• Tuberculosis and Respiratory Diseases
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• v.44 no.2
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• pp.280-289
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• 1997

Background : Bronchioloalveolar carcinoma (BAC) has been reported to diveres spectrum of chinical presentations and radiologic patterns. The three representative radiologic patterns are followings ; 1) a solitary nodule or mass, 2) a localized consolidation, and 3) multicentric or diffuse disease. While, the localized consolidation and solitary nodular patterns has favorable prognosis, the multicentric of diffuse pattern has worse prognosis regardless of treatment. BAC presenting as a solitary pulmonary nodule is often misdiagnosed as other benign disease such as tuberculoma. Therefore it is very important to make proper diagnosis of BAC with solitary nodular pattern, since this pattern of BAC is usually curable with a surgical resection. Methods : We reviewed the clinical and radiologic features of patients with pathologically-proven BAC with solitary nodular pattern from January 1995 to September 1996 at Samsung Medical Center. Results : Total 11 patients were identified. 6 were men and 5 were women. Age ranged from 37 to 69. Median age was 60. Most patients with BAC with solitary nodular pattern were asymptomatic and were detected by incidental radiologic abnormality. The chest radiograph showed poorly defined opacity or nodule and computed tomography showed consolidation, ground glass appearance, internal bubble-like lucencies, air bronchogram, open bronchus sign, spiculated margin or pleural tag in most patients. The initial diagnosis on chest X-ray were pulmonary tuberculosis in 4 patients, benign nodule in 2 patients and malignant nodule in 5 patients. The FDG-positron emission tomogram was performed in eight patients. The FDG-PET revealed suggestive findings of malignancy in only 3 patients. The pathologic diagnosis was obtained by transbronchial lung biopsy in 1 patient, by CT guided percutaneous needle aspiration in 2 patients, and by lung biopsy via video-assited thoracocopy in 8 patients. Lobectomy was performed in all patients and postoperative pathologic staging were $T_1N_0N_0$ in 8 patients and $T_2N_0M_0$ in 3 patients. Conclusion : Patients of BAC presenting with solitary nodular pattern were most often asymptomatic and incidentally detected by radiologic abnormality. The chest X-ray showed poorly defined nodule or opacity and these findings were often regarded as benign lesion. If poorly nodule or opacity does not disappear on follow up chest X-ray, computed tomography should be performed. If consolidation, ground glass appearance, open bronchus sign, air bronchogram, internal bubble like lucency, pleural tag or spiculated margin are found on computed tomography, further diagnostic procedures, including open thoracotomy, should be performed to exclude the possiblity of BAC with solitary nodular pattern.

• Tuberculosis and Respiratory Diseases
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• v.47 no.4
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• pp.442-450
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• 1999

