• 한방안이비인후피부과학회지
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• 제23권2호
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• pp.27-40
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• 2010

Background and Objective : Increasing interest in anti-aging and anti-wrinkling agents for the skin has triggered the recent outflow of researches and studies in this field. This study was designed to investigate the effects of bee venom on skin wrinkling and skin aging by testing the skin wrinkling, skin elasticity, trans-epidermal water loss (TEWL), free radical level, anti-oxidative agent level, and skin tissue after infusion of bee venom on hairless mouse. Materials and Methods : Fifteen hairless mice aged between 36~40 weeks were divided randomly into 3 Group; the Bee Venom Syringe Group, the Bee Venom Needle Group, and the control group. The Bee Venom Syringe Group were injected subcutaneously with bee venom (0.1cc in total) using an insulin syringe on three spots in the lumbar spine (one spot on the center and two spots 1~2cm to the side bilaterally). The Bee Venom Needle Group were pricked with bee venom-smeared acupuncture needles on three longitudinal spots in the lumbar spine each 1cm apart, after which the needles were removed 10 minutes later. The Control Group did not receive any form of intervention. All procedures took place thrice a week for four weeks, during which the mice were allowed free access to water and fodder. The mice were measured and compared in the weight, skin wrinkling scale, skin elasticity, and TEWL before and after the experiment. After the experiment, blood samples were taken to measure the free radical and anti-oxidative agent level, and the skin tissue was sliced for examination. Data was analyzed using the SPSS program (ver 12.0). The ANOVA analysis was used to compare and contrast the three groups, and t-test for paired samples was used to evaluate skin-wrinkling before and after experiment. The cut-off p-value of significance was set at p<0.05. Results : 1. Administration of bee venom did not cause serious weight loss or gain. 2. Compared to the control group, the Bee Venom Syringe Group and the Bee Venom Needle Group both showed a decrease in skin wrinkling scale after intervention. Especially, the Bee Venom Syringe Group showed a significant decrease (p<0.05). 3. Compared to the control group, the Bee Venom Syringe Group and the Bee Venom Needle Group both showed an increase in skin elasticity. Especially, the Bee Venom Syringe Group showed a significant increase (p<0.05). 4. No significant change in TEWL was found in the mice in all the three groups before and after experiment. 5. Free radical level was normal in all 15 mice in all the three groups, and anti-oxidative agent was not significantly different across the three groups. 6. The Bee Venom Syringe Group, the Bee Venom Needle Group, and the control group did not show any significant difference in the thickness of epidermis and dermis, infiltration of inflammatory cells, and skin wrinkling. The epidermis layer was relatively better preserved in the Bee Venom Syringe Group as compared to the Bee Venom Needle Group and the control group. Conclusion : Direct injection of bee venom on the hairless mouse using a syringe was found to improve wrinkling of the skin and increase skin elasticity but did not show effectiveness on skin dryness due to water loss. The bee venom appears to have suppressive effects on skin wrinkling, one of the symptoms of skin aging, through a process independent of suppression of free radicals or increase of anti-oxidative agent.

• Asian Pacific Journal of Cancer Prevention
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• 제16권18호
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• pp.8653-8658
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• 2016

