• Journal of the Korean Society of Marine Environment & Safety
• /
• v.29 no.7
• /
• pp.964-970
• /
• 2023

As part of the International Maritime Organization ef orts to reduce greenhouse gas emissions, the maritime industry is exploring low-carbon fuels such as liquefied natural gas and methanol, as well as zero-carbon fuels such as hydrogen and ammonia, evaluating them as environmentally friendly alternatives. Particularly, ammonia has substantial operational experience as cargo on transport ships, and ammonia ship engines are expected to be available in the second half of 2024, making it relatively accessible for commercial use. However, overcoming the toxicity challenges associated with using ammonia as a fuel is imperative. Detection is possible at levels as low as 5 ppm through olfactory senses, and exposure to concentrations exceeding 300 ppm for more than 30 min can result in irreparable harm. Using the KORA program provided by the Chemical Safety Agency, an assessment of the potential risks arising from leaks during ammonia bunkering was conducted. A 1-min leak could lead to a 5 ppm impact within a radius of approximately 7.5 km, affecting key areas in Busan, a major city. Furthermore, the potentially lethal concentration of 300 ppm could have severe consequences in densely populated areas and schools near the bunkering site. Therefore, given the absence of regulations related to ammonia bunkering, the potential for widespread toxicity from even minor leaks highlights the requirement for the development of legislation. Establishing an integrated system involving local governments, fire departments, and environmental agencies is crucial for addressing the potential impacts and ensuring the safety of ammonia bunkering operations.

• Information Systems Review
• /
• v.23 no.3
• /
• pp.97-125
• /
• 2021

Blockchain is a core technology to solve personal information leakage and data management issues, which are limitations of existing Genomic Sequencing services. Due to continuous cost reduction and deregulation, the market size of Genomic Sequencing has been increasing, also the potential of services is expected to increase when Blockchain's security and connectivity are combined. We created our research model by combining the Technology Acceptance Model (TAM) and the Innovation Resistance Theory also analyzed the factors affecting the acceptance intention and innovation resistance of the Blockchain Based Genomic Sequencing Information Platform. A survey was conducted on 150 potential users of Blockchain and Genomic Sequencing services. The analysis was conducted by setting the four Blockchain variables: Security, transparency, availability, and diversity). Also, we set the Perceived Usefulness, Perceived risk, and Perceived Complexity for Technology Acceptance and Innovation Resistance variables and analyzed the effect of the characteristics of the Blockchain on acceptance intention and innovation resistance through these variables. Through this analysis, key variables that need to be considered important to reduce resistance and increase acceptance intention could be identified. This study presents innovation factors that should be considered in companies preparing a new Blockchain Based Genomic Sequencing Information Platform.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.34 no.2
• /
• pp.207-216
• /
• 2024

As big data was built due to the 4th Industrial Revolution, personalized services increased rapidly. As a result, the amount of personal information collected from online services has increased, and concerns about users' personal information leakage and privacy infringement have increased. Online service providers provide privacy policies to address concerns about privacy infringement of users, but privacy policies are often misused due to the long and complex problem that it is difficult for users to directly identify risk items. Therefore, there is a need for a method that can automatically check whether the privacy policy is safe. However, the safety verification technique of the conventional blacklist and machine learning-based privacy policy has a problem that is difficult to expand or has low accessibility. In this paper, to solve the problem, we propose a safety verification technique for the privacy policy using the GPT-3.5 API, which is a generative artificial intelligence. Classification work can be performed evenin a new environment, and it shows the possibility that the general public without expertise can easily inspect the privacy policy. In the experiment, how accurately the blacklist-based privacy policy and the GPT-based privacy policy classify safe and unsafe sentences and the time spent on classification was measured. According to the experimental results, the proposed technique showed 10.34% higher accuracy on average than the conventional blacklist-based sentence safety verification technique.