Background : Isoniazid(INH) and rifampicin(RFP) are the most effective anti-tuberculosis drugs which make the short-course chemotherapy possible. Although prescribed dosages of INH and RFP in Korea are different from those recommended by American Thoracic Society, there has been few study about pharmacokinetic profiles of INH and RFP in Korean patients who receive INH, RFP, ethambutol(EMB) and pyrazinamide(PZA) simultaneously. Methods : Among the patients with active tuberculosis from Dec. 1997 to July 1998, we selected 17 patients. After an overnight fast, patients were given INH 300mg, RFP 450mg, EMB 800mg and PZA 1500mg daily. Blood samples for the measurement of plasma INH(n=15) and RFP(n=17) level were drawn each at 0, 0.5, 1, 1.5, 2, 4, 6, 8 and 12hrs, and urine was also collected. INH and RFP level in the plasma and the urine were measured by high-performance liquid chromatography(HPLC). Pharmacokinetic parameters such as peak serum concentration(Cmax), time to reach to peak serum concentration(Tmax), half-life, elimination rate constant(Ke), total body clearance(CLtot), nonrenal clearance(CLnr), and renal clearance(CLr) were calculated. Results : 1) Pharmacokinetic parameters of INH were as follows: Cmax; $7.63{\pm}3.20{\mu}g/ml$, Tmax; $0.73{\pm}0.22hr$, half-life; $2.12{\pm}0.84hrs$, Ke; $0.83{\pm}0.15hrs^{-1}$, CLtot; $17.54{\pm}8.89L/hr$, CLnr; $14.74{\pm}8.35L/hr$, CLr; $2.79{\pm}1.31L/hr$. 2) Pharmacokinetic parameters of RFP were as follows: Cmax; $8.93{\pm}3.98{\mu}g/ml$, Tmax; $1.76{\pm}1.13hrs$, half-life; $2.27{\pm}0.54hrs$, Ke; $0.32{\pm}0.08hrs^{-1}$, CLtot; $14.63{\pm}6.60L/hr$, CLr; $1.04{\pm}0.55L/hr$, CLnr; $13.59{\pm}6.21L/hr$. 3) While the correlation between body weight and Cmax of INH was not statistically significant (r=-0.514, p value>0.05), Cmax of RFP was significantly affected by body weight of the patients(r=-0.662, p value<0.01). Conclusion : In Korean patients with tuberculosis, 300mg of INH will be sufficient to reach the ideal peak blood level even in the patients over 50kg of body weight However, 450mg of RFP will not be the adequate dose in the patients who weigh over 50~60kg.

• Tuberculosis and Respiratory Diseases
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• v.45 no.4
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• pp.795-804
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• 1998

Background: Chronic eosinophilic pneumonia(CEP) is interstitial lung disease characterized by multiple infiltration on radiographic study, accumulation of eosinophils in the alveolar space and interstitium of the lung, chronic persistent symptoms and possible relapse. Acute eosinophilic pneumonia(AEP) is a recently described illness, characterized by rapid clinical course, acute respiratory insufficiency and no relapse. Method : To better characterize acute and chronic eosinophilic pneumonia, we studied the clinical and laboratory features of 16 patients(AEP : 7 patients, CEP : 9 patients), which were clinico-pathohistologically diagnosed and not to be associated with organic disorders producing peripheral blood eosinophilia. Results: The mean age was higher for patients with CEP than for patients with AEP ($55.4{\pm}15.1$ vs. $24.6{\pm}7.9$ years, p<0.05). High fever(above $38^{\circ}C$) was presented in all patients of AEP and in one patient(11%) of CEP. All patients of AEP and eight patients (89%) of CEP showed bilateral pulmonary infiltrates, and 6 patients(86%) of AEP and 2 patients(22%) of CEP showed pleural effusion in chest radiograph. The mean white blood cell count of AEP and CEP were $17,186/mm^3$ and $12,867/mm^3$, respectively. The mean peripheral blood eosinophil count of AEP and CEP were $939/mm^3$ and $2,104/mm^3$, respectively. The mean eosinophil fraction of BAL fluid of AEP and CEP were 32.4% (range: 18~47%) and 35.8% (range: 15.3~88.2%), respectively. The mean $PaO_2$ was lower for patients with AEP than for patients with CEP ($44.1{\pm}15.5$ vs. $62.7{\pm}6.9$mmHg, p<0.05). All patients of AEP and CEP were initially treated with antibiotics. All patients of CEP and one patients of AEP were finally required systemic steroid therapy. 6 patients of AEP were improved without steroid therapy. Relapse was observed in 3 patients(33%) of CEP. Conclusion : Compair with of chronic eosinophilic pneumonia, acute eosinophilic pneumonia was characterized by relatively young age, acute onset, high fever, severe hypoxemia, diffuse pulmonary infiltrates with pleural effusion, steroid therapy is effective but spontaneous improvement with conservative therapy was frequent.