Background: Heparanase is believed to be involved in gastric carcinogenesis. However, the clinicopathologic features of gastric cancer with high heparanase expression remain unclear. Aim : The purpose of this study was to comprehensively and quantitatively summarize available evidence for the use of heparanase mRNA and protein expression to evaluate the clinicopathological associations in gastric cancer in Asian patients by meta-analysis. Materials and Methods: Relevant articles listed in MEDLINE, CNKI and the Cochrane Library databases up to MARCH 2015 were searched by use of several keywords in electronic databases. A meta-analysis was performed to clarify the impact of heparanase mRNA and protein on clinicopathological parameters in gastric cancer. Combined ORs with 95%CIs were calculated by Revman 5.0, and publication bias testing was performed by stata12.0. Results: A total of 27 studies which included 3,891 gastric cancer patients were combined in the final analysis. When stratifying the studies by the pathological variables of heparanase mRNA expression, the depth of invasion (633 patients) (OR=4.96; 95% CI=2.38-1.37; P<0.0001), lymph node metastasis (639 patients) (OR=6.22; 95%CI=2.70-14.34, P<0.0001), and lymph node metastasis (383 patients) (OR=6.85; 95% CI=2.04-23.04; P=0.002) were all significant. When stratifying the studies by the pathological variables of heparanase protein expression, this was the case for depth of invasion (1250 patients) (OR=2.76; 95% CI=1.52-5.03; P=0.0009), lymph node metastasis (1178 patients) (OR=4.79 ; 95% CI=3.37-6.80, P<0.00001), tumor size (727 patients) (OR=2.06 ; 95% CI=1.31-3.23; P=0.002) (OR=2.61; 95% CI=2.09-3.27; P=0.000), and TNM stage (1233 patients) (OR=6.85; 95% CI=2.04-23.04; P=0.002). Egger's tests suggested publication bias for depth of invasion, lymph node metastasis, lymph node metastasis and tumor size of heparanase mRNA and protein expression. Conclusions: This meta-analysis suggests that higher heparanase expression in gastric cancer is associated with clinicopathologic features of depth of invasion, lymph node metastasis and TNM stage at mRNA and protein levels, and of tumor size only at the protein level. Egger's tests suggested publication bias for these clinicopathologic features of heparanase mRNA and protein expression, and which may be caused by shortage of relevant studies. As a result, although abundant reports showed heparanase may be associated with clinicopathologic features in gastric cancer, this meta-analysis indicates that more strict studies were needed to evaluate its clinicopathologic significance.

• 대한간호학회지
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• 제20권3호
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• pp.324-340
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• 1990

Support has always been considered an important nursing concept. However, there is no agreement among nurse researchers as to a conceptual definition of supportive nursing or meaningful supportive behaviors. Clarification of the concept, support in nursing, is necessary to promote communication among nurses on nursing behaviors that are effective in providing support and on understanding the relevant properties and charcteristics of the concept, supportive nursing care. The objectives of the study were : 1. to analyse the concept, support in nursing, in order to provide a definition of supportive nursing care, and 2. to operationalize the definition of supportive nursing care and use it as an experimental nursing intervention for patients with low back pain. The first part of the study used the concept analysis approach developed by Walker and Avant(1983) to define the concept of supportive nursing care. The properties of supportive nursing care, defined by this analysis, included perception of supportive need, reciprocal interaction(Transaction), listening, providing empathy and information related to health, and confirmation of the patient's verbal and non - verbal response. The second part, the experimental part of the study, was done using King's(1970) Interpersonal Theory for Nursing. The concept, supportive nursing care, as defined in the concept analysis was operationalized and used as the experimental intervention. The experiment tested the effectiveness of the independent variable, supportive nursing care on the dependent variables, depression, mood and patient satisfaction, in the patients with low back pain in army hospitals. The instruments used to measure the dependent variables were Zung's(1965) Self- Rating Depression Scale, Ryman and Colleagues'(1974) Mood Questionnaire and LaMonica and Colleagues'(1986) Patient Satisfaction Scale. The experimental design used for this study was a Solomon 4 group experimental design. This design has the strength of allowing for observation of the main effects of supportive nursing care and pretesting, and for observation of the interaction effects of pretesting and supportive nursing care. The design includes one experimental group and three control groups. The Subjects of this study were 150 young male patients with low back pain on Neuro - Surgical Wards in three general army hospitals. There were 35 in the experimental group, 39 in the pre - posttest control group, 36 in the treatment - posttest control group and 40 in the posttest only control group. Supportive nursing care, as operationalized by the researcher according to the concept analysis, was given to the patients in the experimental group and the treatment -posttest control group, individually for 30 minute sessions, every other day for 5 days. Data collection was done using a questionnaire. The data were collected in a pretest one week before the supportive nursing care sessions, a posttest immediately after the sessions and follow- up test one week later. Hypotheses testing was done using 2×2 factorial analysis of variance and Meta analysis(Stouffer's Z method). The results of this study are summarized as follows : 1. Hypothesis Ⅰ, “There will be a difference on depression level between the patients with low back pain who receive supportive nursing care and those who do not receive supportive nursing care”, was supported (F＝8.49, p＜.05). 2. Hypothesis Ⅱ, “There will be a difference on mood level between the patients with low back pain who receive supportive nursing care and those who to not receive supportive nursing care”, was supported (Z meta＝2.17, p＜.05). 3. Hypothesis Ⅲ, “There will be a difference on satisfaction level between the patients with low back pain who receive supportive nursing care and those who do not receive supportive nursing care”, was supported (F＝13.67, p＜.05). 4. ANOVA, done to examine the interaction effect of history and maturation, showed no significant difference on the dependent variables between the observations of the pretest scores of the experimental group, the pretest scores of the pre- posttest control group and the posttest score of the posttest only control group. 5. To test for continuing effect of supportive nursing care, paired t-test was done to compare the scores for the dependent variables at the posttest and at the one week later follow-up test. No significant difference on the scores for the dependent variables was found between the posttest scores and the follow-up test scores for the two groups that received supportive nursing care, the experimental group and the treatment-posttest control group. In conclusion, it was found that in the case of young soldiers with low back pain in army hospitals, their depression level was decreased, their mood state was changed positively and their satisfaction level was increased by receiving supportive nursing care. Further, the effectiveness of the supportive nursing care lasted for at least one week in this study. The significance of this study to nursing is in the analysis of the concept of supportive nursing care and the demonstration of the effectiveness of supportive nursing care as an intervention within the limits of the study.