• Journal of Chest Surgery
• /
• v.57 no.1
• /
• pp.62-69
• /
• 2024

Background: Cervical esophageal cancer is a rare malignancy that requires specialized care. While definitive chemoradiation is the standard treatment approach, surgery remains a valuable option for certain patients. This study examined the surgical outcomes of patients with cervical esophageal cancer. Methods: The study involved a retrospective review and analysis of 24 patients with cervical esophageal cancer. These patients underwent surgical resection between September 1994 and December 2018. Results: The mean age of the patients was 61.0±10.2 years, and 22 (91.7%) of them were male. Furthermore, 21 patients (87.5%) had T3 or T4 tumors, and 11 (45.8%) exhibited lymph node metastasis. Gastric pull-up with esophagectomy was performed for 19 patients (79.2%), while 5 (20.8%) underwent free jejunal graft with cervical esophagectomy. The 30-day operative mortality rate was 8.3%. During the follow-up period, complications included leakage at the anastomotic site in 9 cases (37.5%) and graft necrosis of the gastric conduit in 1 case. Progression to oral feeding was achieved in 20 patients (83.3%). Fifteen patients (62.5%) displayed tumor recurrence. The median time from surgery to recurrence was 10.5 months, and the 1-year recurrence rate was 73.3%. The 1-year and 3-year survival rates were 75% and 33.3%, respectively, with a median survival period of 17 months. Conclusion: Patients with cervical esophageal cancer who underwent surgical resection faced unfavorable outcomes and relatively poor survival. The selection of cases and decision to proceed with surgery should be made cautiously, considering the risk of severe complications.

• Journal of Navigation and Port Research
• /
• v.47 no.6
• /
• pp.437-447
• /
• 2023

By actively adopting technologies from the Fourth Industrial Revolution, the port industry is trending toward new types of ports, such as automated and smart ports. However, behind the development of these ports, there is an increasing risk of cyber security incidents and threats within ports and container terminals, including information leakage through cargo handling equipment and ransomware attacks leading to disruptions in terminal operations. Despite the necessity of research to enhance cyber security within ports, there is a lack of such studies in the domestic context. This study focuses on Busan Port, a representative port in South Korea that actively incorporates technology from the Fourth Industrial Revolution, in order to discover variables for improving cyber security in container terminals. The research results categorized factors for enhancing cyber security in Busan Port's container terminals into network construction and policy support, standardization of education and personnel training, and legal and regulatory factors. Subsequently, multiple regression analysis was conducted based on these factors, leading to the identification of detailed factors for securing and enhancing safety, reliability, performance, and satisfaction in Busan Port's container terminals. The significance of this study lies in providing direction for enhancing cyber security in Busan Port's container terminals and addressing the increasing incidents of cyber security attacks within ports and container terminals.

• Korean Chemical Engineering Research
• /
• v.62 no.1
• /
• pp.27-35
• /
• 2024

Fuel gases such as methane and propane are used in explosion hazardous area of domestic plants and can form non-uniform mixtures with the influence of process conditions due to leakage. The fire-explosion risk assessment using literature data measured under uniform mixtures, damage prediction can be obtained the different results from actual explosion accidents by gas leaks. An explosion characteristics such as explosion pressure and flame velocity of non-uniform gas mixtures with concentration change similar to that of facility leak were examined. The experiments were conducted in a closed 0.82 m long stainless steel duct with observation recorded by color high speed camera and piezo pressure sensor. Also we proposed the quantification method of non-uniform mixtures from a regression analysis model on the change of concentration difference with time in explosion duct. For the non-uniform condition of this study, the area of flame surface enlarged with increasing the concentration non-uniform in the flame propagation of methane and was similar to the wrinkled flame structure existing in a turbulent flame. The time to peak pressure of methane decreased as the non-uniform increased and the explosion pressure increased with increasing the non-uniform. The ranges of K_G (Deflagration index) of methane with the concentration non-uniform were 1.30 to 1.58 [MPa·m/s] and the increase rate of K_G was 17.7% in methane with changing from uniform to non-uniform.

• Information Systems Review
• /
• v.19 no.3
• /
• pp.155-177
• /
• 2017

The purpose of this study is to investigate those factors that are influenced when a user recognizes his/her private information value as an economic asset. The relationship among these factors will also be discussed. This research targets Internet users, and the value of their private information will be converted into economic figures. How economic value changes in relation with individual attributes, dealer's traits, and circumstantial properties will also be studied. The changes in the factors of private information value under different situations will be analyzed from an economic perspective. By using the cost-benefit analysis framework, this work hypothesizes that the user's private information value can be influenced by individual attributes and situational properties. in the business aspect, this study can help users recognize the true value of their personal information and minimize the cost resulting from private information security incidents. This work also highlights the necessity of estimating the scale of investments for protecting private information. Overall, this research will proceed under the hypothesis that the users' recognition of their private information value is influenced by the attributes of the individual, dealers, or situations.

