• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.1
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• pp.77-83
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• 2019

Major causes of industrial accidents include falls and gas leak. The existing safety helmet and smart device combination products are focused on convenience, so the functions to prevent such accidents are insufficient. We developed a smart helmet focusing on fall accident detection and gas leak detection. We also developed management system to manage workers efficiently. Its core function is to detect dangerous conditions of employees, to communicate with managers and to confirm the situations of workers. The effectiveness of the combustible gas measurement capability was verified through experiments. However, since a significant amount of power consumption is founded due to continuous operation of the board and the sensor, countermeasures such as replacing with a large capacity battery are required.

• Journal of Chest Surgery
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• v.29 no.4
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• pp.403-407
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• 1996

One hundred and twenty three patients underwent 137 thoracostomies for spontaneous pneumothorax in the department of Thoracic and Cardiovascular Surgery, Gyeongsang National University from January 1987 to December 1994. There were 118 men and 6 women and average age was )2.4 years. The two most common surgical Indications were recurrent pneumothorax and continuous air leakage. Other indications were visible bullae on simple X-ray, previous contralateral pneumothorax, incomplete expansion of the lung, and bilateral pneumothoraces. Methods of thoracotomy were subaxillary thoracotomy in 82 cases, lateral minithoracotomy in 12 cases and posterolateral thoracotomy in 43 cases. Operation time was 63.0 $\pm$ 30.8, 98.3 $\pm$ 37.9, 186.9 $\pm$ 87.9 minutes respectively, and postoperative chest tube keeping time was 5.2 $\pm$ 4.1 days in subaxillary thoracotomy, 6.2 $\pm$ 5.0 days in minithoracotomy and 10.0 $\pm$ 5.8 days in posterolateral thoracotomy Bullae were present mostly at the apex in spontaneous and tuberculous pneumothorax comparred to the cases of chronic obstructive or emphysematous lung disease, where there were no redilection of presence of bullae (p< 0.01). Operative procedures were wedge resection, bullae obliteration and lobectomy. Postoperative complications were continuous air leakage, bleeding, brachial plexus injury, empyema, and wound infection, but all the complications were cured by the time of discharge. There was no mortality.

• Journal of Gastric Cancer
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• v.6 no.1
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• pp.52-56
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• 2006

A 69-year old man presented with severe epigastric pain for 1 day. He had early gastric cancer at the antrum and underwent a distal subtotal gastrectomy and Billorth II gastrojejunostomy one month later without any post-operative complications. Radiologic examination revealed a large amount of retroperitoneal free air formation. Because of unremitting pain and unstable vital sign, exploratory laparotomy was followed. During the operation, a perforated duodenal diverticulum at the posterior wall of the 2nd portion of the duodenum was identified. He underwent diverticulectomy and primary closure. He was discharged on the 18th post operative day and has been followed up without any evidence of comlpication for several months.

• Neonatal Medicine
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• v.18 no.1
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• pp.153-157
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• 2011

Pneumopericardium is a rare form of neonatal air leakage. Tension pneumopericardium is much more infrequent, but can cause a cardiovascular deterioration with high mortality up to 80% and neurodevelopmental morbidity in half of the cases. We report two cases of preterm infants who successfully recovered from tension pneumopericardium that developed during mechanical ventilator assistance. The patients displayed a sudden increase in oxygen demand and subsequent cardiovascular deterioration. Immediate needle aspiration of the pneumopericardium performed after checking X-ray images rescued each of patient. Since the clinical symptoms are non-specific, clinicians' suspicion is most important when patients show sudden refractory cardiovascular collapse, especially in ventilator-assisted neonates. This life threatening complication demands instant diagnosis and intervention.

