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One-stop Evaluation Protocol of Ischemic Heart Disease: Myocardial Fusion PET Study (허혈성 심장 질환의 One-stop Evaluation Protocol: Myocardial Fusion PET Study)

  • Kim, Kyong-Mok;Lee, Byung-Wook;Lee, Dong-Wook;Kim, Jeong-Su;Jang, Yeong-Do;Bang, Chan-Seok;Baek, Jong-Hun;Lee, In-Su
    • The Korean Journal of Nuclear Medicine Technology
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    • v.14 no.2
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    • pp.33-37
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    • 2010
  • Purpose: In the early stage of using PET/CT, it was used to damper revision but recently shows that CT with MDCT is commonly used and works well for an anatomical diagnosis. This hospital makes the accuracy and convenience more higher in the diagnosis and evaluate of coronary heart disease through concurrently running myocardial perfusion SPECT examination, myocardial PET examination with FDG, and CT coronary artery CT angiography(coronary CTA) used PET/CT with 64-slice. This report shows protocol and image based on results from about 400 coronary heart disease examinations since having 64 channels PET/CT in July 2007. Materials and Methods: An Equipment for this examination is 64-slice CT and Discovery VCT (DVCT) that is consisted of PET with BGO ($Bi_4Ge_3O_{12}$) scintillation crystal by GE health care. First myocardial perfusion SPECT with pharmacologic stress test to reduce waiting time of a patient and get a quick diagnosis and evaluation, and right after it, myocardial FDG PET examination and coronary CTA run without a break. One-stop evaluation protocol of ischemic heart disease is as follows. 1)Myocardial perfusion SPECT with pharmacologic stress: A patient is injected with $^{99m}Tc$-MIBI 10 mCi and does not have any fatty food for myocardial PET examination and drink natural water with ursodeoxcholic acid 100 mg and we get SPECT image in an hour. 2)Myocardial FDG PET: To reduce blood fatty content and to increase uptake of FDG, we used creative oral glucose load using insulin and Acipimox to according to blood acid content. A patient is injected with $^{18}F$-FDG 5 mCi for reduction of his radiation exposure and we get a gated image an hour later and get delay image when we need. 3) Coronary CTA: The most important point is to control heart rate and to get cooperation of patient's breath. In order to reduce a heart rate of him or her below 65 beats, let him or her take beta blocker 50 mg ~ 200 mg after a consultation with a doctor about it and have breath-practices then have the examination. Right before the examination, we spray isosorbide dinitrate 3 to 5 times to lower tension of bessel wall and to extension a blood wall of a patient. It makes to get better the shape of an anatomy. At filming, a patient is injected CT contrast with high pressure and have enough practices before the examination in order to have no problem. For reduction of his radiation exposure, we have to do ECG-triggered X-ray tube modulation exposure. Results: We evaluate coronary artery stenosis through coronary CTA and study correlation (culprit vessel check) of a decline between stenosis and perfusion from the myocardial perfusion SPECT with pharmacologic stress, coronary CTA, and can check viability of infarction or hibernating myocardium by FDG PET. Conclusion: The examination makes us to set up a direction of remedy (drug treatment, PCI, CABG) because we can estimate of effect from remedy, lesion site and severity. In addition, we have an advantage that it takes just 3 hours and one-stop in that all of process of examinations run in succession and at the same time. Therefore it shows that the method is useful in one stop evaluation of ischemic heart disease.

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A Study on the Observation of Soil Moisture Conditions and its Applied Possibility in Agriculture Using Land Surface Temperature and NDVI from Landsat-8 OLI/TIRS Satellite Image (Landsat-8 OLI/TIRS 위성영상의 지표온도와 식생지수를 이용한 토양의 수분 상태 관측 및 농업분야에의 응용 가능성 연구)