• Tuberculosis and Respiratory Diseases
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• v.45 no.6
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• pp.1199-1213
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• 1998

Background : The number of immunocompromised hosts has been increasing steadily and a new pulmonary infiltrate in these patients is a potentially lethal condition which needs rapid diagnosis and treatment. In this study we sought to examine the clinical manifestations, radiologic findings, and therapeutic outcomes of pulmonary mycoses presenting as a new pulmonary infiltrate in immunocompromised hosts. Method : All cases presenting as a new pulmonary infiltrate in immunocompromised hosts and confirmed to be pulmonary mycoses by pathologic examination or by positive culture from a sterile site between October of 1996 and April of 1998 were included in the study and their chart and radiologic findings were retrospectively reviewed. Results : In all, 14 cases of pulmonary mycoses from 13 patients(male : female ratio = 8 : 5, median age 47 yr) were found. Twelve cases were diagnosed as aspergillosis while two were diagnosed as mucormycosis. Major risk factors for fungal infections were chemotherapy for hematologic malignancy(10 cases) and organ transplant recipients(4 cases). Three cases were receiving empirical amphotericin B at the time of appearance of new lung infiltrates. Cases in the hematologic malignancy group had more prominent symptoms : fever(9/10), cough(6/10), sputum(5/10), dyspnea(4/10), chest pain(5/10). Patients in the organ transplant group had minimal symptoms(p<0.05). On simple chest films, all of the cases presented as single or multiple nodules(6/14) or consolidations(8/14). High resolution computed tomograph showed peri-lesional ground glass opacities(14/14), pleural effusions(5/14), and cavitary changes(7/14). Definitive diagnostic methods were as follows : 10 cases underwent minithoracotomy, 2 underwent video-assisted thoracoscopic surgery, 1 underwent percutaneous needle aspiration and 1 case was diagnosed by culture of abscess fluid. All cases received treatment with amphotericin B with 1 case each being treated with liposomal amphotericin B and itraconazole due to renal toxicity. Lung lesion improved in 12 of 14 patient but 4 patients died before completing therapy. Conclusion : When a new lung infiltrate develops presenting either as a nodule or consolidation in a neutropenic patient with hematologic malignancy or in a transplant recipient, you should always consider pulmonary mycoses as one of the differential diagnosis. By performing aggressive work up and early treatment, we may improve prognosis of these patients.

• Tuberculosis and Respiratory Diseases
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• v.45 no.1
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• pp.57-67
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• 1998

Purpose : This study was undertaken to determine the preoperative predictors of mortality and morbidity after lung cancer resection. Method: During the period from October 1, 1995 to August 31, 1996, a prospective study was conducted in 92 lung resection candidates diagnosed as lung cancer. For preoperative predictors of nonpulmonary factors, we considered age, sex, weight loss, hematocrit, serum albumin, EKG and concomitant illness, and for those of pulmonary factors, smoking history, presence of pneumonia, dyspnea scale(1 to 4), arterial blood gas analysis with room air breathing, routine pulmonary function test. And predicted postoperative(ppo) pulmonary factors such as PPO-$FEV_1$, ppo-diffusing capacity(DLco), predicted postoperative product(PPP) of ppo-$FEV_1%{\times}ppo$-DLco% and ppo-maximal $O_2$ uptake($VO_2$max) were also considered. Results: There were 78 men and 14 women with a median age of 62 years(range 42 to 82) and a mean $FEV_1$ of $2.37\pm0.06L$. Twenty nine patients had a decreased $FEV_1$ less than 2.0L. Pneumonectomy was performed in 26 patients, bilobectomy in 12, lobectomy in 54. Pulmonary complications developed in 10 patients, cardiac complications in 9, other complications(empyema, air leak, bleeding) in 11, and 16 patients were managed in intensive care unit for more than 48hours. Three patients died within 30 days after operation. The ppo-$VO_2$max was less than 10ml/kg/min in these three patients, but its statistical significance could not be determined due to small number of patients. In multivariate analysis, the predictor related to postoperative death was weight loss(p<0.05), and as for pulmonary complications, weight loss, dyspnea scale, ppo-DLco and extent of resection(p<0.05). Conclusions: Based on this study, preoperative nonpulmonary factors such as weight loss and dyspnea scale are more important than the pulmonary factors in the prediction of postoperative mortality and/or morbodity in lung resection candidates, but exercise pulmonary fuction test may be useful Our study suggests that ppo-$VO_2$max value less than 10ml/kg/min is associated with death after lung cancer resection but further studies are needed to validate this result.