• 근관절건강학회지
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• 제8권1호
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• pp.122-140
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• 2001

The aims of this study were to understand and to predict the determinent factors affecting the exercise behaviors and physical fitness by testing the Pender's revised health promotion model, and to help the patients with rheumatoid arthritis and osteoarthritis perform the continous exercise program, and to help them maximize the physical effect such as muscle strength, endurance, and functional status and mental effects including self efficacy and quality of life, and improve the physical and mental well being, and to provide a basis for the nursing intervention strategies. Of the selected variables in this study, the endogenous variables included the physical fitness, exercise score, exercise participation, perceived benefits of action, perceived barriers of action to exercise, activity-related affect(depression) and perceived self-efficacy, interpersonal influences(family support), situational factors(duration of arthritis, fatigue) and the exogenous variables included personal sociocultural factor(education level), personal biologic factor(body mass index), personal psychologic factor(perceived health status) and prior related behavior factors(previous participation in exercise, life-style). We analyzed the clinical records of 208 patients with rheumatoid arthritis and degenerative arthritis who visited the outpatient clinics at H university hospital in Seoul. Data were composed of self reported qustionnaire and good of fitness score which were obtained by padalling the ergometer of bicycle for 9 minutes. SPSS Win 8.0 and Window LISREL 8.12a were used for statistical analysis. Of 75 hypothetical paths that influence on physical fitness, exercise participation, exercise score, perceived benefits of action, perceived barriers of action to exercise, activity-related affect(depression) and perceived self-efficacy, interpersonal influences(family support), situational factors(duration of arthritis, fatigue), 40 were supported. The physical fitness was directly influenced by life-style, perceived health status, education level, family support, fatigue, which explained 12% of physical fitness. The exercise participation were directly influenced by life-style, education level, past exercise behavior, perceived benefits of action, perceived barriers of action, depression and duration of arthritis, which explained 47% of exercise participation. Exercise score were directly affected by perceived self efficacy. BMI, life-style, past exercise behavior, perceived benefits of action, family support, perceived health status. perceived barriers of action, and fatigue, which explained 70%. Perceived benefits of action was directly influenced by BMI, life-style, which explained 39%. Perceived barriers of action were directly influeced by past exercise behavior, perceived health status, which explained 7%. Perceived self efficacy were directly influeced by level of education, perceived health status, life-style, which explained 57%. Depression were directly influeced by past exercise behavior, BMI, life-style, which explained 27%. Family support were directly influeced by life-style, perceived health status, which explained 29%. Fatigue were directly influeced by BMI, life-style, perceived health status. which explained 41%. Duration of arthritis were directly influeced by life-style, past exercise behavior, BMI, which explained 6%. In conclusion, important variables for physical fitness were life-style, and variable affecting exercise participation were life-style. Perceived self-efficacy of exercise was a significant predictor of exercise score. BMI, Life-style, perceived benefits of action, family support, past exercise behavior showed direct effects on perceived self-efficacy. Therefore, disease related factor should be minimized for physical performance and well being in nursing intervention for patients with rheumatoid arthritis, and plans to promote and continue exercise should be seeked to reduce disability. In addition, Exercise program should be planned and performed by the exact evaluation of exercise according to the ability of the patients and the contents to improve the importance of exercise and self efficacy in self control program, dedicated educational program should be involved. This study suggest that the methods to reduce the disease related factors, the importance of daily life-style, recognition of benefit of exercise, and educational program to promote self efficacy should be considered in the exercise behavior promotion and nursing intervention for continous performance. The significance of this study is also thought to provide patients with chronic arthritis the specific data for maximal physical and mental well being through exercise, chronic therapeutic procedure, daily adaptation and confrontation in nursing intervention.