  • Chae, Sung-Ho;Park, Sung-Hwan;Lee, Moung-Jin
    • Korean Journal of Remote Sensing
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    • v.33 no.6_1
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    • pp.931-946
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    • 2017
  • The purpose of this study is to observe and analyze soil moisture conditions with high resolution and to evaluate its application feasibility to agriculture. For this purpose, we used three Landsat-8 OLI (Operational Land Imager)/TIRS (Thermal Infrared Sensor) optical and thermal infrared satellite images taken from May to June 2015, 2016, and 2017, including the rural areas of Jeollabuk-do, where 46% of agricultural areas are located. The soil moisture conditions at each date in the study area can be effectively obtained through the SPI (Standardized Precipitation Index)3 drought index, and each image has near normal, moderately wet, and moderately dry soil moisture conditions. The temperature vegetation dryness index (TVDI) was calculated to observe the soil moisture status from the Landsat-8 OLI/TIRS images with different soil moisture conditions and to compare and analyze the soil moisture conditions obtained from the SPI3 drought index. TVDI is estimated from the relationship between LST (Land Surface Temperature) and NDVI (Normalized Difference Vegetation Index) calculated from Landsat-8 OLI/TIRS satellite images. The maximum/minimum values of LST according to NDVI are extracted from the distribution of pixels in the feature space of LST-NDVI, and the Dry/Wet edges of LST according to NDVI can be determined by linear regression analysis. The TVDI value is obtained by calculating the ratio of the LST value between the two edges. We classified the relative soil moisture conditions from the TVDI values into five stages: very wet, wet, normal, dry, and very dry and compared to the soil moisture conditions obtained from SPI3. Due to the rice-planing season from May to June, 62% of the whole images were classified as wet and very wet due to paddy field areas which are the largest proportions in the image. Also, the pixels classified as normal were analyzed because of the influence of the field area in the image. The TVDI classification results for the whole image roughly corresponded to the SPI3 soil moisture condition, but they did not correspond to the subdivision results which are very dry, wet, and very wet. In addition, after extracting and classifying agricultural areas of paddy field and field, the paddy field area did not correspond to the SPI3 drought index in the very dry, normal and very wet classification results, and the field area did not correspond to the SPI3 drought index in the normal classification. This is considered to be a problem in Dry/Wet edge estimation due to outlier such as extremely dry bare soil and very wet paddy field area, water, cloud and mountain topography effects (shadow). However, in the agricultural area, especially the field area, in May to June, it was possible to effectively observe the soil moisture conditions as a subdivision. It is expected that the application of this method will be possible by observing the temporal and spatial changes of the soil moisture status in the agricultural area using the optical satellite with high spatial resolution and forecasting the agricultural production.

Studies on the Virus in Silkworm Bombyx mori L. -Resistance to Virus Disease- (가잠 Virus에 관한 연구 -저항성에 관한 기초조사-)

  • 박광의;강석권
    • Journal of Sericultural and Entomological Science
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    • v.9
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    • pp.67-87
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    • 1969
  • 1. Objectives and Importance. Many silkworms have been damaged by nuclear polyhedrosis virus diseases thoughout the country every year causing a decease in cocoon production by approximately ten per cent per year. The damage caused by the infections virus has occured in spite of complete disinfection. In this respect, it is well known it is impossible, at the present time, to protect the silkworm from these virus infections through chemical and physical control methods. Therefore, this author has attempted to solve this urgent problem from the view point of heredity and breeding, discovering the different resistances and heritabilities among 120 stains collected from throughout the country, and selecting the ones with highest resistance for the basic materials in the silkworm breeding. 2. Results of work 1) The strains with strong resistance to the nuclear polyhedrosis virus diseases are N$_4$, N$\sub$15/, N$\sub$48/, C$\sub$55/ and Em. the log ED$\sub$50/ values of them vary between 0.799 and 1.611. The susceptible strains are N$\sub$20/, C$\sub$62/, N$\sub$76/, N$\sub$79/ and C$\sub$108/, the log ED$\sub$50/ values of them vary between 5.159 and 7.258. (Reference Table 4) The Japanese strain with a log ED$\sub$50/, value of 3.770 is the strongest, followed by the Chinese strain with a log ED$\sub$50/ value of 3.564. The weakest is the European strain with a log ED$\sub$50/ value of 3.3381. The direction coefficient of the regression equation of the susceptibility varies between 0.1 and 0.6, the uniformness of the resistance of the preserved strains of this country is comparatively low. The hereditary henomena of the resistance of each strain and the conerete method of its application for silkworm breeding main the subjects for later studies. 2) The content of water and ash in silkworm has not been correlated with the capability for resistance to the virus diseases(Reference. Table 8). but it is very significantly correlated with mortality rate (in common reaning). In the case of the silkworms which have just completed the fourth moulting the content of water and ash is not related to the mortality rate. In the case of the silkworms which have just completed the third moulting, however, the water( +0.326) and ash (+0.362) registered a high significance. The ash content in the first ($\div$0.520) and second ($\div$0.386) moults is highly significant but water content in both cases is not significant (Reference Table 7). 3) The No. 205 strain proved to be the best in character among the various F$_1$ hybrids. No. 204 was very good in strength but a little lower in cocoon character than the control. No. 212 was a little low in coccon character and mortality was average, but the cocoon harvest was the best among all the varieties offered for (Reference Table 9). 4), In short, the above mentioned strains which are known to have strong resistance to the virus disease are expected to provide basic data for breeding strong varieties. It is proposed that continued research should be conducted on the characteristics of various strains for a satisfactory preservation of various characteristics.research should be conducted on the characteristics of various strains for a satisfactory preservation of various characteristics.