• Tuberculosis and Respiratory Diseases
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• v.49 no.6
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• pp.740-751
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• 2000

Background : Moxifloxacin is a newly developed drug which is more potent and safe compared to previous fluoroquinolones. This drug effectively eradicates organisms such as beta-lactamase-producing or other resistant bacteria. Moxifloxacin is known to be effective in treating respiratory infections such as Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Chlamydia pneumoniaeme, Legionella spp. and Mycoplasma pneumoniae. Methods : In a multicenter, randomized, open, comparative study, the efficacy and safety of oral moxifloxacin taken 400 mg once a day and clarithromycin taken 500 mg twice daily for 7 days were compared for the treatment of Korean patients with acute exacerbations of chronic bronchitis. Results : A total of 170 patients were enrolled, and they were divided into two groups: 87 in the moxifloxacin group and 83 in the clarithromycin group. Of those enrolled, 76 (35 for bacteriologic efficacy) in the moxifloxacin group and 77 (31 for bacteriologic efficacy) in the clarithromycin group were included in the efficacy analysis. All were included in the safety analysis. Clinical success was noted in 70 (92.1%) of 76 moxifloxacin-treated patients and 71 (92.2%) of 77 clarithromycin-treated patients. Bacteriologic success rate seemed to be higher in moxifloxacin group (73.5%) than in clarithromycin group (54.8%), but statistically insignificant (p=0.098). Drug susceptibility among organisms initially isolated was higher in moxifloxacin group on Streptococcus pneumoniae, Pseudomonas aeruginosa, Klebsiella pneumoniae (p<0.001). Adverse events were reported by 12.8% of 86 patients receiving moxifloxacin and 21.7% of 83 patients receiving clarithromycin. Headache (4.7% vs 4.8%, moxifloxacin group vs clarithromycin group, respectively) and indigestion (2.3% vs 6.0%, moxifloxacin group vs clarithromycin group, respectively) were the most frequent side effects in the two groups. Conclusion : This study demonstrated that for the treatment of acute exacerbations of chronic bronchitis a 7-day course of moxifloxacin 400 mg od was clinically equivalent and microbiologically superior to clarithromycin 500 mg bid.

• Tuberculosis and Respiratory Diseases
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• v.48 no.1
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• pp.14-23
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• 2000

Background: The evaluation of candidates for successful lung resection is important. Our study was conducted to determine the preoperative predictors of postoperative mortality and morbidity in lung cancer patients with impaired lung function. Method; Between October 1, 1995 and August 31, 1997, 36 lung resection candidates for lung cancer with $FEV_1$ of less than 2L or 60% of predicted value were included prospectively. Age, sex, weight loss, hematocrit, serum albumin, EKG and concomitant illness were considered as systemic potential predictors for successful lung resection. Smoking history, presence of pneumonia, dyspnea scale(l to 4), arterial blood gas analysis with room air breathing, routine pulmonary function test were also included for the analysis. In addition, predicted postoperative(ppo) pulmonary factors such as ppo-$FEV_1$ ppo-diffusing capacity(DLco), predicted postoperative product(PPP) of ppo-$FEV_1%{\times}$ppo-DLco% and ppo-maximal $O_2$ uptake($VO_2$max) were also measured. Results: There were 31 men and 5 women with the median age of 65 years(range, 44 to 82) and a mean $FEV_1$ of $1.78{\pm}0.06L$. Pneumonectomy was performed in 14 patients, bilobectomy in 8, lobectomy in 14. Pulmonary complications developed in 10 patients; cardiac complications in 3, other complications(empyema, air leak, bleeding) in 4. Twelve patients were managed in the intensive care unit for more than 48 hours. Two patients died within 30 days after operation. The ppo-$VO_2$max was less than 10 ml/kg/min in these two patients. MVV was the only predictor for the pulmonary complications. However, there was no predictor for the post operative death in this study. Conclusions: Based on the results, MVV was the useful predictor for postoperative pulmonary complications in lung cancer resection candidates with impaired lung function In addition, ppo-$VO_2$max value less than 10 ml/kg/min was associated with postoperative death, so exercise pulmonary function test could be useful as preoperative test. But further studies are needed to validate this result.

