• Management & Information Systems Review
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• v.39 no.2
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• pp.39-60
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• 2020

Block chain technology is one of the core elements for realizing the 4^th industrial revolution, and many efforts have been made by government and companies to provide services based on block chain technology. In this study we analyzed the benefits of block chain technology for EVMS and designed EVMS block chain platform with increased data security and work efficiency for project management data, which are important assets in monitoring progress, foreseeing future events, and managing post-completion. We did the case studies on the benefits of block chain technology and then conducted the survey study on security, reliability, and efficiency of block chain technology, targeting 18 block chain experts and project developers. And then, we interviewed EVMS system operator on the compatibility between block chain technology and EVM Systems. The result of the case studies showed that block chain technology can be applied to financial, logistic, medical, and public services to simplify the insurance claim process and to improve reliability by distributing transaction data storage and applying security·encryption features. Also, our research on the characteristics and necessity of block chain technology in EVMS revealed the improvability of security, reliability, and efficiency of management and distribution of EVMS data. Finally, we designed a network model, a block structure, and a consensus algorithm model and combined them to construct a conceptual block chain model for EVM system. This study has the following contribution. First, we reviewed that the block chain technology is suitable for application in the defense sector and proposed a conceptual model. Second, the effect that can be obtained by applying block chain technology to EVMS was derived, and the possibility of improving the existing business process was derived.

• Investigative Magnetic Resonance Imaging
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• v.13 no.2
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• pp.152-160
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• 2009

Purpose : To intra-individually compare diagnostic accuracy of high-resolution contrast-enhanced magnetic resonance angiography (CE-MRA) with computed tomography angiography (CTA) and digital subtraction angiography (DSA) for the assessment of supraaortic steno-occlusive disease. Materials and Methods : Twenty-eight patients (20 men, 8 women, 53-79 years of age) underwent supraaortic CE-MRA, CTA and DSA. CE-MRA was performed on two 1.5T MR scanners (voxel dimension: $0.66{\times}0.66{\times}1.1$ or $1.2\;mm^3$), and CTA on 64-slice CT scanners (voxel dimension: $0.42{\times}0.42{\times}0.63\;mm^3$). All the three examinations were completed within 40 days (median 19 days; range 1-40 days). Retrospective evaluation and measurement of diameter of 6 extracranial and 9 intracranial arterial segments was done by 2 experienced radiologists. Results: A total of 420 arterial segments were examined by CE-MRA, CTA and DSA. On DSA, 34 stenoocclusive lesions were noted at extracranial (n= 19) and intracranial (n = 15) vessels. For extracranial stenosis greater than 70%, sensitivity, specificity, positive predictive value (PPV) and negative predictive values (NPV) were 94.7%, 98.7%, 90.0% and 99.3% on CE-MRA, and 94.7%, 99.3%, 94.7% and 99.3% on CTA. For intracranial stenosis greater than 50%, sensitivity; specificity, PPV and NPV were 93.3%, 98.3%, 77.8%and 99.6% on CE-MRA, and 86.7%, 97.9%, 72.2% and 99.1 % on CTA, with DSA as the standard of reference. Conclusion : Supraaortic CE-MRA is as reliable as CTA in depicting the arterial stenosis, and is effective in screening of significant stenosis of both extracranial and intracranial arterial stenosis.

• Journal of Chest Surgery
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• v.31 no.10
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• pp.988-994
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• 1998