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Studies on the Properties of Populus Grown in Korea (포플러재(材)의 재질(材質)에 관(關)한 시험(試驗))

  • Jo, Jae-Myeong;Kang, Sun-Goo;Lee, Yong-Dae;Jung, Hee-Suk;Ahn, Jung-Mo;Shim, Chong-Supp
    • Journal of the Korean Wood Science and Technology
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    • v.10 no.3
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    • pp.68-87
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    • 1982
  • In Korea, this is the situation at moment that the total demand of timber in 1972 is more than 5 million cubic meters. On the other hand, however, the available domestic supply of timber at the same year is only about, 1 million cubic meters. A great unbalancing between demand and supply of timber has been prevailing. To solve this hard problem, it has been necessitiated to build up the forest stocks as early as possible with fast grown species such as poplar. Under circumstances, poplar plantations which have been carryed on government and private have reached to large area of 116,603 hectors from 1962 up to date. It has now be come a principal timber resources in this country, and required the basic study on various properties of wood for it's proper utilization, since it has not been made of any systematic study on the properties of Populus grown in Korea. In order to investigate the properties such as anatomical, physical and mechanical properties of nine different species (P. euramericana Guiner I-214. P. euramericana Guiner I-476, P. deltoides Marsh, P. nigra var. italica (Muchk) Koeme, P. alba L.,P. alba $\times$ glandulosa P. maximowiczii Henry, P. koreana Rehder, P. davidiana Dode) of poplar for their proper use and development of new ways of grading processing and quality improving, this study has been made by the Forest Research Institute.

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The Study about Application of LEAP Collimator at Brain Diamox Perfusion Tomography Applied Flash 3D Reconstruction: One Day Subtraction Method (Flash 3D 재구성을 적용한 뇌 혈류 부하 단층 촬영 시 LEAP 검출기의 적용에 관한 연구: One Day Subtraction Method)

  • Choi, Jong-Sook;Jung, Woo-Young;Ryu, Jae-Kwang
    • The Korean Journal of Nuclear Medicine Technology
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    • v.13 no.3
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    • pp.102-109
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    • 2009
  • Purpose: Flash 3D (pixon(R) method; 3D OSEM) was developed as a software program to shorten exam time and improve image quality through reconstruction, it is an image processing method that usefully be applied to nuclear medicine tomography. If perfoming brain diamox perfusion scan by reconstructing subtracted images by Flash 3D with shortened image acquisition time, there was a problem that SNR of subtracted image is lower than basal image. To increase SNR of subtracted image, we use LEAP collimators, and we emphasized on sensitivity of vessel dilatation than resolution of brain vessel. In this study, our purpose is to confirm possibility of application of LEAP collimators at brain diamox perfusion tomography, identify proper reconstruction factors by using Flash 3D. Materials and methods: (1) The evaluation of phantom: We used Hoffman 3D Brain Phantom with $^{99m}Tc$. We obtained images by LEAP and LEHR collimators (diamox image) and after 6 hours (the half life of $^{99m}Tc$: 6 hours), we use obtained second image (basal image) by same method. Also, we acquired SNR and ratio of white matters/gray matters of each basal image and subtracted image. (2) The evaluation of patient's image: We quantitatively analyzed patients who were examined by LEAP collimators then was classified as a normal group and who were examined by LEHR collimators then was classified as a normal group from 2008. 05 to 2009. 01. We evaluate the results from phantom by substituting factors. We used one-day protocol and injected $^{99m}Tc$-ECD 925 MBq at both basal image acquisition and diamox image acquisition. Results: (1) The evaluation of phantom: After measuring counts from each detector, at basal image 41~46 kcount, stress image 79~90 kcount, subtraction image 40~47 kcount were detected. LEAP was about 102~113 kcount at basal image, 188~210 kcount at stress image and 94~103 at subtraction image kcount were detected. The SNR of LEHR subtraction image was decreased than LEHR basal image about 37%, the SNR of LEAP subtraction image was decreased than LEAP basal image about 17%. The ratio of gray matter versus white matter is 2.2:1 at LEHR basal image and 1.9:1 at subtraction, and at LEAP basal image was 2.4:1 and subtraction image was 2:1. (2) The evaluation of patient's image: the counts acquired by LEHR collimators are about 40~60 kcounts at basal image, and 80~100 kcount at stress image. It was proper to set FWHM as 7 mm at basal and stress image and 11mm at subtraction image. LEAP was about 80~100 kcount at basal image and 180~200 kcount at stress image. LEAP images could reduce blurring by setting FWHM as 5 mm at basal and stress images and 7 mm at subtraction image. At basal and stress image, LEHR image was superior than LEAP image. But in case of subtraction image like a phantom experiment, it showed rough image because SNR of LEHR image was decreased. On the other hand, in case of subtraction LEAP image was better than LEHR image in SNR and sensitivity. In all LEHR and LEAP collimator images, proper subset and iteration frequency was 8 times. Conclusions: We could archive more clear and high SNR subtraction image by using proper filter with LEAP collimator. In case of applying one day protocol and reconstructing by Flash 3D, we could consider application of LEAP collimator to acquire better subtraction image.