• Journal of the Society of Disaster Information
• /
• v.20 no.1
• /
• pp.47-59
• /
• 2024

Purpose: This study aims to propose measures for the prevention of fire and explosion accidents within manufacturing facilities by improving the existing classification criteria for hazardous locations based on the leakage patterns of flammable liquids. The objective is to suggest ways to safely manage ignition sources and combustible materials. Method: The hazardous locations were calculated using "KS C IEC 60079-10-1," and the calculated explosion hazard distances were visualized in 3D. Additionally, the formula for the atmospheric dispersion of flammable vapors, as outlined in "P-91-2023," was utilized to calculate the dispersion rates within the hazardous locations represented in 3D. Result: Visualization of hazardous locations in 3D enabled the identification of blind spots in the floor plan, facilitating immediate recognition of ignition sources within these areas. Furthermore, when calculating the time taken for the Lower Explosive Limit (LEL) to reach within the volumetric space of the hazardous locations represented in 3D, it was found that the risk level did not correspond identically with the explosion hazard distances. Conclusion: Considering the atmospheric dispersion of flammable liquids, it was concluded that safety management should be conducted. Therefore, a method for calculating the concentration values requiring detection and alert based on realistically achievable ventilation rates within the facility is proposed.

• Journal of Chest Surgery
• /
• v.30 no.12
• /
• pp.1197-1204
• /
• 1997

Between April 1981 and June 1996, 65 patients had aortic root replacement at our institution. Disease entities were pure aortic annuloectasia in 31 patients(47.7%), Stanford type A aortic dissection with annuloectasia in 8(43.1%), atherosclerotic aneurysm with aortic regurgitation in 4(6.2%), and paravalvular leakage after aortic valve replacement in 2(3.1 %). 34 patients(52.3%) had the clinical stigmata of the Marfan syndrome. The operative procedures were Bentall operation in 61 patients(93.8%); 3 of conventional procedure and 58 of Cabrol's modification, aortic valve-sparing operation in 2(3.1 %), and root replacement with homograft in 2(3.1%). Hospital deaths occurred in 3 patients(4.8%) because of uncontrolled bleeding(1) and bypass weaning failure due to low cardiac output(2), and all had emergency operation with Cabrol's procedure. Postoperative complications developed in 19(29.2%) patients and most of them were transient. Surviving 62 patients have been followed up to cumulative total 315.0 patient-years(mean 60.2 $\pm$42.4 months). Late deaths occurred in 7 patients(11.3%), aneurysmal changes of remaining aorta were detected in 12 patients(19.4%). Actuarial survival rate at 10 years was 72.0 $\pm$ 9.7%, and the subsequent aortic operation-free rate at 10 years was 68.0$\pm$ 8.9% In a multivariate analysis, Marfan syndrome, emergency operation, preoperative dissection, combined arch replacement, and total circulatory arrest emerged as significant risk factors for hospital death or subsequent aortic operation. Over 60 years of age was the only risk factor for late death. Our 16 years'cummulative experience shows that aortic root replacement, mainly by means of Cabrol's procedure, can be applied successfully to variety of aortic root disease. However, long-term follow up will be needed to determine the late result of aortic valve-saving operation and root replacement with homograft. When dissection is present or the distal native aorta is diseased in'Marfan patients, close follow-up is necessary because of the subsequent aneurysmal change of remaining aorta.

• Journal of Chest Surgery
• /
• v.32 no.3
• /
• pp.281-286
• /
• 1999

Background: The purpose of this study is to analyze the types of complications, the incidences of complications, and preoperative and postoperative risk factors affecting the incidence of the complication. Material and Method: Between August 1990 and August 1997 in Asan Medical Center, 42 patients(24 men and 18 women) underwent surgical resection for pulmonary aspergilloma. The mean age was 46.6${\pm}$11.5 years(range 29 to 69 years). Hemoptysis(90%) was the most common presentation. Pulmonary tuberculosis was the most common predisposing cause(81%). The associated diseases were bronchiectasis(n=11), active puolmonary tuberculosis(n=9), diabetes mellitus(n=8), lung carcinoid(n=1), and acute myeloblastic leukemia(n=1). Lobectomy was done in 32 cases(76%), segmentectomy or wedge resection in 4, pneumonectomy in 2, and lobectomy combined with segmentectomy in 4. Result: Operative mortality was 2%. The most common postoperative complication was persistent air leakage(n=6). The variables such as age, sex, pulmonary function test, amount and duration of hemoptysis, associated diseases(diabetes mellitus, active pulmonary tuberculosis), mode of preoperative management(steroid, antifungal agent, bronchial arterial embolization), and modes of operative procedures were statistically insignificant. The radiologic extent of infiltration to normal lung parenchyme was statistically significant(p=0.04). Conclusion: We conclude that the extent of the infiltration to normal lung parenchyme in preoperative radiologic studies should be carefully evaluated to reduce the postoperative complications in surgery for pulmonary aspergilloma.