Background: Chest wall tumors can classified into soft tissue tumors and bone tissue tumors and can be subclassified into benign and malignant tumors. Materials and methods: We report an analysis of 68 patients with primary chest wall tumors treated at the department of thoracic and cardiovascular surgery at Hanyang University Hospital from January, 1973 to September 1997. Results: Among a total of 68 patients 33(48.5%) were males and 35(51.5%) were females. The ages of the patients ranged from 10 to 79 years with a mean age of 39.3 years. According to the age distribution, 23 patients (33.8%) were from the 4th decade, 12 patients(17.6%) were from the 6th decade, and 10 patients(14.7%) were from the 5th decade. Among the primary chest wall tumors, 53 cases were benign and 15 cases were malignant. Among the benign tumors, 17 cases(32.1%) were in the 4th decade and among the malignant tumors, 6 cases(40%) were in the 4th decade. In both malignant and benign tumors the most common ages were in the 4th decade. The most common tumors were fibrous dysplasia and chondroma, each with a total of 14 cases(26.4%). Osteochondroma and lipoma each had 8 cases(15.1%). Among malignant tumors, osteosarcoma was most common with 8 cases (53.3%). According to location, 49 cases occured in both bone and cartilage tissue, 19 cases occurred in cartilage. Among the presenting symptoms, palpable mass was present in all cases. Fifty-one patients complained of tenderness and among cases with involvement of the lung, 3 patients had complained of respiratory distress. Among the malignant tumors 6 cases underwent a radical operation and 4 cases of benign tumors underwent a radical operation. Postoperativly, there was one case with recurrence from a desmoid tumor. There were no deaths postoperativly and no deaths due to complications(and their postoperative courses were uneventful). Conclusions: Most patients with primary chest wall tumors initially present with mass at admission. Resection is sufficient treatment for benign tumors but in malignant tumors wide resection of the chest wall is needed and mchest wall reconstruction.

• Journal of Korean Ophthalmic Optics Society
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• v.21 no.2
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• pp.99-108
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• 2016

Purpose: The present study was aimed to compare the tear volume and distribution by corneal eccentricity when fitted with spherical and aspherical RGP lenses. Methods: Spherical and aspherical RGP lenses were fitted in best alignment on a total of 77 subjects (136 eyes) in their twenties and thirties without any ocular disease or ocular surgery experience. The tear volume was analyzed by estimating the concentration of tear stained with fluorescein in the center of RGP lens as well as at the mid-peripheral and peripheral areas, and the difference of tear distributions was analyzed according to corneal eccentricity. Results: Tear distribution from the center to the peripheral area was not significantly different when spherical RGP lenses were fitted on the corneal eccentricities of e < 0.38 and $0.68{\leq}e$, indicating the relatively even tear distribution compared with other corneal eccentricity. In the case of aspherical RGP lenses, the difference of tear distribution between the central and peripheral areas was smaller than spherical RGP lenses. The significant difference of tear distribution according to RGP lens design was observed in the corneal eccentricity of 0.48 < e < 0.68. In other words, more even tear distribution was shown when aspherical RGP lenses were fitted on the cornea with eccentricity of $0.48{\leq}e<0.68$ and spherical RGP lenses were fitted on the cornea with eccentricity $0.68{\leq}e$. Furthermore, tear volume in the mid-peripheral area increased with higher corneal eccentricity. Conclusions: The results suggest that the appropriate selection of RGP lens design according to corneal eccentricity is necessary since tear volume and distribution by the regions of spherical and aspherical lenses are affected by corneal eccentricity.

• Journal of Chest Surgery
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• v.32 no.4
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• pp.373-378
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• 1999

Background: Minimally invasive technique for various cardiac surgeries has become widely accepted since it has been proven to have distinct advantages for the patients. We describe here the results of our experiences of minimal incision in cardiac surgery. Material and Method: From February 1997 to November 1998, we successfully performed 31 cases of minimally invasive cardiac surgery. Male and female ratio was 17:14, and the patients age ranged from 1 to 75 years. A left parasternal incision was used in 9 patients with single vessel coronary heart disease. A direct coronary bypass grafting was done under the condition of the beating heart without cardiopulmonary bypass support(MIDCAB). Among these, one was a case of a reoperation 1 week after the first operation due to a kinked mammary artery graft. A right parasternal incision was used in one case of a redo mitral valve replacement. Mini-sternotomy was used in the remaining 21 patients. The procedures were mitral valve replacement and tricuspid annuloplasty in 6 patients, mitral valve replacement 5, double valve replacement 2, aortic valve replacement 1, removal of left atrial myxoma 1, closure of atrial septal defect 2, repair of ventricular septal defect 2, and primary closure of r ght ventricular stab wound 1. The initial 5 cases underwent a T-shaped mini-sternotomy, however, we adopted an arrow-shaped ministernotomy in the remaining cases because it provided better exposure of the aortic root and stability of the sternum after a sternal wiring. Result: The operation time, the cardiopulmonary bypass time, the aorta cross-clamping time, the mechanical ventilation time, the amount of chest tube drainage until POD#1, the chest tube indwelling time, and the duration of intensive care unit staying were in an acceptable range. There were two surgical mortalities. One was due to a rupture of the aorta cannulation site after double valve replacement on POD#1 in the mini-sternotomy case, and the other was due to a sudden ventricular arrhythmia after MIDCAB on POD#2 in the parasternal incision case. Postoperative complications were observed in 2 cases in which a cerebral embolism developed on POD#2 after a mini-sternotomy in mitral valve replacement and wound hematoma developed after a right parasternal incision in a single coronary bypass grafting. Neither mortality nor complication was directly related to the incision technique itself. Conclusion: Minimally invasive surgery using parasternal or mini-sternotomy incision can be used in cardiac surgeries since it is as safe as the standard full sternotomy incisions.