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A Study of Educational System for Medical Technologists in Korea (한국(韓國)의 의료기사(醫療技士) 교육제도(敎育制度)에 관(關)한 조사(調査) 연구(硏究))

  • Song, Jae-Kwan;Lee, Gun-Sub;Kim, Byong-Lak;Kim, Chung-Rak;Cho, Jun-Suk;Huh, Joon;Lee, Joon-Il
    • Journal of radiological science and technology
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    • v.6 no.1
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    • pp.131-181
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    • 1983
  • After the investigation on, and the analysis of, the educational system for medical technicians and the present educational situation for medical technologies in this country, the following conclusions were drawn. 1. As of March 1983 the current academic system for education in medical technologies included the regular 4-year college courses and those of the 2-year professional junior college courses. But except in the cases on clinical pathology and physical therapy, there were no college-level departments. Particularly, no educational institutions, at whatever level, had a department for working therapies. 2. The total number of credits needed for graduation from a department of medical technologies was 150 points at a regular 4-year college and 85 to 96 points at a 2-year professional college. The obligatory minimum number of credits for a student at a professional college was set at 80 points and above. 3. As for the number of the educational institutions for medical technologies in this country, there were one regular college and 14 professional colleges, a total of 15 institutions. As many as 14 colleges had departments of clinical pathology, 12 had departments of Radiotechnology, 11 had departments of physical therapy, 12 had departments of dental technology, and eight had departments of dental hygiene. 4. The total capacity of the professional colleges in admitting new enrollment each year were 1,920 for clinical pathology, 1,552 for radiology, 1,012 for physical therapy, 1,334 for dental technologies, 828 for dental hygiene, an aggregate of 6,646 for all of the professional college departments. 5. The total number of graduates from the 12 professional colleges by department during the period of 1965-83 were 7,595 for clindical pathology, 4,768 for radiology, 2,821 for physical therapy, 3,000 for dental technologies, and 1,787 for dental hygiene, totalling 19,971 for all departments in the professional colleges. 6. In the state examination for licensed medical technicians, 12,446 have passed from among the total of 26,609 participants, representing a 45% passing ratio. By departments the ratios showed 44% for clinical pathology, 39.7% for radiology, 51.2% for physical therapy, 42.5% for dental technology, 72.5% for dental hygiene and 73.1% for working therapy. 7. As for the degree of satisfaction shown by the people in this field, 52.2 percent of the teaching staffs who responed to the questionaires said they were satisfied with their present profession, while the great majority of medical technicians(66%) replied that they were indifferent to the problem. 8. The degree of satisfaction shown by the students on their enrollment in this particular academic field was generally in the framework of indifference(43.7%), but mere students(36.5%) were satisfied with their choice than those were not satisfied(14.4%) 9. As for the student's opinions on the lectures and practicing hours, a good many students replied that, among such courses as general science and humanities courses the basic medical course, the major course and practicing hours, the hours provided for the general courses(47.1%) and practicing(47.6%) were insufficient. 10. When asked about the contents of their major courses, comparatively few students (23.6%) replied that the courses were too difficult, while a convincing majority(58.5%) said they were neither difficult nor easy. As for the appropriateness of the number of the present teaching staffs, a great majority(71.0%) of the students replied that the level of the teaching personnel in each particular field was insufficient. 11. Among the students who responded to the poll, good part of them(49.5%) wanted mandatory clinical practicing hours, and the the majority of them(64.6%) held the view that the experimental and practicing facilities of their schools were insufficient. 12. On the necessity of the attached hospitals, 71.1% of the teaching staffs and 58.0% of the medical technicians had the opinion that this kind of facility was indispensable. 13. As for the qualifications for applicants to the state examination in the licensing system for medical technicians, 52.2% of the teacher's and 36% of the medical technicians replied that the present system granting the qualifications according to the apprenticeship period should be abolished. 14. On the necessity of improving the present system for education in medical technologies, an overwhelming majority(94.4% of the :caching staffs, 92.0% of the medical technicians and 91.9% of students) of these polled replied that the present system should be changed for the better. 15. On the method of changes for the present educational system, a great majority(89.4% of the teaching staffs, 80.4% of the medical technicians and 90.1% of the students) said that the system must be changed so that it fits into the reality of the present day. 16. As for the present 2-year program for the professional colleges, 61.6% of the teachers, 72.0% of the medical technicians and 38.8% of the students expressed the hope that the academic period would be extended to four regular years, hemming a full-fledged collegelevels program. 17. On the life-long eductional system for medical technicians, there was a considerable number of people who expressed the hope that an open university system(38.9% of the teaching staffs, 36.0% of the medical technicians) and a graduate school system would be set up. 18. As for the future prospects for medical technicians as professionals, the optimists ana pessimists were almost equally divided, and 41.1% of the teaching staffs 36.0% of. the technicians and 50.5% of the students expressed an intermediate position on this issue.

