• Title/Summary/Keyword: Indirect Method

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Evaluate Utility of Thyroid Incidentaloma Discrimination by $^{18}F$-FDG PET/CT Delay Scan Images ($^{18}F$-FDG PET/CT검사에서 지연영상을 이용한 갑상선 우연종 감별의 유용성 평가)

  • Lee, Hyun-Kuk;Yang, Seoung-Oh;Song, Gi-Deok;Song, Chi-Ock;Lee, Gi-Heun
    • The Korean Journal of Nuclear Medicine Technology
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    • v.12 no.3
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    • pp.184-191
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    • 2008
  • Purpose: To evaluate the degree of malignancy of incident thyroid lesion found in $^{18}F$-FDG PET/CT findings and the usefulness of the method suggested in this study, we applicate the Delay Scan Method that differentiate a false positive benign tumor, inflammation and malignancy, as well as make the criteria of SUV. Materials and Methods: A retrograde study was conducted of 800 patients who were admitted in E hospital to receive $^{18}F$-FDG PET/CT examination. One patient who was diagnosed as primary thyroid cancer and received $^{18}F$-FDG PET/CT examination was excluded. The number of final patients of this study was 799, the reasons of $^{18}F$-FDG PET/CT examination of these patients were follow-up of old cancer or suspicious tumorous lesion in 696 and disease screening in 103. $^{18}F$-FDG PET/CT image photographing was taken in Biograph-Duo made by SIEMENS, after taking normal $^{18}F$-FDG PET/CT image (1 hr) and then 1 hr later we took the thyroid 1 bed-delayed image for the patients who showed abnormal thyroid $^{18}F$-FDG uptake and above 2.0 SUV for 2 minutes every 1 bed. For the patients who showed abnormal thyroid uptake and above 2.0 SUV, 1 hr later, we took a 1 bed-delayed image and then made a comparative study between measured $SUV_{max}$ of 1 hr-abnormal uptake image and that of 2 hr-delayed image. Results and Conclusion: In this $^{18}F$-FDG PET/CT study among the patients who showed incidental $^{18}F$-FDG thyroidal uptake the number of thyroid incidentaloma was 5 (0.63%), all of then showed benign findings. And in the case of incidental $^{18}F$-FDG uptake in thyroid, $SUV_{max}$ variance obtained from 2 hr delayed image can be a indirect criteria in differentiating benign tumor from malignancy and decrease finding error. In the cases found thyroid incidentaloma when 1) $SUV_{max}$ of focal thyroid lesion is above 5.0 and 2) $SUV_{max}$ variance between normal $^{18}F$-FDG PET/CT exam and 2 hr delayed is $1.0{\pm}0.5$, they are suspected as malignancy and confirming biopsy is to be followed. Otherwise, I also think that distinct follow-up PET or CT image study is a reasonable diagnostic method.

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The development of conductive 10B thin film for neutron monitoring (중성자 모니터링을 위한 전도성 10B 박막 개발)

  • Lim, Chang Hwy;Kim, Jongyul;Lee, Suhyun;Jung, Yongju;Choi, Young-Hyun;Baek, Cheol-Ha;Moon, Myung-Kook
    • Journal of Radiation Protection and Research
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    • v.39 no.4
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    • pp.199-205
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    • 2014
  • In the field of neutron detections, $^3He$ gas, the so-called "the gold standard," is the most widely used material for neutron detections because of its high efficiency in neutron capturing. However, from variable causes since early 2009, $^3He$ is being depleted, which has maintained an upward pressure on its cost. For this reason, the demands for $^3He$ replacements are rising sharply. Research into neutron converting materials, which has not been used well due to a neutron detection efficiency lower than the efficiency of $^3He$, although it can be chosen for use in a neutron detector, has been highlighted again. $^{10}B$, which is one of the $^3He$ replacements, such as $BF_3$, $^6Li$, $^{10}B$, $Gd_2O_2S$, is being researched by various detector development groups owing to a number of advantages such as easy gamma-ray discrimination, non-toxicity, low cost, etc. One of the possible techniques for the detection is an indirect neutron detection method measuring secondary radiation generated by interactions between neutrons and $^{10}B$. Because of the mean free path of alpha particle from interactions that are very short in a solid material, the thickness of $^{10}B$ should be thin. Therefore, to increase the neutron detection efficiency, it is important to make a $^{10}B$ thin film. In this study, we fabricated a $^{10}B$ thin film that is about 60 um in thickness for neutron detection using well-known technology for the manufacturing of a thin electrode for use in lithium ion batteries. In addition, by performing simple physical tests on the conductivity, dispersion, adhesion, and flexibility, we confirmed that the physical characteristics of the fabricated $^{10}B$ thin film are good. Using the fabricated $^{10}B$ thin film, we made a proportional counter for neutron monitoring and measured the neutron pulse height spectrum at a neutron facility at KAERI. Furthermore, we calculated using the Monte Carlo simulation the change of neutron detection efficiency according to the number of thin film layers. In conclusion, we suggest a fabrication method of a $^{10}B$ thin film using the technology used in making a thin electrode of lithium ion batteries and made the $^{10}B$ thin film for neutron detection using suggested method.