• The Journal of the Korean bone and joint tumor society
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• v.11 no.1
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• pp.71-81
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• 2005

Purpose: Due to local recurrence of tumor, metal failure usually develops in patients who underwent internal fixation or hip joint arthroplasty after curettage in the case of metastatic tumor of proximal femur. The aim of this study is to find out the appropriateness of reconstruction using recycling autograft after wide excision in the case of metastatic bone tumor by performing recycling autograft and hip joint arthroplasty after wide excision, and through presence or absence of local recurrence, functions of lower limbs and occurrence of complications. Materials and Methods: Five patients, in 6 cases, who had undergone reconstruction using recycling autograft prosthetic composite after wide excision in the metastatic tumor from May 2000 to May 2003 were included in this study. The average age of the patients was 60.8 years of age with male to female ratio of 3:2. Average duration of lives following surgery was 23.3 month (7-57 months). Primary lesion included 2 cases of lung cancer, and 1 each of stomach cancer, renal cancer and multiple myeloma. After wide excision, the hip joint was reconstructed with recycling autograft prosthetic composite ; 4 cases of extracorporeal irradiation and 2 cases of pasteurization. Musculoskeletal Tumor Society (MSTS) score(1993) for 6-month period after surgery, as well as presence of complication and local recurrence during the rest of their lives, were studied. Results: Average Musculoskeletal Tumor Society (MSTS) score over the 6-month period after surgery was 63.3% and 1 case of dislocation of hip joint, as a complication following surgery, was discovered. Local recurrence during the lives of the patients was not observed. Conclusion: In the case of metastatic tumor of proximal femur, in which the life span following surgery is expected to be more than 6 months, undergoing reconstruction using recycling autograft after wide excision, in comparison to internal fixation or hip joint arthroplasty after curettage, is deemed to have better results in prevention of local recurrence, and preservation of the functions of all limbs during the life span of the patient.

• Journal of Chest Surgery
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• v.34 no.8
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• pp.615-620
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• 2001

The new stage of metastatic lung cancer based upon resectability, disease-free interval, and the number of pulmonary metastases was proposed in 1998 by Ginsberg, et al. We evaluated the validity of the new staging proposal for pulmonary metastases through the analysis of experiences at Severance Hospital. Material and Method: The cases of 111 patients who underwent resection of metastatic lung cancer during the eleven-year period (1990-2000) were reviewed. Of these patients, 103(92.8%) underwent compete surgical resection. The primary tumor was carcinoma in 60 cases, sarcoma in 46, and others in 5. The disease-free interval(DFI) was 0 to 35 months in 79 cases adn more than 36 months in 32 cases. Single metastasis accounted for 53 cases and multiple lesions for 58 cases. Mean follow-up was 49 months. Result: The actuarial survival after complete metastasectomy was 48.2% at 3 years and 32.6% at 5 years; the corresponding values for incomplete resection were 21.9% at 3 years. The 3-year survival rate(3-YSR) for complete resction was 40.5% and 5-year survival rate(5-YSR) was 30.4% for patients with a DFI less than 36 months, the 3-YSR, 75.8% and 5-YSR, 39.0% for those with a DFI equal or more than 36 moths; 45.8% and 30.5% for single lesions, 50.0% and 34.4% for multiple lesions. The 3-YSR and 5-YSR were 58.5% and 43.8% for stage I patients, 54.0% and 37.4% for stage II, 38.2% and 27.9% for stage III and 21.9% for stage IV. Conclusion: The result of the analysis of new stage of pulmonary metastases showed that the survival rate was different according to stage and there was no statistical significance. We need more experiences and long-term follow up to determine the prognostic factor of metastatic lung cancer surgery.

