• 한국수산과학회지
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• 제17권5호
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• pp.449-470
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• 1984

서해안 금강하구의 내초도에서 1980년 7월부터 1983년 10월까지 맛조개(Solen strictus)의 생식소에 기생한 Bacciger 속 cercaria의 생활사를 구명하고자 sporocyst 및 cercaria의 형태와 발육과정, 기생률을 조사하였다. 또한 제이중간숙주 및 종숙주를 실험실에서 인공감염실험과 함께 내초도자연환경구에서 조사하여 metacercaria와 성충의 발육과정을 조사 연구한 결과 지금까지 밝혀진바 없는 Bacciger harengulae의 생활사가 구명되었다. Bacciger harengulae는 맛조개, 대합, 바지락, 띠조개가 제일중간숙주이고, 밀새우를 제이중간숙주로 하며, 종숙주는 전어, 밴댕이로 밝혀졌다. 맛조개의 생식소에 기생된 성숙한 sporocyst의 크기는 $4.0{\sim}4.3{\times}0.20{\sim}0.21$ mm이고, cercaria는 체부 $270{\times}147{\mu}m$, 미부 $270{\times}147{\mu}m$의 크기로서 꼬리 양측에 27쌍의 강모속과 1개의 강미속은 6본의 가닥으로 되어있다. cercaria의 체내에는 구흡반($52{\times}42{\mu}m$), 인두($32{\times}25{\mu}m$), 복흡반($52{\times}50{\mu}m$)과 2 개의 정소와 V자형의 배설낭이 뚜렷이 나타나며, 화염세포식은 2[(3+3)+(3+3)]=24이다. 3년에 걸쳐 맛조개에 기생하고 있는 cercaria의 평균 기생률은 $9.67\%$ 였는데, 이것은 수온의 변화와는 관계없이 연중기생된다. 기생률이 가장 높은 시기는 수온 $28.8^{\circ}C$인 7월($28.0\%$)이고, 가장 낮은 시기는 수온 $19.5^{\circ}C$인 10월($2.4\%$)이었다. 맛조개의 cercaria 기생률은 각장이 클수록 높았으며, 4.0cm 이하에서는 cercaria가 검출되지 않았다. cercaria가 성숙되는 시기는 년중 수온이 $19.5^{\circ}C$이상 상승하는 $5{\sim}10$월까지며, 수온 $19.5^{\circ}C$이하가 되면 미숙한 cercaria만이 검출된다. Cercaria는 수온 $20^{\circ}C$에서 35시간, $25^{\circ}C$에서는 29시간까지 활력이 있었으며, 생존시간은 각각 71시간, 34시간이었으나 $20^{\circ}C$이하에서는 운동력이 활발하지 못하였다. 맛조개에서 유출된 cercaria를 밀새우에 감염시킨 결과 2{\sim}3시간후에 근육에 기생하였고, 기생한 cercaria는 $7{\sim}8$시간후에 cyst를 형성하였으며, 15일이 경과되어 $420{\times}310{\mu}m$의 성숙한 metacercaria로 발육되었다. 실험실에서 수온 $20^{\circ}C$일때 밀새우의 metacercaria 감염률은 $17.0\%$ 이었고, $25^{\circ}C$때는 $61.0\%$의 높은 감염률을 나타냈으며, 감염된 부위는 제일복절, 두흉부, 제이, 삼, 오복절의 순으로 감염되었다. 내초도의 자연 서식장산 밀새우의 metacercaria 감염률은 수온 $26.5^{\circ}C$인 6월에 $9.6{\sim}11.11\%$, 수온 $28{\sim}29.5^{\circ}C$인 7,8월에는 $1.56{\sim}2.50\%$의 감염률을 나타냈다. metacercaria가 감염된 밀새우를 사육중인 전어에 먹인 결과, 20일후 전어의 장에서 $440{\sim}520{\times}310{\sim}360{\mu}m$의 성충으로 발육되었고, 성숙한 충난은 $20{\sim}24{\times}11{\sim}20{\mu}m$ 크기의 타원형이었다. 실험실에서 검출한 것과 동일한 성충이 내초도의 자연산 전어, 밴댕이에서도 체장과 관계없이 $87.3{\sim}100\%$(평균 $95.2\%$) 검출되었으며, 6, 7월에는 $100\%$ 검출되나, 8, 10월에는 $87.3{\sim}88.9\%$로 그 검출률이 낮아졌다. 전어에서 발육된 성충의 크기와 내부형태를 Yamaguti(1938)가 밴댕이에서 검출한 것과 비교한바, 동일하므로 이 흡충을 Bacciger harengulae로 동정하였다.