• Journal of the Korean Institute of Gas
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• v.25 no.3
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• pp.27-38
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• 2021

We devised the system to automatically shutdown the boiler and to fundamentally block the harmful gases, including carbon monoxide, into the indoor when the exhaust system swerves: (1) The discharge pressure of the exhaust gas decreases when the exhaust pipe is disconnected. The monitoring system of the exhaust pipe is implemented by measuring the output voltage of APS(Air Pressure Sensor) installed to control the amount of combustion air. (2) The operating software was modified so that when the system recognizes the fault condition of a flue pipe, the boiler control unit displays the fault status on the indoor regulator while shutting down the boiler. In accordance with the ventilation facility standards in the "Rules for Building Equipment Standards" by the Ministry of Land, Infrastructure and Transport, experiments were conducted to ventilate indoor air. When carbon monoxide leaked in worst-case scenario, it was possible to prevent poisoning accidents. However, since 2013, the number of indoor air exchange times has been mitigated from 0.7 to 0.5 times per hour. We observed the concentration exceeding TWA 30 ppm occasionally and thus recommend to reinforce this criterion. In conclusion, if the flue pipe fault detection and the indoor air ventilation system are introduced, carbon monoxide poisoning accidents are expected to decrease significantly. Also when the manufacturing and inspection steps, the correct installation and repair are supplemented with the user's attention in missing flue, it will be served to prevent human casualties from carbon monoxide poisoning.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.10
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• pp.103-112
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• 2006

This paper describes a theoretical analysis and experimental verification on the performances of a vacuum-compatible air bearing, which is designed with a cascaded exhaust scheme to minimize the air leakage in a vacuum environment. The design of the vacuum-compatible air bearing equipped with the differential exhaust system requires great care because several design parameters, such as the number of exhaust stages, diameter of exhaust tube, pumping speed of a vacuum pump, and bearing clearance greatly influence the air leakage and thus degree of vacuum. In this study, a performance analysis method was proposed to estimate the performances of the air bearing, such as load capacity, stiffness, and air leakage. Results indicate that the load capacity and stiffness of the air bearing was improved as its boundary pressure, which was determined by the $1^{st}$ exhaust method, was lowered, and the dominant factors on the chamber's degree of vacuum were the number of exhaust stages, exhaust tube diameter and bearing clearance. A vacuum chamber and air bearing stage using porous pad were fabricated to verify the theoretical analysis. The results demonstrate that chamber pressure up to an order of $10^{-3}$ Pa was achieved with the air bearing stage operating inside the chamber, and this analysis method was valid by comparing predicted values with experimental data, for the mass flow rates from the porous pad, and pressures at each exhaust port and chamber, respectively.

• Journal of Radiation Protection and Research
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• v.30 no.1
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• pp.45-54
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• 2005

A dynamic compartment model was developed to appraise the level of the contamination of agricultural plants by accidentally released tritium from nuclear facility. The model consists of a set of inter-connected compartments representing atmosphere, soil and plant. In the model three categories of plant are considered: leafy vegetables, grain plants and tuber plants, of which each is modeled separately to account for the different transport pathways of tritium. The predictive accuracy of the model was tested through the analysis of the tritium exposure experiments for rice-plants. The predicted TFWT(tissue free water tritium) concentration of the rice ear at harvest was greatly affected by the absolute humidity of air, the ratio of root uptake, and the rate of rainfall, while its OBT(organically bound tritium) concentration the stowing period of the ear, the absolute humidity of air and the content of hydrogen in the organic phase. There was a good agreement between the model prediction and the experimental results lot the OBT concentration of the ear.

• Journal of Chest Surgery
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• v.31 no.4
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• pp.369-373
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• 1998

The bullectomy through the limited transaxillary thoracotomy and video-assisted thoracic surgery(VATS) had been used in operative management of spontaneous pneumothorax from Jan. 1994 to July 1997. The study comprised a retrospective review of 42 cases which were treated by limited thoracotomy, and 61 cases treated by video-assisted thoracoscopic sugery. We retrospectively reviewed annual incidnce of bullectomy. Analysis of video-assised thoracoscopic surgery and open bullectomy including age, sex, operative sites, surgical indications, associated diseases, operative time, posoperatve complications and hospital courses. There was no significant difference for operation time in two groups, 98.3${\pm}$38.4 minutes in thoracotomy and 95.7${\pm}$31.5 minutes in VATS. Prolonged air leakage over 7 days was observed in 8 cases from thoracotomy group, 4 cases from VATS group. 3 cases of recurrent pneumothorax were found from VATS group, but no recurrence was occurred from open bullectomy group. There were significant differences in postoperative hospital stay (8.0${\pm}$3.9 day in thoracotomy vs 5.9${\pm}$2.4day in VATS(P=0.001)), and indwelling period of chest tube after operation( 5.8${\pm}$3.0day in thoracotomy vs 4.0${\pm}$2.0day in VATS(P=0.0006)).