Statistical Evaluation of Moisture Resistance by Mixing Method of Recycled Asphalt Mixtures (혼합방법에 따른 순환아스팔트 혼합물의 수분저항성 통계검정 평가)

  • Kim, Sungun;Kim, Yeongsam;Jo, Youngjin;Kim, Kwangwoo
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.9 no.2
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    • pp.167-176
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    • 2021
  • When producing recycled asphalt mix, it is important that the old binder of reclaimed asphalt pavement(RAP) should be well melted during blending in the mixer. The recycled asphalt mix is produced by instant mixing(IM) of all materials(RAP, virgin asphalt and new aggregates) all together in the mixer. However, in the same recycled mix, the binder around RAP aggregate was found to show higher oxidation level than the binder coated around the virgin aggregate because the old binder of RAP was not rejuvenated properly while instant mixing. The partially-rejuvenated RAP binder is assumed to be a high stiffness point in IM recycled mix. In this study, the stage mixing(SM) method was introduced; blending RAP and virgin asphalt for the first stage, and then mixing all together with hot new aggregates for the second stage. To compare the effect of the two mixing methods on moisture resistance of recycled mixes, a statistical t-test was performed between SM and IM using indirect tensile strength(ITS) and tensile strength ratio(TSR). Three conditioning methods were used; a 16-h freezing and then 24-h submerging, 48-h submerging, and 72-h submerging in 60℃ water. It was found that the TSR(=ITSwet/ITSdry) values of the mixes prepared by SM was clearly higher than the IM mixes, and coefficients of variation of SM mixes were lower than the IM mixes. It was also observed that the ITSWET of SM was significantly different from the IM at α=0.05 level by statistical t-test. The ITSWET of SM mix was reduced less than the IM mix in severer conditioned mixes. Therefore, it was concluded that the stage mixing method was an important blending technique for producing better-quality of recycled asphalt mixes, which would show higher moisture resistance than the recycled mixes produced by conventional instant mixing.

A Study on Accounting for Nursing Cost by Korean Diagnosis Related Groups (K - DRGs) (종합병원(綜合病院)의 간호행위양상(看護行爲樣相)에 따른 간호원가(看護原價) 산정(算定)에 관(關)한 연구(硏究))