• 마케팅과학연구
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• 제18권3호
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• pp.59-88
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• 2008

Digital Convergence means integration between industry, technology, and contents, and in marketing, it usually comes with creation of new types of product and service under the base of digital technology as digitalization progress in electro-communication industries including telecommunication, home appliance, and computer industries. One can see digital convergence not only in instruments such as PC, AV appliances, cellular phone, but also in contents, network, service that are required in production, modification, distribution, re-production of information. Convergence in contents started around 1990. Convergence in network and service begins as broadcasting and telecommunication integrates and DMB(digital multimedia broadcasting), born in May, 2005 is the symbolic icon in this trend. There are some positive and negative expectations about DMB. The reason why two opposite expectations exist is that DMB does not come out from customer's need but from technology development. Therefore, customers might have hard time to interpret the real meaning of DMB. Time is quite critical to a high tech product, like DMB because another product with same function from different technology can replace the existing product within short period of time. If DMB does not positioning well to customer's mind quickly, another products like Wibro, IPTV, or HSPDA could replace it before it even spreads out. Therefore, positioning strategy is critical for success of DMB product. To make correct positioning strategy, one needs to understand how consumer interprets DMB and how consumer's interpretation can be changed via communication strategy. In this study, we try to investigate how consumer perceives a new product, like DMB and how AD strategy change consumer's perception. More specifically, the paper segment consumers into sub-groups based on their DMB perceptions and compare their characteristics in order to understand how they perceive DMB. And, expose them different printed ADs that have messages guiding consumer think DMB in specific ways, either cellular phone or personal TV. Research Question 1: Segment consumers according to perceptions about DMB and compare characteristics of segmentations. Research Question 2: Compare perceptions about DMB after AD that induces categorization of DMB in direction for each segment. If one understand and predict a direction in which consumer perceive a new product, firm can select target customers easily. We segment consumers according to their perception and analyze characteristics in order to find some variables that can influence perceptions, like prior experience, usage, or habit. And then, marketing people can use this variables to identify target customers and predict their perceptions. If one knows how customer's perception is changed via AD message, communication strategy could be constructed properly. Specially, information from segmented customers helps to develop efficient AD strategy for segment who has prior perception. Research framework consists of two measurements and one treatment, O1 X O2. First observation is for collecting information about consumer's perception and their characteristics. Based on first observation, the paper segment consumers into two groups, one group perceives DMB similar to Cellular phone and the other group perceives DMB similar to TV. And compare characteristics of two segments in order to find reason why they perceive DMB differently. Next, we expose two kinds of AD to subjects. One AD describes DMB as Cellular phone and the other Ad describes DMB as personal TV. When two ADs are exposed to subjects, consumers don't know their prior perception of DMB, in other words, which subject belongs 'similar-to-Cellular phone' segment or 'similar-to-TV' segment? However, we analyze the AD's effect differently for each segment. In research design, final observation is for investigating AD effect. Perception before AD is compared with perception after AD. Comparisons are made for each segment and for each AD. For the segment who perceives DMB similar to TV, AD that describes DMB as cellular phone could change the prior perception. And AD that describes DMB as personal TV, could enforce the prior perception. For data collection, subjects are selected from undergraduate students because they have basic knowledge about most digital equipments and have open attitude about a new product and media. Total number of subjects is 240. In order to measure perception about DMB, we use indirect measurement, comparison with other similar digital products. To select similar digital products, we pre-survey students and then finally select PDA, Car-TV, Cellular Phone, MP3 