• Journal of Korea Soil Environment Society
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• v.5 no.1
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• pp.13-23
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• 2000

The effects of operating condition of soil vapor extraction system and the characteristics of site on the remediation of oil contaminated soil were investigated. Thorough investigation showed that the site was contaminated with gasoline leaked from underground storage tank and the maximum concentration of BTEX and TPH were 1,081 ppm and 5,548 ppm respectively. The leaked gasoline were diffused to 6m deep and the area and volume of the polluted soil were assumed to 170$m^2$ and 1,000$\textrm{m}^3$respectively. The site were consisted of three different vertitical layers, the top reclaimed sandy soil between the earth surface and 3~4m deep, middle silty sand between 3~4m and 6m deep, and the bottom bedrock below the 6m deep. The air pemeability of soil was measured to 1.058-1.077$\times$10$^{-6}$ $\textrm{mm}^2$ by vacuum pump tests. The groundwater which level was 3~4m deep was observed in some areas of this site. The soil vapor extraction system which had 7.5 HP vacuum pump and 8 extraction wells was constructed in this site and operated at 8 hrs/day for 100 days. The BTEX was removed with above 90% efficiency where no groundwater and silty sand were observed. On the contrary, the efficiency of BTEX and TPH were dramatically decreased where groundwater and silty sand were observed. The flow rate of soil air induced by soil vapor extraction system was reduced in deeper soil.

• Journal of Chest Surgery
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• v.40 no.7 s.276
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• pp.485-491
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• 2007

Background: Thoracoplasty has become a rarity in current clinical practice, although it has been widely employed for well over a century as a procedure for reducing the capacity of the thoracic cavity. Yet we have perform tailoring thoracoplasty following or concomitant with pulmonary resection in 20 patients. The aim of this study is to evaluate the early and late clinical results and also the significance of tailoring thoracoplasty. Material and Method: From March 1995 to June 2005, modified thoracoplasty following or concomitant with pulmonary resection was performed in 20 patients out of a total of 298 pulmonary resections for closing air leaks and for treating persistent pleural space following pulmonary resections, and to tailor the thoracic cavity to accept a diminished lung volume. Of the 20 patients, 14 patients had tailoring thoracoplasty performed concomitant with pulmonary resection, and the remaining 6 patients also had tailoring thoracoplasty performed following pulmonary resection. The subjects ages ranged from 24 to 77 (mean $59.1{\pm}6.4$) and a male preponderance was noted (17 : 3); the number of left and right surgeries was equal. The preoperative primary underlying diseases were lung cancer in 7 patients, pneumothorax with giant bullous change in 6 patients, bronchiectasis in 2 patients, previous pulmonary tuberculosis associated with aspergilloma in 2 patients, empyema with fibrothorax in 2 patients and multiple lung abscesses & destruction due to previous trauma in 1 patient. The operative methods were apicolysis and subperiosteal removal of the 2nd, 3rd and 4th ribs (the costochondral junction to the posterior portions of the ribs) with preservation of the first rib and compression of the anterior chest via cotton bags and elastic bandages. Result: The mean duration of the air leaks after thoracoplasty was $1.6{\pm}0.2$ days (range: $0{\sim}7$ days) and the mean duration of an indwelling chest tube was 7 days (range: $5{\sim}11$ days); the mean duration of hospitalization was $19.2{\pm}2.8$ days (range: $8{\sim}47$ days). The postoperative complications were wound infection (2) and pneumonia (2); reoperation was done due to bleeding (1) in one patient who underwent concomitant thoracoplasty and there was 1 case of wound infection (1) after postresection thoracoplasty. The mortality was 1 patient in the early phase and 4 patients in the late phase. Conclusion: We conclude that tailoring thoracoplasty may be performed to close anticipated persistent pleural spaces and to accommodate the diminished lung volume with acceptable cosmetic results when this procedure is combined with pulmonary resection in selected patients.