  • Oh, Hyo-Sook
    • Journal of Korean Public Health Nursing
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    • v.3 no.2
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    • pp.5-46
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    • 1989
  • The current medical payment Insurance Rates in Korea stipulate charges for medical treatment by the doctor, pharmaceutist, medical technician and maternity nurse. But unfortunately didn't specify those charges for nursing done by the professional nurse. Only basic nursing fee is accounted insufficiently in current medical insurance fee schedule. therefore, Being face with covering entire people by medical insurance by 1991, It seems that the problems pertaining to operating the hospital and medical insurance system would be incessantly expanded in that no mention is made of medical charges rendered by major medical producer service in the current system, For that reason, this study made an attempt to clarify the importance the professional nursing puts of the current medical payment. The purpose of this study was to accounting nursing fee which diveded into the current medical fee schedule. (Method) 1. Data collection; Importance and difficulties in nursing activities was conducted in 'S' National University Hospital. Total nursing activities were selected 72 items which included direct care and indirect care. This study was conducted to evaluating the degree of importance and difficulties according to nursing activities through questionnaire to 204 RN. and so relative difficulties (acuity) were computered because the nursing cost level of each nursing service was differently established by the equivalent coefficient according to degree of relative difficulty and time required. 2. Calculation of cost according to nursing activities; After 47 nursing activities were selected in General surgery nursing units, calculation of nursing cost was as follows Cost of Nursing activity = (relative difficulty X Average hourly wage and benefits of nurse) + material cost of nursing -t- Average nursing administration cost So, Calculated cost by nursing activities was compared to current non-insured and insurance rate. 3. Calculation of nursing cost by K - DRG ; Total of 578 patients who were hospitalized in General Surgery units from January to March 1988 ware classified by K - DRG After estimation of total nursing cost based on the K-DRG, verified the appropriateness of basic nursing fee in medical insurance rate (Results) 1. Analysis of degree of importance and difficulties were 4.16 and 3.67 based on 5 point scale. This score were judged that it is worthy specifying the nursing fee 2. The nursing cost of 47 nursing service items in general surgery patients showed that the average cost of nursing activity was \1374.5 and The lowest cost was \217 of 'oral administration nursing' item, The highest cost was \11,025 of 'saline enematill clear' item 3. The result of comparison between the calculated cost by nursing activities against the current non-insured and insurance rate showed that 13 items(27.7%) involved to payment of insurance rate, 9 items(19.1%) involved to non-insured rate, remainder 25 items (53.2%) were not charged anywhere of total 47 nursing activities 4. When calculated cost by nursing activities was 100. current insurance rate was 62.3, non-insured rate was 176.6. Therefore this showed that most of non-insured rate were higher than calculated nursing cost. The insurance rate, however, were lower than it. Reim-bursement was imputed to non-insured patients. So the current rate system became estrainged from cost system. When Remainder 25 items of nursing activities compared' to \1390 of daily basic nursing fee per patient belonged to payment as a insurance fee schedule, basic nursing fee schedule was 1-2% of calculated cost of nursing activities. Therefore it showed that nursing fee was not counted adequately in it. 5. Nursing cost by K-DRG estimated in chart review based on counting number of nursing activities and length of stay The result showed that average amount of total nursing cost was \183828.1 Comparison of nursing cost calculated by K- DRG and basic nursing fee schedule showed that only 12.3% of nursing cost was charged (Conclusion) From the above research result, It is fact that nursing prime cost should be estimated more accurately and included adequately in current medical payment system. The payment system of nursing activities should be introduced not only nursing activities of drug administration and injection fee belonged to insurance fee schedule but also most nursing activities belonged not to mekical fee schedule. Even if introducing payment system of nursing activities, It should be estimated scientific method of Accounting nursing cost So nurses could offer nursing care of good quality, thereby they could make a great contribution not merely to the convalescence of the patient but to the promotion of the people's health.

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Surface Marker Analysis in Acute Leukemias (백혈병의 면역학적 표지자검사의 결과분석)

  • Moon, Jin-Young;Lee, Chae-Hoon;Kim, Kyung-Dong;Kim, Chung-Sook
    • Journal of Yeungnam Medical Science
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    • v.14 no.2
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    • pp.359-369
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    • 1997
  • We studied the expression of the cell surface antigen associated with myeloid and lymphoid leukemias on bone marrow or peripheral blood blast cells from 153 leukemic patients including 61 cases of acute myelogenous leukemias(AML), 46 of acute lymphocytic leukemias(ALL) and 12 of acute leukemias. They were analyzed by direct or indirect immunofluorescence method for reactivity with the monoclonal antibodies to B cells(CD10, CD19, SmIg), T cells(CD2, CD5, CD7, CD3, CD4, CD8), myeloid antigen(CD13, CD14, CD33, CD61) and a nonspecific antigen, HLA-DR. Lymphoid associated markers detected on AML is CD7 32.8%, CD10 14.8%, CD5 13.1%, CD2 6.6% and CD19 1.6%. TdT was positive in 4.9% of AMLs. Hybrid leukemias were 8 cases out 61 AML cases and were mainly composed of monocytic lineage, M4 and M5a. Myeloid markers detected in ALL were CD13 2.2% and CD33 2.2%. In this study, immunologically classified ALLs were composed of 65.2% of CALLA (+) B precursor type, 10.9% of CALLA (-) B precursor pattern, 8.7% of T cell type, 2.2% of B cell type, 4.5% of mixed lymphoid lineage(B&T), 2.2% of undifferentiated leukemia, and 6.5% of hybrid leukemia. Twelve cases of acute leukemias ware finally diagnosed to be 5 cases of hybrid leukemia, 3 cases of B lineage, 3 case of T lineage and 1 case of mixed lymphoid(B&T) leukemia. In summary, we think the best method for typing acute leukemias is by using a combination of FAB classification and immunophenotying.

