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Overcoming taxonomic challenges in DNA barcoding for improvement of identification and preservation of clariid catfish species

  • Piangjai Chalermwong;Thitipong Panthum;Pish Wattanadilokcahtkun;Nattakan Ariyaraphong;Thanyapat Thong;Phanitada Srikampa;Worapong Singchat;Syed Farhan Ahmad;Kantika Noito;Ryan Rasoarahona;Artem Lisachov;Hina Ali;Ekaphan Kraichak;Narongrit Muangmai;Satid Chatchaiphan6;Kednapat Sriphairoj;Sittichai Hatachote;Aingorn Chaiyes;Chatchawan Jantasuriyarat;Visarut Chailertlit;Warong Suksavate;Jumaporn Sonongbua;Witsanu Srimai;Sunchai Payungporn;Kyudong Han;Agostinho Antunes;Prapansak Srisapoome;Akihiko Koga;Prateep Duengkae;Yoichi Matsuda;Uthairat Na-Nakorn;Kornsorn Srikulnath
    • Genomics & Informatics
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    • v.21 no.3
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    • pp.39.1-39.15
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    • 2023
  • DNA barcoding without assessing reliability and validity causes taxonomic errors of species identification, which is responsible for disruptions of their conservation and aquaculture industry. Although DNA barcoding facilitates molecular identification and phylogenetic analysis of species, its availability in clariid catfish lineage remains uncertain. In this study, DNA barcoding was developed and validated for clariid catfish. 2,970 barcode sequences from mitochondrial cytochrome c oxidase I (COI) and cytochrome b (Cytb) genes and D-loop sequences were analyzed for 37 clariid catfish species. The highest intraspecific nearest neighbor distances were 85.47%, 98.03%, and 89.10% for COI, Cytb, and D-loop sequences, respectively. This suggests that the Cytb gene is the most appropriate for identifying clariid catfish and can serve as a standard region for DNA barcoding. A positive barcoding gap between interspecific and intraspecific sequence divergence was observed in the Cytb dataset but not in the COI and D-loop datasets. Intraspecific variation was typically less than 4.4%, whereas interspecific variation was generally more than 66.9%. However, a species complex was detected in walking catfish and significant intraspecific sequence divergence was observed in North African catfish. These findings suggest the need to focus on developing a DNA barcoding system for classifying clariid catfish properly and to validate its efficacy for a wider range of clariid catfish. With an enriched database of multiple sequences from a target species and its genus, species identification can be more accurate and biodiversity assessment of the species can be facilitated.

Perception and Trust of Korean Society and People among Adolescents and their Parents: Indigenous Psychological Analysis (청소년과 성인 세대의 한국 사회와 사람에 대한 인식 및 신뢰 )

  • Young-Shin Park ;Uichol Kim
    • Korean Journal of Culture and Social Issue
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    • v.11 no.3
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    • pp.91-119
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    • 2005
  • This study examines the perception and trust of Korean society and people among students and adults using the indigenous psychological analysis. A matched sample of 1,107 participants, consisting of 369 students, their mothers and their fathers completed a questionnaire developed by the present researchers. The results indicate that parents more likely than adolescents to hold negative views of Korean society. Adults are more likely than adolescents to view Korean society as showing high ingroup favoritism, to be insecure, to be conservative, to be corrupt, and to have social inequities. Both groups agree that Korean society is not rational nor democratic, but believe that it has the potential for progress. Second, parents are more likely to hold negative views about Korean people. Adults are more likely than adolescents of viewing Korean people as overly conscious about social face, emotional, selfish, exclusionary, and conceited. Both adolescents and their parents agree that Koreans are cooperative, full of jung (deep affection and attachment), and sincere. Third, adults are less likely to trust Korean institutions than adolescents. Adults are less likely than adolescents to trust National Assembly, political parties, and unions. Adolescents are more likely than their parents to trust family members, school friends, teachers, and government employees. These results indicate that adolescents have higher trust of Korean society and people than their parents. Fifth, the overall results indicate that both group perceive Korean society as showing high ingroup favoritism and corruption. In terms of Korean people, respondents had a more balanced view of perceiving them as highly sensitive to social face and being emotional, while also perceiving them as cooperative and full of jung. The trust of Korean institutions were generally low, especially the National Assembly and political parties. However, the trust of family was very high, followed by trust of school friends and teachers. The trust of government employees was low and this was especially the case for politicians.