• 한국산림과학회지
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• 제29권1호
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• pp.102-114
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• 1976

소나무속(屬) Diploxylon아속(亞屬)의 종간잡종(種間雜種)인 일대잡종(一代雜種) ${\times}$ P. rigitaeda와 여교잡종(戾交雜種)인 ${\times}$ P. rigida rigitaeda와 ${\times}$ P. rigitaeda rigida, ${\times}$ P. rigitaeda의 $F_2$ 및 자연잡종(自然雜種)인 ${\times}$ P. rigitaeda Wind등(等)의 임성종자확득율(稔性種子穫得率)을 기준(基準)으로 한 교배친화력(交配親和力)과 분류학상(分類學上)의 유연관계(類緣關係)를 검토(檢討)하는 동시(同時)에 조림지(造林地)에 있어서의 생장비교(生長比較), 침엽(針葉)의 해부형태비교(解剖形態比較), phenol성(性) 물질(物質)에 의(依)한 특성비교(特性比較) 및 isoperoxidase의 변이비교등(變異比較等)을 구명(究明)하여 금후계획적조림(今後計劃的造林)에 공헌(貢獻)할 잡종채종림조성(雜種採種林造成) 여부(與否)와 우량잡종간(優良雜種間) 및 기량친종간(其兩親種間)의 차이점(差異點)을 분별(分別) 관찰(觀察)한 결과(結果) 다음과 같은 성적(成績)을 얻었다. 1. 각공시수종(各供試樹種)을 Shaw, Pilger 및 Duffield등(等)의 분류식(分類式)에 준(準)하여 각조합별(各組合別) 임성종자확득율(稔性種子穫得率)을 기준(基準)으로 교배친화력(交配親和力)과 유연관계(類緣關係)를 검토(檢討)한바 각조합(各組合)의 양친종간(兩親種間)에는 상당(相當)한 교배친화력(交配親和力)이 있었고, 근연간(近緣間)임을 알 수 있었으며, 각조합별(各組合別) 최고임성종자확득율(最高稔性種子穫得率)은 67~87%이었다. 2. 각조림지(各造林地)에서의 수고(樹高) 및 근시경(根元徑) 생장비교(生長比較)에서 수종간(樹種間)에 1~5% 수준(水準)으로 고도(高度)의 유의성(有意性)이 있었으므로 재적비(材積比)에서도 P. rigida 보다 28~80%의 보다 월등(越等)한 생장(生長)을 보여 조림상(造林上) 유용성(有用性) 가치(價値)가 있는 우수잡종(優秀雜種)으로 기대(期待)되며, ${\times}$ P. rigitaeda를 제외(除外)한 잡종송(雜種松)은 내한성(耐寒性)에 있어서 P. rigida의 형질(形質)을 받어 전연(全然) 동해(凍害)를 받지 않았으므로 내한력(耐寒力)이 강(强)함을 알 수 있었다. 3. 침엽(針葉)의 해부형태(解剖形態)에 있어서 제형질중(諸形質中) 일부(一部) 예외(例外)도 있었으나 각잡종송(各雜種松)은 대부분(大部分)이 hypoderm에서 biform이었고, resin canal에서는 중위(中位)를 나타냈으며, fibrovascular bundle에서는 대부분(大部分)이 양친종(兩親種)의 중간형질(中問形質)을 나타냈으므로 각잡종(各雜種)과 그 양친종간(兩親種間)의 식별(識別)은 어느정도(程度) 가능(可能)함을 보았다. 4. Phenol성물질(性物賢)에 의(依)한 특성비교(特性比較)에서 각공시잡종(各供試雜種)이 P. rigida와 공(共)히 Rf値 0.66인 phenol물질(物質) 7번(番)이 담황색(淡黃色)으로 반응(反應)되었으나 P. taeda에는 반응(反應)이 나타나지 않았으므로 양친종간(兩親種間)에는 현저(願著)한 식별(識別)을 할 수 있었다. 5. 과산화(過酸化) 동위효소형(同位酵素型)의 변이(變異)는 각공시수종(各供試樹種)에 출현(出現)된 band의 수(數)와 위치(位置) 및 활성도(活性度)의 차이(差異)가 상이(相異)하므로 어느정도(程度) 식별(識別)이 가능(可能)함을 알 수 있었다.