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Survey of antibody on Orientia Tsutsugamushi among wild rodents in Gyeongnam area and detection by nested polymerase chain reaction (경남지역 야생들쥐에서 Orientia tsutsugamushi에 대한 항체 조사 및 PCR에 의한 검색)

  • Hah, Dae-Sik;Kim, Young-Hoon;Park, Jung-Ung;Park, Jae-Kap;Kim, Chung-Hui;Ryu, Jae-Doo;Jong, Myung-Ho;Heo, Jung-Ho;Shu, Jong-Lip;Cho, Myung-Heui;Lee, Kuk-Cheon;Kim, Gon-Sup;Kim, Eui-Kyung;Kim, Jong-Shu
    • Korean Journal of Veterinary Research
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    • v.44 no.2
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    • pp.241-249
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    • 2004
  • As a part of epidemiologic investigation of tsutsugamushi disease, the wild rodents which were captured in Gyeongnam area were diagnosed with indirect immunofluorescent antibody assay (IFA) and Polymerase Chain Reaction (PCR) to find if they have an antibody against Orientia tsutsugamushi. The conclusion was drawn as followings. (1) The captured 58 wild rodents showed that the subspecies distribution of Apodemus agrarius was 86.2%, Microtus fortis was 8.6% and Crocidura lasiura was 5.2%. (2) The antibody positive rate of O. tsutsugamushi Gilliam, Karp, Karto and Boryong by IFA method was 32.0% in Apodemus agrarius among 50 wild rodents and 40.0% in Microtus fortis among 5 wild rodents, respectively. It was negative in the case of all the 3 Crocidura lasiura. (3) The antibody titers on Apodemus agrarius, Microtus fortis and Crocidura lasiura against Gilliam, Karp, Karto and Boryong were measured between 1:20 and 1:640. The antibody titer against each antigen was in the order Boryong>Gilliam>Karp. (4) O. tsutsugamushi was detected from the blood, spleen and kidney from the artificially infected mice by IFA and PCR. IFA showed the positive response between 3 and 18 days after inoculation. On the other hand, positive response was found from all the samples by PCR. (5) From PCR of the genomic DNA extracted from the blood, spleen and kidney samples of the captured wild rodents, Boryong-specific amplification product with size of 210 bp, which is particular in Boryong, was detected from spleen and kidney samples, but not detected in the blood. (6) Boryong-specific amplification product was detected from spleen and kidney samples which were obtained at 3, 6, 12, 18 and 24 days after the infection with Boryong. But, it wasn't detected from the uninfected samples. (7) From PCR of spleen and kidney samples of the captured wild rodents, it was found that positive rate of O. tsutsugamushi in Apodemus agrarius and Microtus fortis were 25.0% (4/16) and 20.0% (1/5), respectively. From the above results, it can be concluded that Apodemus agrarius resided in Gyeongnam area carried O. tsutsugamushi and PCR method might be a simple, precise, rapid and useful diagnostic tool than IFA for the diagnosis of O. tsutsugamushi.

Studies on Pathogenicity of Nosema bombycis Naegeli to Parents and Hybrid in the Silkworm (Bombyx mori L.) (원종 및 교잡종에 대한 미립자의 병원성에 관한 연구)

  • 김종수;김문협;채수군;임종성
    • Journal of Sericultural and Entomological Science
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    • v.14 no.2
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    • pp.81-92
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    • 1972
  • Studies on Pathogenicity of Nosema bombycis Naegeli are summarized as follows: 1. The mortality of the parents, Jam 103 and Jam 104, is remarkbly higher than that of the hybrid, Jam 103$\times$Jam 104, whereas there is no difference in the mortality between the parents. 3. In the mortality of the pathogen-concentration, it is increased in order of the following concentrations inoculated, 10$^{8}$ , 10$^{7}$ , 10$^{8}$ and 10$^{5}$ /ml. 3. In the mortality of each instar, it is high in order of 5th, 4th, 3rd, and 2nd instar. 4. In the interaction between the mortalities of the varieties and the concentrations, 1) The mortality shows no differences between the parents and the hybrid in the high concentration of 10$^{8}$ /ml. 2) The mortality of the hybrid is lower than that of the parents in the low concentration of 10$^{5}$ /ml, whereas no difference is found between the parents. 3) The interaction appears at the same level in the middle concentration of 10$^{6}$ /ml to the parents and of 10$^{7}$ /ml to the hybrid. 5. It was pointed out that active immunity depends upon the volume of antigen injection, immunizing period, and injection intervals. In this experiment, it is noticed that the optimum volume of injection is above 20ml and D is the best one of the four treatment (A.B.C.D.). 6. The immune sera indicate such a 12,800 high titer in the indirect method can be obtained from the D immunizing method. Silkworm tissues and N. bombycis spores show self-fluorescence, but it is able to distinguish it from the F.I.T.C. by using the U.V. filter. 7. The midgut epithelium is examined to be the first site of the tissues which are penetrated into and multiplied by the inoculation of the pathogen per os.