Unenhanced Breast MRI With Diffusion-Weighted Imaging for Breast Cancer Detection: Effects of Training on Performance and Agreement of Subspecialty Radiologists

  • Yeon Soo Kim;Su Hyun Lee;Soo-Yeon Kim;Eun Sil Kim;Ah Reum Park;Jung Min Chang;Vivian Youngjean Park;Jung Hyun Yoon;Bong Joo Kang;Bo La Yun;Tae Hee Kim;Eun Sook Ko;A Jung Chu;Jin You Kim;Inyoung Youn;Eun Young Chae;Woo Jung Choi;Hee Jeong Kim;Soo Hee Kang;Su Min Ha;Woo Kyung Moon
    • Korean Journal of Radiology
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    • v.25 no.1
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    • pp.11-23
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    • 2024
  • Objective: To investigate whether reader training improves the performance and agreement of radiologists in interpreting unenhanced breast magnetic resonance imaging (MRI) scans using diffusion-weighted imaging (DWI). Materials and Methods: A study of 96 breasts (35 cancers, 24 benign, and 37 negative) in 48 asymptomatic women was performed between June 2019 and October 2020. High-resolution DWI with b-values of 0, 800, and 1200 sec/mm2 was performed using a 3.0-T system. Sixteen breast radiologists independently reviewed the DWI, apparent diffusion coefficient maps, and T1-weighted MRI scans and recorded the Breast Imaging Reporting and Data System (BI-RADS) category for each breast. After a 2-h training session and a 5-month washout period, they re-evaluated the BI-RADS categories. A BI-RADS category of 4 (lesions with at least two suspicious criteria) or 5 (more than two suspicious criteria) was considered positive. The per-breast diagnostic performance of each reader was compared between the first and second reviews. Inter-reader agreement was evaluated using a multi-rater κ analysis and intraclass correlation coefficient (ICC). Results: Before training, the mean sensitivity, specificity, and accuracy of the 16 readers were 70.7% (95% confidence interval [CI]: 59.4-79.9), 90.8% (95% CI: 85.6-94.2), and 83.5% (95% CI: 78.6-87.4), respectively. After training, significant improvements in specificity (95.2%; 95% CI: 90.8-97.5; P = 0.001) and accuracy (85.9%; 95% CI: 80.9-89.8; P = 0.01) were observed, but no difference in sensitivity (69.8%; 95% CI: 58.1-79.4; P = 0.58) was observed. Regarding inter-reader agreement, the κ values were 0.57 (95% CI: 0.52-0.63) before training and 0.68 (95% CI: 0.62-0.74) after training, with a difference of 0.11 (95% CI: 0.02-0.18; P = 0.01). The ICC was 0.73 (95% CI: 0.69-0.74) before training and 0.79 (95% CI: 0.76-0.80) after training (P = 0.002). Conclusion: Brief reader training improved the performance and agreement of interpretations by breast radiologists using unenhanced MRI with DWI.

A Study on Web-based Technology Valuation System (웹기반 지능형 기술가치평가 시스템에 관한 연구)