• Tuberculosis and Respiratory Diseases
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• v.52 no.1
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• pp.14-23
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• 2002

Background: The opitmal ventilator setting during partial liquid ventilation(PLV) is controversial. This study investigated the effects of various gas exchange parameters during PLV in normal rabbit lungs in order to aid in the development of an optimal ventilator setting during PLV. Methods: Seven New-Zealand white rabbits were ventilated in pressure-controlled mode with the following settings; tidal volume($V_T$) 8 mL/kg, positive end-expiratory pressure(PEEP) 4 $cmH_2O$, inspiratory-to-expiratory ratio(I:E ratio) 1:2, fraction of inspired oxygen($F_TO_2$) 1.0. The respiration rate(RR) was adjusted to keep $PaCO_2$ between 35~45 mmHg. The ventilator settings were changed every 30 min in the following sequence : (1) Baseline, as the basal ventilator setting, (2) Inverse ratio, I:E ratio 2:1, (3) high PEEP, adjust PEEP to achieve the same mean inspiratory pressure (MIP) as in the inverse ratio, (4) High $V_T$, $V_T$ 15 mL/kg, (5) high RR, the same minute ventilation (MV) as in the High $V_T$. Subsequently, the same protocol was repeated after instilling 18 mL/kg of perfluorodecalin for PLV. The parameters of gas exchange, lung mechanics, and hemodynamics were examined. Results: (1) The gas ventilation(GV) group showed no significant changes in the $PaO_2$ at all phases. The $PaCO_2$ was lower and the pH was higher at the high $V_T$ and high RR phases(p<0.05). No significant changes in the lung mechanics and hemodynamics parameters were observed. (2) The baseline $PaO_2$ for the PLV was $312{\pm}$ mmHg. This was significantly lower when decreased compared to the baseline $PaO_2$ for GV which was $504{\pm}81$ mmHg(p=0.001). During PLV, the $PaO_2$, was significantly higher at the high PEEP($452{\pm}38$ mmHg) and high $V_T$ ($461{\pm}53$ mmHg) phases compared with the baseline phase. However, it did not change significantly during the inverse I:E ratio or the high RR phases. (3) The $PaCO_2$ was significantly lower at high $V_T$ and RR phases for both the GV and PLV. During the PLV, $PaCO_2$ were significantly higher compared to the GV (p<0.05). (4) There were no important or significant changes in of baseline and high RR phases lung mechanics and hemodynamics parameters during the PLV. Conclusion: During PLV in the normal lung, adequate $V_T$ and PEEP are important for optimal oxygenation.

• The Korean Journal of Nuclear Medicine
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• v.38 no.6
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• pp.516-521
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• 2004