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Diving patterns and diving related disease of diving fishermen in Korea (수산물채취 잠수부의 작업특성과 잠수관련질환의 양상)

  • SaKong, Joon
    • Journal of Preventive Medicine and Public Health
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    • v.31 no.1 s.60
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    • pp.139-156
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    • 1998
  • Diving related disease including decompression sickness is an important occupational health problem and diving fishermen remain a fairly hazardous occupation in Korea. To prevent diving related disease, we investigate diving patterns, incidence of diving related diseases, and contributing factors of 433 diving fishermen of three coast interviewing and mailing questionnaire in 1996. Mean age of divers was 39.7 years, ranged from 24 to 58 years, 92.8% of these were male, and 58.4% of divers were high school graduates. Mean duration of work as a diver was 12.9 years, ranged from 2 to 40 years. It was found that 70.4% of divers were using hookah system, 22.2% of helmet, and only 2.5% SCUBA. About half of them have learned diving skills from other divers. The peak season of diving was from April to June and mean working days were 20.3 days per month during the peak season. On the average, the divers dived 5-6 times, ranged from 1 to 10 times a day with 51.1 minutes of diving time, ranged from 20 to 120 minutes, at 30 m or 40 m in depth, and 35.5 minute of interval on surface. Most divers ascended slowly making decompression stop, yet the decompression profile used was not based on any scientific knowledge except for their own experiences. It appeared that each diving system had slightly different diving patterns. There were 282(65.0%) divers that suffered from DCS in 1995 and 31.2% of divers were given recompression therapy at a medical facility since they worked as diving fishermen. Skin and musculoskeletal complaints were common symptoms of DCS and 39% of divers experienced a voiding difficulty. In univariate analysis, females have an increased frequency of DCS(93% vs 66% for males). Old age, long duration of work, helmet diving, diving time, diving depth, repetitive diving, and blow up were all contributing factors to DCS. It was found that most diving patterns exceed no decompression limit and did not use the standard decompression table. This suggests that most of divers are at high risk of developing diving related disease with prolonged dives and lengthy repetitive diving in deep depth. Considering the diving patterns and economic aspect of professional diving, the incidence of DCS among diving fishermen in Korea will not decrease in the near future. These findings suggest that periodical health surveillance for divers, and education of health and safety are important for reducing the risk of diving related disease in the population of diving fishermen.