  • Sung, Tae-Eung;Jun, Seung-Pyo;Kim, Sang-Gook;Park, Hyun-Woo
    • Journal of Intelligence and Information Systems
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    • v.23 no.1
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    • pp.23-46
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    • 2017
  • Although there have been cases of evaluating the value of specific companies or projects which have centralized on developed countries in North America and Europe from the early 2000s, the system and methodology for estimating the economic value of individual technologies or patents has been activated on and on. Of course, there exist several online systems that qualitatively evaluate the technology's grade or the patent rating of the technology to be evaluated, as in 'KTRS' of the KIBO and 'SMART 3.1' of the Korea Invention Promotion Association. However, a web-based technology valuation system, referred to as 'STAR-Value system' that calculates the quantitative values of the subject technology for various purposes such as business feasibility analysis, investment attraction, tax/litigation, etc., has been officially opened and recently spreading. In this study, we introduce the type of methodology and evaluation model, reference information supporting these theories, and how database associated are utilized, focusing various modules and frameworks embedded in STAR-Value system. In particular, there are six valuation methods, including the discounted cash flow method (DCF), which is a representative one based on the income approach that anticipates future economic income to be valued at present, and the relief-from-royalty method, which calculates the present value of royalties' where we consider the contribution of the subject technology towards the business value created as the royalty rate. We look at how models and related support information (technology life, corporate (business) financial information, discount rate, industrial technology factors, etc.) can be used and linked in a intelligent manner. Based on the classification of information such as International Patent Classification (IPC) or Korea Standard Industry Classification (KSIC) for technology to be evaluated, the STAR-Value system automatically returns meta data such as technology cycle time (TCT), sales growth rate and profitability data of similar company or industry sector, weighted average cost of capital (WACC), indices of industrial technology factors, etc., and apply adjustment factors to them, so that the result of technology value calculation has high reliability and objectivity. Furthermore, if the information on the potential market size of the target technology and the market share of the commercialization subject refers to data-driven information, or if the estimated value range of similar technologies by industry sector is provided from the evaluation cases which are already completed and accumulated in database, the STAR-Value is anticipated that it will enable to present highly accurate value range in real time by intelligently linking various support modules. Including the explanation of the various valuation models and relevant primary variables as presented in this paper, the STAR-Value system intends to utilize more systematically and in a data-driven way by supporting the optimal model selection guideline module, intelligent technology value range reasoning module, and similar company selection based market share prediction module, etc. In addition, the research on the development and intelligence of the web-based STAR-Value system is significant in that it widely spread the web-based system that can be used in the validation and application to practices of the theoretical feasibility of the technology valuation field, and it is expected that it could be utilized in various fields of technology commercialization.

On the wing venation and scales of Dendrolimus spectabilis Butler (I) (솔나방의 시맥(翅脈)과 인편(鱗片)에 관(關)한 연구(硏究) (I))

  • Yun, Jeong Koo
    • Journal of Korean Society of Forest Science
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    • v.2 no.1
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    • pp.59-65
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    • 1962
  • The objects of this experiment are to find out the local variation of the Dendrolimus Spectabilis Butler, of which sample was first collecteted 15 bodies of male and 35 bodies of female adult at Suwon area. the wing veins and the scale shape have been observed through the microscope (100) and the scale size (from the bottom of the scale to the top of the lobe) has also been measured by the micrometer. The results of this experiment are as follows: 1. There is nodifference between the venation of the male body and that of the female body. Also we can not find any differences between the right and the left wing, and between each body. The fore wings consit of 13 longitudinal veins and the only one "V" shape cross vein which is between the 5th and 6th vein. The hind wings consist of 9 longitudinal veins and the only one "V" shape cross vein which is mentioned above. 2. The scale types are divided into 4 Groups in its shape. (A) The scales of I Group are short and the lower parts of them almost look like a circle, having a small projection at their bottom. The upper parts of them have 2 or 10 lobes. We can find the lobes with fine hairs or the lobes without them at the top of the scales. (B) The scales of II Group are longer than that of I Group. The shape of the lower parts of the scales is similar to that of I Group. The upper parts of the scales have 2 or 10 lobes. (C) The scales of III Group are long and almost alike in a long wedgeshape. The upper parts of the scales have 2 Or IO lobes and we can find long fine hairs at the top of each lobe. (D) The scales of IV Group are long and the shape of the lower parts of the scales is similar to that of III Group. The lobes are short and not sharp. We can find 2 or 9 lobes. 3. The scales of I Group and II Group are distributed on the whole surface except on the outer margin. The most scales of III Group are distributed on the wing base. The scales of IV Group are distributed on the outer margin only. The scales with 4 or 5 lobes are most widely distributed not considering their Group or distributing parts. 4. In I Group the variation of the scale length become gradually greater as the number of the lobes are increasing. In II, III, IV Group, however, the variation of the scale length is in direct opposition to the above mentioned. The variation of the scale width becomes pretty small in any Groups and the scale width become wider as the number of the lobes are increasing. 5. The source of the wing colouration is pigmnetal colour, and the wing colouration is expressed by the amount of brown and white scales.