Background: Radioactive iodine (RAI) therapy and whole-body scanning are the fundamentals of treatment and follow-up of patients with differentiated thyroid cancer. It is generally accepted that a Thyroid-Stimulating Hormone (TSH) level of at least 30 ${\mu}U/ml$ is a prerequisite for the effective use of RAI, and that it requires 4-6 weeks of off-thyroxine to attain these levels. Because thyroxine withdrawal and the consequent hypothyroidism are often poorly tolerated, and occasionally might be hazardous, it is important to be certain that these assumptions are correct. We have measured serial changes in serum TSH after total thyroidectomy or withdrawl of thyroxine in patients with thyroid cancer. Subjects and Methods: Serum TSH levels were measured weekly after thyroidectomy in 10 patients (group A) and after the discontinuation of thyroxine in 12 patients (group B). Symptoms and signs of hypothyroidism were also evaluated weekly by modified Billewicz diagnostic index. Results: By the second week, 78% of group A patients and 17% of group B patients had serum TSH levels ${\geq}30{\mu}U/ml$. By the third week, 89% of group A patients and 90% of group B patients had serum TSH levels ${\geq}30{\mu}U/ml$. By the fourth week, all patients in two groups achieved target TSH levels and there were no overt hypothyroidism. Conclusion: in all patients, serum TSH elevated to the target concentration (${\geq}30{\mu}U/ml$) within 4 weeks without significant manifestation of hypothyroidism. The schedule of RAI administration could be adjusted to fit the needs and circumstances of individual patients with a shorter preparation period than the conventional.

• Journal of Intelligence and Information Systems
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• v.19 no.2
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• pp.101-123
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• 2013

Recently due to the advancements of science and information technology, the socio-economic business areas are changing from the industrial economy to a knowledge economy. Furthermore, companies need to do creation of new value through continuous innovation, development of core competencies and technologies, and technological convergence. Therefore, the identification of major trends in technology research and the interdisciplinary knowledge-based prediction of integrated technologies and promising techniques are required for firms to gain and sustain competitive advantage and future growth engines. The aim of this paper is to understand the recent research trend in management of technology (MOT) and to foresee promising technologies with deep knowledge for both technology and business. Furthermore, this study intends to give a clear way to find new technical value for constant innovation and to capture core technology and technology convergence. Bibliometrics is a metrical analysis to understand literature's characteristics. Traditional bibliometrics has its limitation not to understand relationship between trend in technology management and technology itself, since it focuses on quantitative indices such as quotation frequency. To overcome this issue, the network focused bibliometrics has been used instead of traditional one. The network focused bibliometrics mainly uses "Co-citation" and "Co-word" analysis. In this study, a keywords network analysis, one of social network analysis, is performed to analyze recent research trend in MOT. For the analysis, we collected keywords from research papers published in international journals related MOT between 2002 and 2011, constructed a keyword network, and then conducted the keywords network analysis. Over the past 40 years, the studies in social network have attempted to understand the social interactions through the network structure represented by connection patterns. In other words, social network analysis has been used to explain the structures and behaviors of various social formations such as teams, organizations, and industries. In general, the social network analysis uses data as a form of matrix. In our context, the matrix depicts the relations between rows as papers and columns as keywords, where the relations are represented as binary. Even though there are no direct relations between papers who have been published, the relations between papers can be derived artificially as in the paper-keyword matrix, in which each cell has 1 for including or 0 for not including. For example, a keywords network can be configured in a way to connect the papers which have included one or more same keywords. After constructing a keywords network, we analyzed frequency of keywords, structural characteristics of keywords network, preferential attachment and growth of new keywords, component, and centrality. The results of this study are as follows. First, a paper has 4.574 keywords on the average. 90% of keywords were used three or less times for past 10 years and about 75% of keywords appeared only one time. Second, the keyword network in MOT is a small world network and a scale free network in which a small number of keywords have a tendency to become a monopoly. Third, the gap between the rich (with more edges) and the poor (with fewer edges) in the network is getting bigger as time goes on. Fourth, most of newly entering keywords become poor nodes within about 2~3 years. Finally, keywords with high degree centrality, betweenness centrality, and closeness centrality are "Innovation," "R&D," "Patent," "Forecast," "Technology transfer," "Technology," and "SME". The results of analysis will help researchers identify major trends in MOT research and then seek a new research topic. We hope that the result of the analysis will help researchers of MOT identify major trends in technology research, and utilize as useful reference information when they seek consilience with other fields of study and select a new research topic.