• 대한핵의학회지
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• 제28권2호
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• pp.177-185
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• 1994

Pharmacologic coronary vasodilation in conjunction with myocardial perfusion scintigraphy has become an alternative to dynamic exercise test for the diagnosis and risk stratification of coronary artery disease, especially in patients who are unable to perform adequate exercise. Dipyridamole and adenosine have been used for pharmacologic stress testing with myocardial perfusion imaging. Adenosine is a potent coronary vasodilator with rapid onset of action, short half-life, near maximal coronary vasodilation and less serious side effects. ST segment depression has been reported in about 7-15% of patients with coronary artery disease receiving dipyridamole in conjunction with myocardial perfusion imaging. The exact cause and clinical significance are not known. In order to evaluate the relationship between adenosine-induced ST segment depression during $^{99m}Tc$-MIBI myocardial perfusion scintigraphy and the severity of coronary artery disease, we performed $^{99m}Tc$-MIBI imaging after intravenous Infusion of adenosine In 120 patients with suspected coronary artery disease. Of the 120 patients, 28 also performed coronary angiography. There were 24 patients with ST segment depression during $^{99m}Tc$-MIBI scintigraphy and 96 patients without ST segment depression. Adenosine was infused Intravenously at a dose of 0.14mg/kg per minute lot 6minutes and $^{99m}Tc$-MIBI was injected at 3 minute. We then com-pared the hemodynamic changes, side effects, scintigraphic and angiographic findings. Heart rate increased $90{\pm}19$ beats/minute in the group with ST depression compared with $80{\pm}16$ beats/minute in the group without ST depression(p<0.05). Baseline systolic blood pressure was significantly higher in the group with ST depression($152{\pm}27$ mmHg) than in the group without 57 depression($140{\pm}21$mmHg, p<0.05). Double product at baseline($10.90{\pm}2.77$ versus $9.55{\pm}2.34\;beats/minute{\times}mmHg$) and during adenosine infusion($12.72{\pm}3.89$ versus $10.83{\pm}2.98\;beats/minute{\times}mmHg$) were significantly higher in the group with ST depression(p<0.05). The incidence of anginal chest pain was also significantly higher in the group with ST depression(ST versus 29%, p<0.0001). The $^{99m}Tc$-MIBI images were abnormal in 23(96%) patients with ST segment depression and 66(69%) patients without ST segment depression(p<0.05). In patients with ST segment depression, there were more reversible perfusion defects than in patients without ST segment depression(83 versus 55%, p<0.05). The number of abnormal segments were significantly higher in the group with ST depression($3.05{\pm}2.01$ versus $1.51{\pm}1.45$, p<0.005). In patients with ST segment depression, there were more segments of reversible perfusion defects than in patients without segment depression($2.15{\pm}2.11$ versus $0.89{\pm}1.24$, p<0.05). There were no differences in the angiographic severity by vessel(p ; NS). We concluded that ST segment depression during $^{99m}Tc$-MIBI myocardial perfusion scintigraphy with Intravenous adenosine is related to the severity of coronary artery disease.

• 구강회복응용과학지
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• 제36권3호
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• pp.183-195
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• 2020