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Evaluation of Korean Native Ducks on Production Efficiency Factor, Carcass Yield, Partial Meat Ratio and Meat Quality with Weeks (토종오리 대형종의 주령별 생산지수, 도체 수율, 부분육 비율 및 육질 평가)

  • Heo, Kang-Nyeong;Kim, Hak-Kyu;Kim, Chong-Dae;Kim, Sang-Ho;Lee, Myeong-Ji;Choo, Hyo-Jun;Son, Bo-Ram;Choi, Hee-Cheol;Lee, Sang-Bae;Hong, Eui-Chul
    • Korean Journal of Poultry Science
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    • v.40 no.2
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    • pp.121-127
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    • 2013
  • This work was carried to evaluate production efficiency factor, carcass yield and meat quality with weeks of Large-type Korean native ducks. Korean native ducks (n = 90) from National Institute of Animal Science (RDA, Korea) were used in this work. Ninety ducks were divided into 6 groups (15 birds/group) and were fed with meat-type duck diets for 8 wk old. When ducks grew at specific wk (6, 7 and 8 weeks), 2 ducks per group were slaughtered at 6, 7 and 8 wk old. Production efficiency factor, carcass yield, partial meat and meat quality were researched in this work. There was no significant difference on livability with weeks, but body weight at 7 and 8 wk old was higher than that at 6 wk old (P<0.05). Feed conversion ratio at 6, 7 and 8 wk old were 2.25, 2.69 and 3.21, respectively, so there was significant difference with weeks (P<0.05). Production efficiency factor at 6, 7 and 8 wk old were 256.6, 199.8 and 153.0, respectively, so there was significant difference with weeks (P<0.05). Carcass yield at 8 wk old was higher than that at 6 and 7 wk old as 73.5% (P<0.05). Lightness at 6, 7 and 8 wk were 41.8, 39.0 and 38.1, respectively, and that at 6 wk old was the higher than other weeks (P<0.05). There was no significant difference on redness at 6, 7, and 8 wk old (P>0.05) and yellowness at 8 wk old was higher compared to other weeks (P<0.05). Cooking loss was the highest at 6 wk old as 31.6%, but water holding capacity was the highest at 8 wk old (P<0.05). There was no significant difference on shear force among weeks. pH at 6 wk old was the lower than that of other weeks as 5.84. Moisture content significantly decreased with weeks (P<0.05) and fat content at 8 wk was the highest as 1.88% (P<0.05). Protein content significantly increased with weeks until 20.9% at the age of 8 wk (P<0.05). Ash content at 7 and 8 wk old was the higher than that at 6 wk old (P<0.05). There was no significant difference on juiciness, tenderness, and flavor with weeks. Finally, these results may provide that shipping time at 7 wk old preferred to that at 6 and 7 wk old, but further research was needed because of deficiency of data.

A Study on Maternity Aids Utilization in the Maternal and Child Health and Family Planning (농촌(農村)에 있어서 분만개조요원(分娩介助要員)의 봉사(奉仕)에 의(依)한 모자보건(母子保健)rhk 가족계획(家族計劃)에 관(關) 연구(硏究))