player, TV, and PSP. Quasi experiment is done at several classes under instructor's allowance. After brief introduction, prior knowledge, awareness, and usage about DMB as well as other digital instruments is asked and their similarities and perceived characteristics are measured. And then, two kinds of manipulated color-printed AD are distributed and similarities and perceived characteristics for DMB are re-measured. Finally purchase intension, AD attitude, manipulation check, and demographic variables are asked. Subjects are given small gift for participation. Stimuli are color-printed advertising. Their actual size is A4 and made after several pre-test from AD professionals and students. As results, consumers are segmented into two subgroups based on their perceptions of DMB. Similarity measure between DMB and cellular phone and similarity measure between DMB and TV are used to classify consumers. If subject whose first measure is less than the second measure, she is classified into segment A and segment A is characterized as they perceive DMB like TV. Otherwise, they are classified as segment B, who perceives DMB like cellular phone. Discriminant analysis on these groups with their characteristics of usage and attitude shows that Segment A knows much about DMB and uses a lot of digital instrument. Segment B, who thinks DMB as cellular phone doesn't know well about DMB and not familiar with other digital instruments. So, consumers with higher knowledge perceive DMB similar to TV because launching DMB advertising lead consumer think DMB as TV. Consumers with less interest on digital products don't know well about DMB AD and then think DMB as cellular phone. In order to investigate perceptions of DMB as well as other digital instruments, we apply Proxscal analysis, Multidimensional Scaling technique at SPSS statistical package. At first step, subjects are presented 21 pairs of 7 digital instruments and evaluate similarity judgments on 7 point scale. And for each segment, their similarity judgments are averaged and similarity matrix is made. Secondly, Proxscal analysis of segment A and B are done. At third stage, get similarity judgment between DMB and other digital instruments after AD exposure. Lastly, similarity judgments of group A-1, A-2, B-1, and B-2 are named as 'after DMB' and put them into matrix made at the first stage. Then apply Proxscal analysis on these matrixes and check the positional difference of DMB and after DMB. The results show that map of segment A, who perceives DMB similar as TV, shows that DMB position closer to TV than to Cellular phone as expected. Map of segment B, who perceive DMB similar as cellular phone shows that DMB position closer to Cellular phone than to TV as expected. Stress value and R-square is acceptable. And, change results after stimuli, manipulated Advertising show that AD makes DMB perception bent toward Cellular phone when Cellular phone-like AD is exposed, and that DMB positioning move towards Car-TV which is more personalized one when TV-like AD is exposed. It is true for both segment, A and B, consistently. Furthermore, the paper apply correspondence analysis to the same data and find almost the same results. The paper answers two main research questions. The first one is that perception about a new product is made mainly from prior experience. And the second one is that AD is effective in changing and enforcing perception. In addition to above, we extend perception change to purchase intention. Purchase intention is high when AD enforces original perception. AD that shows DMB like TV makes worst intention. This paper has limitations and issues to be pursed in near future. Methodologically, current methodology can't provide statistical test on the perceptual change, since classical MDS models, like Proxscal and correspondence analysis are not probability models. So, a new probability MDS model for testing hypothesis about configuration needs to be developed. Next, advertising message needs to be developed more rigorously from theoretical and managerial perspective. Also experimental procedure could be improved for more realistic data collection. For example, web-based experiment and real product stimuli and multimedia presentation could be employed. Or, one can display products together in simulated shop. In addition, demand and social desirability threats of internal validity could influence on the results. In order to handle the threats, results of the model-intended advertising and other "pseudo" advertising could be compared. Furthermore, one can try various level of innovativeness in order to check whether it make any different results (cf. Moon 2006). In addition, if one can create hypothetical product that is really innovative and new for research, it helps to make a vacant impression status and then to study how to form impression in more rigorous way.