목적: 이 논문의 목적은 CAD/CAM 의치상 레진과 열중합 의치상 레진의 굴곡 강도를 비교해보고, 두께에 따른 굴곡 강도 변화도 비교해보는 것이다. 연구 재료 및 방법: 열중합 의치상 레진은 Lucitone 199^® (C-LC)을 사용하였다. 3D printing 의치상 레진으로는 DIOnavi - Denture (P-DO)와 DENTCA - Denture Base II (P-DC)를 사용하였다. 밀링 PMMA 블록으로는 Vipi Block Gum (M-VP)과 M-IVoBase^® CAD (M-IV)를 사용하였다. 시편의 최종 규격은 65.0 mm × 12.7 mm × 1.6 mm / 2.0 mm / 2.5 mm였다. 굴곡 강도와 굴곡 탄성율을 측정하기 위해 3점 굽힘 시험을 실시하였다. 그리고 파절된 시편의 단면을 주사전자현미경 (SEM) 을 사용하여 분석하였다. 데이터의 정규성을 확인한 뒤 일원분산분석(one-way ANOVA)을 사용하여 유의 수준 P = 0.05로 설정하여 그룹 간의 차이를 평가한 뒤, 사후 분석을 위해 Tukey HSD test를 시행하였다. 결과: 동일 두께 내에서, P-DO를 제외한 나머지 CAD/CAM 의치상 레진들과 열중합 의치상 레진의 굴곡 강도는 유의한 차이를 나타내었다. M-VP는 열중합 의치상 레진 보다 굴곡 강도가 높게 나타났고, P-DC와 M-IV는 낮은 굴곡 강도를 보였다. 굴곡 탄성률은 M-VP에서 제일 높게 나타났고 C-LC, P-DO, P-DC, M-IV 순으로 낮아졌으며 재료간에 모두 유의한 차이가 나타났다. 두께에 따른 굴곡 강도는, C-LC에서는 2.5 mm가 1.6 mm보다 유의하게 높은 굴곡 강도를 보였고, P-DC, M-VP는 2.5 mm와 2.0 mm에서 1.6 mm보다 유의하게 높은 굴곡 강도가 나타났다. M-IV에서는 두께가 증가할수록 유의한 굴곡 강도 증가가 나타났다. SEM 분석 결과 서로 다른 재료들의 파절된 단면은 각기 다른 양상을 띄었다. 결론: 본 연구에서 사용된 CAD/CAM 의치상 레진의 굴곡 강도는 각 재료의 성분 및 특성에 따라 다양하게 나타났다. CAD/CAM 의치상 레진의 굴곡 강도는 두께가 감소하여도 1.6 mm 이상의 두께에서는 ISO 20795-1:2013에서 제시하는 굴곡 강도보다 높게 나타났다. 하지만 보다 얇은 두께의 의치를 임상적으로 사용하기 위해서는, 더 낮은 두께의 의치상 레진의 다른 특성들에 관한 추가적인 연구가 필요하다.

• 구강회복응용과학지
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• 제35권2호
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• pp.72-80
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• 2019

목적: 본 연구의 목적은 레진계 치아고정 재료의 법랑질 치면 처리 방법에 따른 전단결합강도와 파절 양상을 비교 분석하는 것이다. 연구 재료 및 방법: 레진계 치아고정 재료로 G-FIX, LightFix를 사용하였다. 시편 제작을 위해 소의 하악 절치 20개를 사용했다. 노출된 법랑질 표면을 4부분으로 구분하여, 각 분획 마다 37% 인산(E), 37% 인산+Adhesive resin (E+A), 37% 인산+G-premio bond (E+GP), G-premio bond (GP)로 각각의 치면 처리를 하고, 재료를 접착하였다. 만능 시험기를 이용하여 전단결합강도를 측정하였고, 시편의 파절된 표면을 현미경으로 확대하여 파절 양상을 관찰하였다. Two-way ANOVA를 이용하여 재료와 표면처리 방법 사이의 상호작용을 검증하였고 각 재료에서 표면처리 방법 사이의 비교를 위해 One-Way ANOVA test를 하고 Scheffe's test로 사후 검정 하였다. 각 표면처리 방법에서 재료 사이의 전단결합강도를 비교하기 위해 independent t-test를 하였다. 모든 통계는 95% 유의수준에서 진행하였다. 결과: 동요치 고정을 위한 G-FIX는 산부식만 시행한 후 재료를 적용해도 접착 레진을 추가적으로 사용했을 때와 유사한 전단결합강도를 보였으며 LightFix는 산부식을 시행한 후 접착 레진을 추가적으로 사용했을 때 가장 높은 전단결합강도를 보였다. 또한, G-FIX와 LightFix 모두에서 별도의 산부식 없이 자가부식 접착제만 처리했을 때 가장 낮은 전단결합강도를 보였다. 교호작용의 검증 결과 치아고정용 레진과 표면처리 방법 사이의 상호 연관됨이 관찰되었다. 파절 양상은 모든 군에서 대부분 혼합성 파절이 관찰되었다. 결론: 치아 고정용 레진인 G-FIX와 LightFix의 사용시 제조사의 지시와 같이 산부식만 시행한 후 재료를 적용해도 충분한 접착이 이루어질 것으로 생각된다.