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Ideal Right Ventricular Outflow Tract Size in Tetralogy of Fallot Total Correction (팔로네징후 완전교정술 시 이상적인 우심실 유출로 크기에 관한 분석)

  • Kim Jin-Sun;Choi Jin-Ho;Yang Ji-Hyuk;Park Pyo-Won;Youm Wook;Jun Tae-Gook
    • Journal of Chest Surgery
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    • v.39 no.8 s.265
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    • pp.588-597
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    • 2006
  • Background: The surgical repair of a tetralogy of Fallot (TOF) has been performed successfully with a favorable early and late outcome. However, the later development of pulmonary regurgitation and stenosis remains a problem. The development of pulmonary regurgitation and stenosis may be changed by the size of right ventricular outflow tract (RVOT) reconstruction at the initial total correction. Hence, it is necessary to investigate the ideal size of RVOT reconstruction. Material and Method: This prospective study was carried out to determine how a surgical strategy and the RVOT size affect the occurrence of pulmonary regurgitation and stenosis. From January 2002 to December 2004, 62 patients underwent the TOF total correction. The RVOT size (diameter of pulmonary valve annulus) of each case was measured after the RVOT reconstruction and converted to a Z value. A pre-scheduled follow up (at discharge, 6 months, 1 year, 2 years and 3 years) was carried out by echocardiography to evaluate the level of pulmonary regurgitation and stenosis. Result: The patients were divided to two groups (transannular group n=12, nontransannular group n=50) according to the method of a RVOT reconstruction. The Z value of RVOT=iameter of pulmonary valve annulus) (transannular group -1, $range\;-3.6{\sim}-0.8;$ nontransannular group -2.1, $range\;-5.2{\sim}-1.5)$ and the average pRV/LV after surgery ${(transannular group 0.44{\pm}0.09,\;nontransannular group\;0.42{\pm}0.09)}$ did not show any significant difference between two groups. The occurrence of pulmonary regurgitation above a moderate degree was more frequent in the transannular group (p<0.01). In nontransannular group, the development of pulmonary regurgitation more than moderate degree occurred to the patients with larger RVOT size (Z value>0, p<0.02) and the progressing pulmonary stenosis more than mild to moderate degree developed in the patients with smaller RVOT size (Z value<-1.5, p<0.05). A moderate degree of pulmonary stenosis developed for 4 nontransannular patients. Three underwent additional surgery and one underwent a balloon valvuloplasty. Their Z value of RVOT were -3.8, -3.8 -2.9, -1.8, respectively. Conclusion: When carring out a TOF total correction, transannular RVOT reconstruction group has significantly more pulmonary regurgitation. In the nontransannular RVOT reconstruction. the size of the RVOT should be maintained from Z value -1.5 to 0. If the Z value is less than -1.5, we should follow up carefully for the possibility of pulmonary stenosis.

Mature Market Sub-segmentation and Its Evaluation by the Degree of Homogeneity (동질도 평가를 통한 실버세대 세분군 분류 및 평가)

