility, prices may not reflect customer value. Moreover, the cost of digital content in the development stage may be very high while reproduction costs shrink dramatically. Moreover, because of the value gap mentioned before, the pricing polices vary for different digital contents. For example, flat price policy is generally used for movies and music (Magiera 2001; Netherby 2002), while for continuous demand, digital content such as online games and anti-virus programs involves a more complicated matter of utility and competitive price levels. Digital content companies have to explore various kinds of strategies to overcome this gap. Rethinking marketing solutions such as advertisements, images, and word-of-mouth and their effect on customers' perceived value becomes essential. China's digital content industry is becoming more and more globalized and drawing special attention from different countries and regions that have respective competitive advantages. The 2008-2009 Annual Report on the Development of China's Digital Content Industry (CCIDConsulting 2009) indicates that, with the driven power of domestic demand and governmental policy support, the country's digital content industry maintained a fast growth of some 30 percent in 2008, obviously indicating the initial stage of industry expansion. In China, anti-virus programs and other software programs which need to be updated use a quarter-based pricing policy. Customers can download a trial version for free and use it for six months or a year. If they want to use it longer, continuous payment is needed. They examine the excellence of the digital content during this trial period and decide whether to pay for continued usage. For China’s music and movie industries, as a result of initial development, experiential strategy has not been much applied, even though firms in other countries find the trial experience and explore important strategies(such as customers listening to music for several seconds for free before downloading it). For the above reasons, anti-virus program may be a representative for digital content industry in China and an exploratory study of the advantage of experiential value in customer's perceived value of digital content is done in the anti-virus market of China. In order to enhance the reliability of the survey data, this study focused on people who were experienced users of anti-virus programs. The empirical results revealed that experiential value has a positive effect on customers' perceived value of digital content. In other words, because digital content is intangible and the reproduction costs are nearly zero, customers' evaluations are based heavily on their experience. Moreover, image and word-of-mouth do not have a positive effect on perceived value, only on experiential value. That is to say, a digital content value chain is different from that of a general product or service. Experiential value has a notable advantage and mediates the effect of image and word-of-mouth on perceived value. The results of this study help provide an understanding of why free digital content downloads exist in developing countries. Customers can perceive the value of digital content only by using and experiencing it. This is also why such governments support the development of digital content. Other developing countries whose digital content business is also in the beginning stage can make use of the suggestions here. Moreover, based on the advantage of experiential strategy, companies should make more of an effort to invest in customers' experience. As a result of the characteristics and value gap of digital content, customers perceive more value in the intangible digital content only by experiencing what they really want. Moreover, because of the near-zero reproduction costs, companies can perhaps use experiential strategy to enhance customer understanding of digital content.

Effects of Light Intensity, Nutrient Solution Compositions before Harvest and the Time of Nutrient Solution Removal on Nitrate Contents in Hydroponically-Grown Leaf Lettuces in Closed Plant Production System (폐쇄형 식물생산시스템에서 광도, 수확 전 양액조성 및 양액결제시기가 잎상추의 체내 질산염 함량에 미치는 영향)

  • Yeo, Kyung-Hwan;Choi, Gyeong-Lee;Lee, Jung-Sup;Lee, Jae-Han;Park, Kyoung-Sub;Kim, Jin-Hyun
    • Journal of Bio-Environment Control
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    • v.26 no.4
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    • pp.393-401
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    • 2017
  • The nitrate ($NO_3{^-}$) accumulation of hydroponically grown leafy vegetables may increase in the condition of a closed-type plant production system with low light intensity due to low activity of enzymes involved in nitrogen assimilation and the use of $NO_3-N$ as major nitrogen source. The objective of this study is to investigate the effects of light intensities, nutrient solution compositions and the time of nutrient solution removal before harvest on nitrate contents of hydroponically-grown lettuces in a closed plant production system. The reduction of nitrate contents in leafy lettuces 'Cheongchima' was higher in the treatments of 'TW' (nutrient solution removal) and '$(NH_4)_2CO_3$' (use of ammonium carbonate as nitrogen source) than those in other treatments, which significantly lowered fresh weight and leaf area of the plants. In the light intensity of $100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, the nitrate content was effectively reduced without causing any growth retardation, by substitution of the nutrient solution composition that $NO_3-N$ was removed ('$NO_3-N$ removal' treatment) or the half strength of standard nutrient solution was applied ('1/2 S' treatment), for 7days before harvest. The effects of light intensity and the time of nutrient solution removal before harvest on growth and nitrate contents in leafy lettuces were investigated. The nitrate contents in leaves under the light condition of $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ before nutrient solution removal were lower than those of 100 or $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. The removal of nutrient solution for 7 days before harvest quickly reduced the amount of nitrates in leaves in all the light intensities with a greater degree under the $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ of light condition, while the 7 days-removal with both 200 and $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ of light conditions caused decrease in 16~31% of leaf area and 20~35% of fresh weight, compared to the 3 days-removal treatment. The nitrate contents were greatly reduced from 3,018 to 1,035 in $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, and 2,021 to 480 ppm in the light condition of $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, with the nutrient solution removal for 3 days before harvest, without causing any deterioration in growth and product quality. The vitamin C contents in leaves were higher in the treatment of nutrient solution removal for both 3 and 5 days before harvest with the light condition of $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ than those in the light condition of 100 or $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$.