  • Yeh, Min-Hae;Lee, Sung Kwan
    • Journal of Preventive Medicine and Public Health
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    • v.5 no.1
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    • pp.57-95
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    • 1972
  • This study was conducted to assess the effectiveness of service by maternity aids concerning maternal and child health in improving simultaneously infant mortality, contraception and vital registration among expectant mothers in rural Korea, where there is less apportunity for maternal and child health care. It is unrealistic to expect to solve this problem in rural Korea through professional persons considering the situation of medical facilities and the socioeconomic condition of residents. So, we intended to adopt a system of services by maternity aids who were educated formally among indigenous women. After the women were trained in maternal and child health, contraception, and registration for a short period, they were assigned as a maternity aids to each village to help with various activities concerning maternal and child health, for example, registration of pregnant women, home visiting to check for complications, supplying of delivery kits, attendance at delivery, persuasion of contraception, and invitation for registration and so on. Mean-while, four researchers called on the maternity aids to collect materials concerning vital events, maternal child health, contraception and registration, and to give further instruction and supervision as the program proceeded. A. Changes of women's attitude by services of maternity aid. Now, we examined to what extent' such a service system to expectant mothers affected a change in attitude of women residing in the study area as compared to women of the control area. 1) In the birth and death places, there were no changes between last and present infants, in study or control area. 2) In regard to attendants at delivery, there were no changes except for a small percentage of attendance (8%) by maternity aid in study area. But, I expect that more maternity sids could be used as attendants at delivery if they would be trained further and if there was more explanation to the residents about such a service. 3) Considering the rate of utilization of sterilized delivery kit, I am sure that more than 90 percent would be used if the delivery kit were supplied in the proper time. There were significant differences in rates between the study and the control areas. 4) Taking into consideration the utilization rate of the clinic for prenatal care and well baby care, if suck facilities were installed, it would probably be well utilized. 5) In the contraception, the rate of approval was as high as 89 percent in study area as compared to 82 percent in the control area. 6) Considering the rate of pre-and post-partum acceptance on contraception were as much as 70 percent or more, if motivation to use contraception was given to them adequately, the government could reach the goals for family planning as planned. 7) In the vital registration, the rate of birth registration in the study area was some what improved compared to that of the control area, while the rate of death registration was not changed at all. Taking into account the fact that the rate of confirmation of vital events by maternity aids was remarkably high, if the registration system changed to a 'notification' system instead of formal registration ststem, it would be improved significantly compared to present system. B. Effect of the project Thus, with changes in the residents' attitude, was there a reduction in the infant death rate? 1) It is very difficult problem to compare the mortality of infants between last and present infants, because many women don't want to answer accurately about their dead children especially the infants that died within a few days after birth. In this study the data of present death comes from the maternity aides who followed up every pregnancy they had recorded to see what had happened. They seem to have very reliable information on what happened in first few weeks with follow up visitits to check out later changes. From these calculaton, when we compared the rate of infant death between last and present infant, there was remarkable reduction of death rate for present infant compare to that of last children, namely, the former was 30, while the latter 42. The figure is the lowest rate that I have ever heard. As the quality of data we could assess by comparing the causes of death. In the current death rate by communicable disease was much lower compare to the last child especially, tetanus cases and pneumonia. 2) Next, how many respondents used contraception after birth because of frequent contact with the maternity aid. In the registered cases, the respondents showed a tendency to practice contraception at an earlier age and with a small number of children. In a comparison of the rate of contraception between the study and the control area, the rate in the former was significantly higher than that of the latter. What is more, the proportion favoring smaller numbers of children and younger women rose in the study area as compared to the control area. 3) Regarding vital registration, though the rate of registration was gradually improved by efforts of maternity aid, it would be better to change the registration system. 4) In the crude birth rate, the rate in the study area was 22.2 while in the control area was 26.5. Natural increase rate showed 15.4 in the study area, while control area was 19.1. 5) In assessment of the efficiency of the maternity aids judging by the cost-effect viewpoint, the workers in the Medium area seemed to be more efficiency than those of other areas.

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Influence of Hydrothermal Treatment of Wheat Bran on Phytate-P Content and Performance of Broiler Chickens (수침처리가 밀기울의 피틴태 인 함량과 육계의 생산성에 미치는 영향)

  • Kim, B. H.;Paik, I. K.
    • Journal of Animal Science and Technology
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    • v.45 no.2
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    • pp.229-240
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    • 2003
  • An in vitro test and a broiler feeding trial were conducted to test the effect of hydrothermal treatment of wheat bran on phytate-P degradation and it’s feeding effect on performance of broilers. Hydrothermal treatment of wheat bran was carried out at 55$^{\circ}C$ with pH 5.5 buffer solution. Phytate-P content of wheat bran decreased quadrically as the wheat bran: buffer solution ratio increased from 1:0.5 to 1:5. Phytate-P degradation was not significantly affected by incubation times above 10 min., drying temperature (55$^{\circ}C$, 65$^{\circ}C$ and 75$^{\circ}C$) or pH of the buffer solution (5.5 and 7.0). A feeding trial was conducted with 240 sex separated d-old broiler chickens (Ross$^{\circledR}$). Broilers were randomly housed to 24 cages of 10 birds each. Six cages (3 of each sex) were assigned to 4 treatments: Control-normal level of non-phytate-P (NPP); LP-low NPP treatment which had 0.1% lower NPP than Control; LPWB-LP with wheat bran which provided 475 IU of plant phytase per kg diet; LPHWB-LP with hydrothermally treated wheat bran. Results of the feeding trial showed that broilers in the LP treatment gained significantly less than other treatments in starter period (1-21d) but only male broilers for growing LP gained significantly less than Control in the grower (22-35d) and overall period. There were no significant differences in weight gain among the birds of LPWB, LPHWB and Control. Feed intake during the overall period was not significantly different between LPWB and Control but that of LP was lower than LPHWB and that of LPHWB was lower than Control. Feed/gain ratio was significantly lower in LPHWB and LP than in Control and LPWP. Mortality was highest in LPHWB. Availability of crude fat, crude ash and Ca was significantly lower in LP than other treatments. Availability of P and Zn was higher in LPWB and LPHWB than in Control and LP. Availability of P, Mg and Zn was highest in LPHWP treatment. Excretion of P was significantly lower in low NPP treatments than in Control. Serum Ca level was highest whereas serum P level was lowest in LP. Tibial crude ash content was higher in wheat bran treatments, but lower in LP than Control. However, tibial Ca content was higher in Control and LP than wheat bran treatments. Tibial P content of LP and LPWB was lower than Control. However, tibial content of Fe was highest in LP. It was concluded that wheat bran, a source of plant phytase, could be used in low NPP broiler diets to prevent the depression of performance. Reduction of P excretion can be achieved concomitantly. Hydrothermal treatment of wheat bran was effective in improving utilizability of some minerals but was not effective in improving performance of broilers.