• Journal of Hospice and Palliative Care
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• v.21 no.2
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• pp.51-57
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• 2018

Purpose: End-of-life (EoL) decisions are challenging and multifaceted for patients and physicians. This study was aimed to explore how EoL care is practiced for patients with a do-not-resuscitate (DNR) order. Methods: We retrospectively analyzed medical records of patients who died after agreeing to a DNR order in 2016 at a university hospital. Characteristics including cause of death, intensity of EoL care, and other factors were reviewed and statistically analyzed. Results: Of total 375 patients, 170 patients (45.3%) died with malignancies, and 205 patients (54.6%) with other causes involving the central nervous system (19.2%), pulmonary (14.7%), cardiologic (6.7%) and infectious (6.4%) conditions. Both the cancer and non-cancer patient groups showed a short duration from DNR to death (median 3 days vs 2 days, P=0.629). An intensive care group comprising patients who received one or more intensive treatments such as ventilator (n=205) showed a higher number of non-cancer patients and a shorter duration from DNR to death than a group that withheld treatment before DNR (P<0.05). Conclusion: EoL decisions were made very late by both cancer and non-cancer patients. About half of the patients did not have cancer, and two-thirds of them decided DNR during intensive treatment. To make a good EoL decision, a shared decision making with patients should be done at an earlier stage.

• Journal of Hospice and Palliative Care
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• v.5 no.1
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• pp.24-30
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• 2002

Background : Pain is one of the most feared consequences of cancer. $65{\sim}85%$ of cancer patients experienced severe pain, and sometimes high dose morphine is used to these patients. But many doctors still have 'opioid-phobia' and hesitate to use high dose morphine. We investigated the morphine therapy in terminal cancer patients during the last 1 week to death, and found any differences according to the morphine dosage. Methods : 93 patients admitted to National Health Insurance Corporation Ilsan Hospital, department of family medicine for hospice care between September 2000 and the end of October 2001 and lived more than 1 week entered in the study. We investigated the demographic data, laboratory tests and sufficient dosage of morphine for pain control. According to the calculated dosage by OME(oral morphine equivalent), patients were divided into low dosage group (${\leq}150mg/day$) and high dosage group (>150 mg/day). The chi-squared test were used to evaluate the influence of age, gender, tumor sites, metastasis and adverse effects of morphine. Results : Mean age was $65.0{\pm}13.1year$ in low dosage group and $59.9{\pm}11.6year$ in high dosage group. 32 men (50.0%) and 32 women (50.0%) were included in low dosage group and 15 men (51.7%) and 14 women (48.3%) in high dosage group. Stomach was the most frequent tumor site and lung was the next. Metastasis were found 58 (90.6%) in low dosage group and 28 (96.6%) in high dosage group. In other palliative radiotherapy and adverse effects, there were no differences in both group. Conclusion : During the last 1 week to death in cancer patients, there were no difference according to the morphine dosage. So we don't have to have 'opioid-phobia' in treating the terminal cancer patients.

• Tuberculosis and Respiratory Diseases
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• v.51 no.5
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• pp.426-436
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• 2001

Objective : This study was performed to determine the smoking status and its associated factors in military life among young Korean men to provide data for smoking prevention in military areas as a part of the health promotion program for soldiers. Methods : 1,033 infantrymen serving in 17 military units, which are located in suburbs of K city, were enrolled in this study. A questionnaire on the soldiers smoking status and other various characteristics was obtained from October 2nd to 12th, 2000. Logistic regression analysis was performed on the various variables in order to determine the factors related to smoking. Results : 1) 830(80.3%) out of 1033 subjects had smoked cigarettes and 759 persons(73.4%) were regular smokers. 2) Among the 734 soldiers who started smoking before their military service, 714 soldiers(97.2%) continued to smoke after, while 45 soldiers(15.0%) among the 299 non-smokers started smoking after joining the army. 3) Through the logistic regression analysis. the education level. specialty in the army. smoking amongst the friends they met before military service, smoking amongst soldiers in the army. dating girl friends, drinking, satisfaction with their army lives and the presence of convenient smoking places at the barracks were significant factors related to the prevalence of smoking in soldiers. Conclusion : The factors related with incidence of smoking in the army are the complicated interactions among the individuals personal background, general characteristics of the soldier and the special environment in the barracks. Therefore, to improve national soldiers' health, an active non-smoking campaign and education should be pushed to discourage smoking in the barracks.