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Effects of Storytelling in Advertising on Consumers' Empathy

  • Park, Myungjin;Lee, Doo-Hee
    • Asia Marketing Journal
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    • v.15 no.4
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    • pp.103-129
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    • 2014
  • Differentiated positioning becomes increasingly difficult when brand salience weakens. Also, the daily increase in new media use and information load has led to a social climate that regards advertising stimuli as spamming. For these reasons, the focus of advertisement-related communication is shifting from persuading consumers through the direct delivery of information to an emphasis on appealing to their emotions using matching stimuli to enhance persuasion effects. Recently, both academia and industry have increasingly shown an interest in storytelling methods that can generate positive emotional responses and attitude changes by arousing consumers' narrative processing. The purpose of storytelling is to elicit consumers' emotional experience to meet the objectives of advertisement producers. Therefore, the most important requirement for storytelling in advertising is that it evokes consumers' sympathy for the main character in the advertisement. This does not involve advertisements directly persuading consumers, but rather, consumers themselves finding an answer through the advertisement's story. Thus, consumers have an indirect experience regarding the product features and usage through empathy with the advertisement's main character. In this study, we took the results of a precedent study as the starting point, according to which consumers' emotional response can be altered depending on the storytelling methods adopted for storytelling ads. Previous studies have reported that drama-type and vignette-type storytelling methods have a considerably different impact on the emotional responses of advertising audiences, due to their different structural characteristics. Thus, this study aims to verify that emotional response aroused by different types of advertisement storytelling (drama ads vs. vignette ads) can be controlled by the socio-psychological gender difference of advertising audiences and that the interaction effects between the socio-psychological gender differences of the audience and the gender stereotype of emotions to which advertisements appeal can exert an influence on emotional responses to types of storytelling in advertising. To achieve this, an experiment was conducted employing a between-group design consisting of 2 (storytelling type: drama ads vs. vignette ads) × 2 (socio-psychological gender of the audience: masculinity vs. femininity) × 2 (advertising appeal emotion type: male stereotype emotion vs. female stereotype emotion). The experiment revealed that the femininity group displayed a strong and consistent empathy for drama ads regardless of whether the ads appealed to masculine or feminine emotions, whereas the masculinity group displayed a stronger empathy for drama ads appealing to the emotional types matching its own gender as well as for vignette ads. The theoretical contribution of this study is significant in that it sheds light on the controllability of the audiences' emotional responses to advertisement storytelling depending on their socio-psychological gender and gender stereotype of emotions appealed to through advertising. Specifically, its considerable practical contribution consists in easing unnecessary creative constraints by comprehensively analyzing essential advertising strategic factors such as the target consumers' gender and the objective of the advertisement, in contrast to the oversimplified view of previous studies that considered emotional responses to storytelling ads were determined by the different types of production techniques used. This study revealed that emotional response to advertisement storytelling varies depending on the target gender of and emotion type appealed to by the advertisement. This suggests that an understanding of the targeted gender is necessary prior to producing an advertisement and that in deciding on an advertisement storytelling type, strategic attention should be directed to the advertisement's appeal concept or emotion type. Thus, it is safe to use drama-type storytelling that expresses masculine emotions (ex. fun, happy, encouraged) when the advertisement target, like Bacchus, includes both men and women. For brands and advertisements targeting only women (ex. female clothes), it is more effective to use a drama-type storytelling method that expresses feminine emotions (lovely, romantic, sad). The drama method can be still more effective than the vignette when women are the main target and a masculine concept-based creative is to be produced. However, when male consumers are targeted and the brand concept or advertisement concept is focused on feminine emotions (ex. romantic), vignette ads can more effectively induce empathy than drama ads.