A Study on Market Expansion Strategy via Two-Stage Customer Pre-segmentation Based on Customer Innovativeness and Value Orientation (고객혁신성과 가치지향성 기반의 2단계 사전 고객세분화를 통한 시장 확산 전략)

  • Heo, Tae-Young;Yoo, Young-Sang;Kim, Young-Myoung
    • Journal of Korea Technology Innovation Society
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    • v.10 no.1
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    • pp.73-97
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    • 2007
  • R&D into future technologies should be conducted in conjunction with technological innovation strategies that are linked to corporate survival within a framework of information and knowledge-based competitiveness. As such, future technology strategies should be ensured through open R&D organizations. The development of future technologies should not be conducted simply on the basis of future forecasts, but should take into account customer needs in advance and reflect them in the development of the future technologies or services. This research aims to select as segmentation variables the customers' attitude towards accepting future telecommunication technologies and their value orientation in their everyday life, as these factors wilt have the greatest effect on the demand for future telecommunication services and thus segment the future telecom service market. Likewise, such research seeks to segment the market from the stage of technology R&D activities and employ the results to formulate technology development strategies. Based on the customer attitude towards accepting new technologies, two groups were induced, and a hierarchical customer segmentation model was provided to conduct secondary segmentation of the two groups on the basis of their respective customer value orientation. A survey was conducted in June 2006 on 800 consumers aged 15 to 69, residing in Seoul and five other major South Korean cities, through one-on-one interviews. The samples were divided into two sub-groups according to their level of acceptance of new technology; a sub-group demonstrating a high level of technology acceptance (39.4%) and another sub-group with a comparatively lower level of technology acceptance (60.6%). These two sub-groups were further divided each into 5 smaller sub-groups (10 total smaller sub-groups) through two rounds of segmentation. The ten sub-groups were then analyzed in their detailed characteristics, including general demographic characteristics, usage patterns in existing telecom services such as mobile service, broadband internet and wireless internet and the status of ownership of a computing or information device and the desire or intention to purchase one. Through these steps, we were able to statistically prove that each of these 10 sub-groups responded to telecom services as independent markets. We found that each segmented group responds as an independent individual market. Through correspondence analysis, the target segmentation groups were positioned in such a way as to facilitate the entry of future telecommunication services into the market, as well as their diffusion and transferability.

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Herbicidal Phytotoxicity under Adverse Environments and Countermeasures (불량환경하(不良環境下)에서의 제초제(除草劑) 약해(藥害)와 경감기술(輕減技術))