• 정보관리학회지
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• 제36권1호
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• pp.137-168
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• 2019

이 연구의 목적은 대학도서관 이용자의 공동체의식과 대학도서관 서비스품질 평가, 이용자만족도 및 충성도를 측정 및 분석하여 대학도서관 이용자의 공동체의식이 이용자만족도 및 충성도에 미치는 영향 관계를 규명하고자 한다. 이를 위해 연구모형과 연구가설을 설정하였다. 가설 검증을 위하여 J대학교 중앙도서관을 이용한 경험이 있는 학생들을 대상으로 최종 282부의 유효표본을 분석에 사용하였다. 측정변수들의 평균값을 기술통계량으로 분석하였으며, 가설 검증을 위해 Hayes의 PROCESS macro프로그램 모형 4번과 6번을 사용하여 매개효과분석을 실시하였다. 이 연구의 결과, 1) 대학도서관 이용자의 공동체의식은 대학도서관 서비스 품질평가에 따라 이용자만족도에 유의한 영향을 미치는 것으로 나타났다. 대학도서관 이용자의 공동체의식을 구성하는 요소인 서비스 혜택 지각 및 충족감, 상호영향의식이 통계적 유의수준 하에서 서비스 품질평가에 정(+)의 영향을 미치며, 이를 매개로 이용자만족도에 정(+)의 영향을 미치는 것으로 나타나, 대학도서관 이용자의 공동체의식이 높을수록 서비스 품질평가가 높으며, 이를 통해 이용자만족도가 높아진다는 것을 알 수 있었다. 2) 대학도서관 이용자의 공동체의식은 대학도서관 서비스 품질평가와 이용자만족도에 따라 이용자충성도에 유의한 영향을 미치는 것으로 나타났다. 대학도서관 이용자의 공동체의식을 구성하는 요소인 서비스 혜택 지각 및 충족감, 상호영향의식이 서비스 품질평가를 매개로 이용자만족도에 통계적으로 유의한 영향을 미치고(가설1), 이용자만족도를 매개로 통계적 유의수준 하에서 이용자충성도에 정(+)의 영향을 미치는 것으로 나타났다. 따라서, 대학도서관 이용자의 공동체의식이 높을수록 서비스 품질평가가 높고, 이용자만족도가 높아지며, 이를 통해 이용자충성도가 높아진다는 것을 확인할 수 있었다.

• 지능정보연구
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• 제28권2호
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• pp.237-262
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• 2022

본 연구는 개인투자자들의 투자의사결정에 도움을 주고자, 증권신고서의 TF-IDF 텍스트 분석과 기계학습을 이용해 공모주의 상장 5거래일 이후 주식 가격 등락을 예측하는 모델을 제시한다. 연구 표본은 2009년 6월부터 2020년 12월 사이에 신규 상장된 691개의 국내 IPO 종목이다. 기업, 공모, 시장과 관련된 다양한 재무적 및 비재무적 IPO 관련 변수와 증권신고서의 어조를 분석하여 예측했고, 증권신고서의 어조 분석을 위해서 TF-IDF (Term Frequency - Inverse Document Frequency)에 기반한 텍스트 분석을 이용해 신고서의 투자위험요소란의 텍스트를 긍정적 어조, 중립적 어조, 부정적 어조로 분류하였다. 가격 등락 예측에는 로지스틱 회귀분석(Logistic Regression), 랜덤 포레스트(Random Forest), 서포트벡터머신(Support Vector Machine), 인공신경망(Artificial Neural Network) 기법을 사용하였고, 예측 결과 IPO 관련 변수와 증권신고서 어조 변수를 함께 사용한 모델이 IPO 관련 변수만을 사용한 모델보다 높은 예측 정확도를 보였다. 랜덤 포레스트 모형은 1.45%p 높아진 예측 정확도를 보였으며, 인공신공망 모형과 서포트벡터머신 모형은 각각 4.34%p, 5.07%p 향상을 보였다. 추가적으로 모형간 차이를 맥니마 검정을 통해 통계적으로 검증한 결과, 어조 변수의 유무에 따른 예측 모형의 성과 차이가 유의확률 1% 수준에서 유의했다. 이를 통해, 증권신고서에 표현된 어조가 공모주의 가격 등락 예측에 영향을 미치는 요인이라는 것을 확인할 수 있었다.