  • Bae, Jae-ho
    • Journal of Distribution Science
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    • v.8 no.3
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    • pp.27-35
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    • 2010
  • As the population, buying power, and intensity of self-expression of the elderly generation increase, its importance as a market segment is also growing. Therefore, the mass marketing strategy for the elderly generation must be changed to a micro-marketing strategy based on the results of sub-segmentation that suitably captures the characteristics of this generation. Furthermore, as a customer access strategy is decided by sub-segmentation, proper segmentation is one of the key success factors for micro-marketing. Segments or sub-segments are different from sectors, because segmentation or sub-segmentation for micro-marketing is based on the homogeneity of customer needs. Theoretically, complete segmentation would reveal a single voice. However, it is impossible to achieve complete segmentation because of economic factors, factors that affect effectiveness, etc. To obtain a single voice from a segment, we sometimes need to divide it into many individual cases. In such a case, there would be a many segments to deal with. On the other hand, to maximize market access performance, fewer segments are preferred. In this paper, we use the term "sub-segmentation" instead of "segmentation," because we divide a specific segment into more detailed segments. To sub-segment the elderly generation, this paper takes their lifestyles and life stages into consideration. In order to reflect these aspects, various surveys and several rounds of expert interviews and focused group interviews (FGIs) were performed. Using the results of these qualitative surveys, we can define six sub-segments of the elderly generation. This paper uses five rules to divide the elderly generation. The five rules are (1) mutually exclusive and collectively exhaustive (MECE) sub-segmentation, (2) important life stages, (3) notable lifestyles, (4) minimum number of and easy classifiable sub-segments, and (5) significant difference in voices among the sub-segments. The most critical point for dividing the elderly market is whether children are married. The other points are source of income, gender, and occupation. In this paper, the elderly market is divided into six sub-segments. As mentioned, the number of sub-segments is a very key point for a successful marketing approach. Too many sub-segments would lead to narrow substantiality or lack of actionability. On the other hand, too few sub-segments would have no effects. Therefore, the creation of the optimum number of sub-segments is a critical problem faced by marketers. This paper presents a method of evaluating the fitness of sub-segments that was deduced from the preceding surveys. The presented method uses the degree of homogeneity (DoH) to measure the adequacy of sub-segments. This measure uses quantitative survey questions to calculate adequacy. The ratio of significantly homogeneous questions to the total numbers of survey questions indicates the DoH. A significantly homogeneous question is defined as a question in which one case is selected significantly more often than others. To show whether a case is selected significantly more often than others, we use a hypothesis test. In this case, the null hypothesis (H0) would be that there is no significant difference between the selection of one case and that of the others. Thus, the total number of significantly homogeneous questions is the total number of cases in which the null hypothesis is rejected. To calculate the DoH, we conducted a quantitative survey (total sample size was 400, 60 questions, 4~5 cases for each question). The sample size of the first sub-segment-has no unmarried offspring and earns a living independently-is 113. The sample size of the second sub-segment-has no unmarried offspring and is economically supported by its offspring-is 57. The sample size of the third sub-segment-has unmarried offspring and is employed and male-is 70. The sample size of the fourth sub-segment-has unmarried offspring and is not employed and male-is 45. The sample size of the fifth sub-segment-has unmarried offspring and is female and employed (either the female herself or her husband)-is 63. The sample size of the last sub-segment-has unmarried offspring and is female and not employed (not even the husband)-is 52. Statistically, the sample size of each sub-segment is sufficiently large. Therefore, we use the z-test for testing hypotheses. When the significance level is 0.05, the DoHs of the six sub-segments are 1.00, 0.95, 0.95, 0.87, 0.93, and 1.00, respectively. When the significance level is 0.01, the DoHs of the six sub-segments are 0.95, 0.87, 0.85, 0.80, 0.88, and 0.87, respectively. These results show that the first sub-segment is the most homogeneous category, while the fourth has more variety in terms of its needs. If the sample size is sufficiently large, more segmentation would be better in a given sub-segment. However, as the fourth sub-segment is smaller than the others, more detailed segmentation is not proceeded. A very critical point for a successful micro-marketing strategy is measuring the fit of a sub-segment. However, until now, there have been no robust rules for measuring fit. This paper presents a method of evaluating the fit of sub-segments. This method will be very helpful for deciding the adequacy of sub-segmentation. However, it has some limitations that prevent it from being robust. These limitations include the following: (1) the method is restricted to only quantitative questions; (2) the type of questions that must be involved in calculation pose difficulties; (3) DoH values depend on content formation. Despite these limitations, this paper has presented a useful method for conducting adequate sub-segmentation. We believe that the present method can be applied widely in many areas. Furthermore, the results of the sub-segmentation of the elderly generation can serve as a reference for mature marketing.

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A Model for Health Promoting Behaviors in Late-middle Aged Woman (중년후기 여성의 건강증진행위 모형구축)