  • Kwon, Y.W.;Hwang, H.S.;Kang, B.H.
    • Korean Journal of Weed Science
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    • v.13 no.4
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    • pp.210-233
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    • 1993
  • The herbicide has become indispensable as much as nitrogen fertilizer in Korean agriculture from 1970 onwards. It is estimated that in 1991 more than 40 herbicides were registered for rice crop and treated to an area 1.41 times the rice acreage ; more than 30 herbicides were registered for field crops and treated to 89% of the crop area ; the treatment acreage of 3 non-selective foliar-applied herbicides reached 2,555 thousand hectares. During the last 25 years herbicides have benefited the Korean farmers substantially in labor, cost and time of farming. Any herbicide which causes crop injury in ordinary uses is not allowed to register in most country. Herbicides, however, can cause crop injury more or less when they are misused, abused or used under adverse environments. The herbicide use more than 100% of crop acreage means an increased probability of which herbicides are used wrong or under adverse situation. This is true as evidenced by that about 25% of farmers have experienced the herbicide caused crop injury more than once during last 10 years on authors' nationwide surveys in 1992 and 1993 ; one-half of the injury incidences were with crop yield loss greater than 10%. Crop injury caused by herbicide had not occurred to a serious extent in the 1960s when the herbicides fewer than 5 were used by farmers to the field less than 12% of total acreage. Farmers ascribed about 53% of the herbicidal injury incidences at their fields to their misuses such as overdose, careless or improper application, off-time application or wrong choice of the herbicide, etc. While 47% of the incidences were mainly due to adverse natural conditions. Such misuses can be reduced to a minimum through enhanced education/extension services for right uses and, although undesirable, increased farmers' experiences of phytotoxicity. The most difficult primary problem arises from lack of countermeasures for farmers to cope with various adverse environmental conditions. At present almost all the herbicides have"Do not use!" instructions on label to avoid crop injury under adverse environments. These "Do not use!" situations Include sandy, highly percolating, or infertile soils, cool water gushing paddy, poorly draining paddy, terraced paddy, too wet or dry soils, days of abnormally cool or high air temperature, etc. Meanwhile, the cultivated lands are under poor conditions : the average organic matter content ranges 2.5 to 2.8% in paddy soil and 2.0 to 2.6% in upland soil ; the canon exchange capacity ranges 8 to 12 m.e. ; approximately 43% of paddy and 56% of upland are of sandy to sandy gravel soil ; only 42% of paddy and 16% of upland fields are on flat land. The present situation would mean that about 40 to 50% of soil applied herbicides are used on the field where the label instructs "Do not use!". Yet no positive effort has been made for 25 years long by government or companies to develop countermeasures. It is a really sophisticated social problem. In the 1960s and 1970s a subside program to incoporate hillside red clayish soil into sandy paddy as well as campaign for increased application of compost to the field had been operating. Yet majority of the sandy soils remains sandy and the program and campaign had been stopped. With regard to this sandy soil problem the authors have developed a method of "split application of a herbicide onto sandy soil field". A model case study has been carried out with success and is introduced with key procedure in this paper. Climate is variable in its nature. Among the climatic components sudden fall or rise in temperature is hardly avoidable for a crop plant. Our spring air temperature fluctuates so much ; for example, the daily mean air temperature of Inchon city varied from 6.31 to $16.81^{\circ}C$ on April 20, early seeding time of crops, within${\times}$2Sd range of 30 year records. Seeding early in season means an increased liability to phytotoxicity, and this will be more evident in direct water-seeding of rice. About 20% of farmers depend on the cold underground-water pumped for rice irrigation. If the well is deep over 70m, the fresh water may be about $10^{\circ}C$ cold. The water should be warmed to about $20^{\circ}C$ before irrigation. This is not so practiced well by farmers. In addition to the forementioned adverse conditions there exist many other aspects to be amended. Among them the worst for liquid spray type herbicides is almost total lacking in proper knowledge of nozzle types and concern with even spray by the administrative, rural extension officers, company and farmers. Even not available in the market are the nozzles and sprayers appropriate for herbicides spray. Most people perceive all the pesticide sprayers same and concern much with the speed and easiness of spray, not with correct spray. There exist many points to be improved to minimize herbicidal phytotoxicity in Korea and many ways to achieve the goal. First of all it is suggested that 1) the present evaluation of a new herbicide at standard and double doses in registration trials is to be an evaluation for standard, double and triple doses to exploit the response slope in making decision for approval and recommendation of different dose for different situation on label, 2) the government is to recognize the facts and nature of the present problem to correct the present misperceptions and to develop an appropriate national program for improvement of soil conditions, spray equipment, extention manpower and services, 3) the researchers are to enhance researches on the countermeasures and 4) the herbicide makers/dealers are to correct their misperceptions and policy for sales, to develop database on the detailed use conditions of consumer one by one and to serve the consumers with direct counsel based on the database.

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