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A Study on the Effect of Healing Experience Program on Satisfaction: Focused on Experience Cost and Experience Time (치유체험프로그램이 만족도에 미치는 영향에 관한 연구: 체험비용과 체험시간을 중심으로)

  • An, Hye-Jung;Kan, Soon-Ah
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.17 no.3
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    • pp.183-200
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    • 2022
  • This study is a study on the effect of a healing experience program on satisfaction in the field of healing agriculture. In the development of a rural experience program, what factors constituting the healing experience program affect satisfaction, and how much time and participation cost affect the satisfaction of the healing experience program from the marketing point of view of the healing experience program. I want to analyze By researching the effect of experience cost and experience time on satisfaction of the healing experience program, I would like to suggest the development direction of the healing experience program. To this end, by empirically analyzing the effect of a healing experience program using experience cost and experience time as parameters on satisfaction, we present a theoretical basis for priority considerations when developing a rural experience program. There are entertainment experience, educational experience, deviant experience, and aesthetic experience as sub-factors of the experience program, experience time and experience cost as parameters, and satisfaction as a dependent variable. In addition, the reliability of the research results was secured by setting the demographic variables of the survey subjects as control variables. The empirical analysis was conducted on 314 valid questionnaires from the unspecified majority who were interested in or aware of the healing experience program. SPSS v22.0 was used, and to test the mediating effect, the three-step verification method of Baron & Kenny(1986) and the SPSS PROCESS Macro Model No. of Andrew F. Hayes(2018). 4 The reliability of the mediating effect was secured by applying the verification method and comparing the analysis resul. As a result of the study, it was found that educational experience (𝛽=.134, t=1.759*) had a positive (+) effect on experience cost, and aesthetic experience (𝛽=.144 t=1.684*) had a positive (+) effect on experience time. +) was found to have an effect. Also, educational experience (𝛽=.239, t=4.112***) was found to have a positive (+) effect on satisfaction, and aesthetic experience (𝛽=.330 t=4.921***) had a positive effect on satisfaction. It has been shown to have a (+) effect. Experience time was found to have a negative (-) inconsistent mediating effect between aesthetic experience and satisfaction. That is, it is the total effect (𝛽=.330 t=4.921***), and the direct effect (𝛽=.349 t=5.241***) increased by 𝛽=.019 compared to the total effect when the experience time was input, while the indirect effect (𝛽=-.019), which was shown to exert a negative (-) mediating effect.

Epidemiology and Clincal Analysis of Acute Viral Respiratory Tract Infections in Children(September, 1998-May, 2003) (소아 급성 바이러스성 하기도 감염의 유행 및 임상양상 (1998년 9월-2003년 5월))

  • Lee, Su-Jin;Shin, Eon-Woo;Park, Eun-Young;Oh, Pil-Soo;Kim, Kwang-Nam;Yoon, Hae-Sun;Lee, Kyu-Man
    • Clinical and Experimental Pediatrics
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    • v.48 no.3
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    • pp.266-275
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    • 2005
  • Purpose : Acute respiratory tract infections are the most common illnesses in children. The great majority of these infections involving lower respiratory tracts infections(LRTIs) are caused by respiratory viruses such as respiratory syncytial virus(RSV), parainfluenza virus(PIV), influenza virus (Flu), and adenovirus(ADV), etc. Our purpose was to determine seasonal epidemiology and clinical characteristic features of each viral infection. Methods : Nasopharyngeal aspirate(NPA)s were collected from 4,554 hospitalized children diagnosed as LRTIs on the first day of admission. The study period was from September 1998(Autumn) through May 2003(Spring). Respiratory viruses were detected in 881(19 percent) cases by isolation of the virus or by antigen detection method using indirect immunofluorescent staining. We reviewed the medical records of 837 cases retrospectively. Results : The identified pathogens were RSV in 485 cases(55 percent), PIV in 152 cases(17 percent), FluA in 114 cases(13 percent), ADV in 79 cases(9 percent) and FluB in 51 cases(6 percent). Outbreaks of RSV occurred every year, mostly in the November through December period and of PIV in the April through June period. LRTIs by FluA reached the highest level in January, 2002. FluB infection showed an outbreak in April, 2002. The clinical diagnoses of viral LRTIs were bronchiolitis in 395 cases(47 percent), pneumonia in 305 cases(36 percent), croup in 73 cases(9 percent) and tracheobronchitis in 64 cases(8 percent). Conclusion : Viruses are one of the major etiologic agents of acute LRTIs in chidren. Therefore, we must continue to study their seasonal occurrence and clinical features to focus on management, and also for reasons of prevention.