  • Park, Chai-Soon
    • Women's Health Nursing
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    • v.2 no.2
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    • pp.298-331
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    • 1996
  • Recent improvements in living standard and development in medical care led to an increased interest in life expectancy and personal health, and also led to a more demand for higher quality of life. Thus, the problem of women's health draw a fresh interest nowadays. Since late-middle aged women experience various physical and socio-psychological changes and tend to have chronic illnesses, these women have to take initiatives for their health control by realizing their own responsibility. The basic elements for a healthy life of these women are understanding of their physical and psychological changes and acceptance of these changes. Health promoting behaviors of an individual or a group are actions toward increasing the level of well-being and self-actualization, and are affected by various variables. In Pender's health promoting model, variables are categorized into cognitive factors(individual perceptions), modifying factors, and variables affecting the likelihood for actions, and the model assumes the health promoting behaviors are affected by cognitive factors which are again affected by demographic factors. Since Pender's model was proposed based on a tool broad conceptual frame, many studies done afterwards have included only a limited number of variables of Pender's model. Furthermore, Pender's model did not precisely explain the possibilities of direct and indirect paths effects. The objectives of this study are to evaluate Pender's model and thus propose a model that explains health promoting behaviors among late-middle aged women in order to facilitate nursing intervention for this group of population. The hypothetical model was developed based on the Pender's health promoting model and the findings from past studies on women's health. Data were collected by self-reported questionnaires from 417 women living in Seoul, between July and November 1994. Questionnaires were developed based on instruments of Walker and others' health promotion lifestyle profile, Wallston and others' multidimensional health locus of control, Maoz's menopausal symptom check list and Speake and others' health self-rating scale. IN addition, items measuring self-efficacy were made by the present author based on past studies. In a pretest, the questionnaire items were reliable with Cronbach's alpha ranging from .786 to .934. The models for health promoting behaviors were tested by using structural equation modelling technique with LISREL 7.20. The results were summarized as follows : 1. The overall fit of the hypothetical model to the data was good (chi-square=4.42, df=5, p=.490, GFI=.995, AGFI=.962, RMSR=.024). 2. Paths of the model were modified by considering both its theoretical implication and statistical significance of the parameter estimates. Compared to the hypothetical model, the revised model has become parsimonious and had a better fit to the data (chi-square =4.55, df=6, p=.602, GFI=.995, AGFI=.967, RMSR=.024). 3. The results of statistical testing were as follows : 1) Family function internal health locus of control, self-efficacy, and education level exerted significant effects on health promoting behaviors(${\gamma}_{43}$=.272, T=3.714; ${\beta}_[41}$=.211, T=2.797; ${\beta}_{42}$=.199, T=2.717; ${\gamma}_{41}$=.136, T=1.986). The effect of economic status, physical menopausal symptoms, and perceived health status on health promoting behavior were insignificant(${\gamma}_{42}$=.095, T=1.456; ${\gamma}_{44}$=.101, T=1.143; ${\gamma}_{43}$=.082, T=.967). 2) Family function had a significance direct effect on internal health locus of control (${\gamma}_{13}$=.307, T=3.784). The direct effect of education level on internal health locus of control was insignificant(${\gamma}_{11}$=-.006, T=-.081). 3) The directs effects of family functions & internal health locus of control on self-efficacy were significant(${\gamma}_{23}$=.208, T=2.607; ${\beta}_{21}$=.191, T=2.2693). But education level and economic status did not exert a significant effect on self-efficacy(${\gamma}_{21}$=.137, T=1.814; ${\beta}_{22}$=.137, T=1.814; ${\gamma}_{22}$=.112, T=1.499). 4) Education level had a direct and positive effect on perceived health status, but physical menopausal symptoms had a negative effect on perceived health status and these effects were all significant(${\gamma}_{31}$=.171, T=2.496; ${\gamma}_{34}$=.524, T=-7.120). Internal health locus and self-efficacy had an insignificant direct effect on perceived health status(${\beta}_{31}$=.028, T=.363; ${\beta}_{32}$=.041, T=.557). 5) All predictive variables of health promoting behaviors explained 51.8% of the total variance in the model. The above findings show that health promoting behaviors are explained by personal, environmental and perceptual factors : family function, internal health locus of control, self-efficacy, and education level had stronger effects on health promoting behaviors than predictors in the model. A significant effect of family function on health promoting behaviors reflects an important role of the Korean late-middle aged women in family relationships. Therefore, health professionals first need to have a proper evaluation of family function in order to reflect the family function style into nursing interventions and development of strategies. These interventions and strategies will enhance internal health locus of control and self-efficacy for promoting health behaviors. Possible strategies include management of health promoting programs, use of a health information booklets, and individual health counseling, which will enhance internal health locus of control and self-efficacy of the late-middle aged women by making them aware of health responsibilities and value for oneself. In this study, an insignificant effect of physical menopausal symptoms and perceived health status on health promoting behaviors implies that they are not motive factors for health promoting behaviors. Further analytic researches are required to clarify the influence of physical menopausal symptoms and perceived health status on health promoting behaviors with-middle aged women.

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