• Journal of Environmental Health Sciences
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• v.50 no.1
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• pp.36-42
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• 2024

Background: The use of scented candles and incense sticks, both of which are household products that are burned for indoor deodorization and calming effects, is increasing. Fine dust has been designated as a group 1 carcinogen by the International Agency for Research on Cancer. Volatile organic compounds (VOCs) affect air pollution and can cause diseases. Objectives: This study aims to determine the effect on indoor air quality by measuring PM_2.5 and VOCs generated when burning scented candles and incense sticks. Methods: Scented candles and incense sticks were selected as household products to burn. As for the target sample, top-selling products (five types of scented candles, five types of incense sticks) were purchased online. The PM_2.5 concentration according to time was measured immediately next to the sample and three meters away from each other in an enclosed space using a real-time aerosol photometer. VOCs were collected as samples under the same conditions using Tenax tubes and were quantitatively analyzed by TD-GC/MS. Results: In the case of scented candles, the concentration of PM_2.5 did not increase during combustion and after being extinguished by placing a cover on the candle. For the incense sticks, the concentration of PM_2.5 averaged 1,901.27 ㎍/m³. After burning scented candles and incense sticks, some VOCs concentrations were increased such as ethyl acetate and BTEX (benzene, toluene, ethylbenzene, xylene). Conclusions: Therefore, when using scented candles, extinguishment by placing a cover on the candle can be expected to reduce PM_2.5. It is advisable to avoid using incense sticks because PM_2.5 concentration increases from the start of combustion.

• Journal of Food Hygiene and Safety
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• v.39 no.2
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• pp.102-108
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• 2024

This study was performed to establish the epidemiological features of a food poisoning outbreak that occurred in the cafeteria of a company in Chungcheongnam-do Province, Korea, in October 2020, and to recommend measures to prevent similar outbreaks. Twenty-one patients with acute gastroenteritis, three food handlers, seven cooking utensils, and 12 preserved food samples were subjected to viral and bacterial analyses based on procedures described in the "Manual for Detection of Foodborne Pathogens at Outbreaks". Among 135 individuals who had been served the meals, 21 (15.6%) showed symptoms of nausea and vomiting within an hour of consuming the food. Bacillus cereus were isolated from 11 (52.4%) of the 21 patients, one food service employee, one item of cooking ware, and 12 preserved food samples. In addition, we confirmed the toxin genes CER, nheA, and entFM from the isolated B. cereus strains. Pulsed-field gel electrophoresis results indicated that all of the isolated B. cereus strains were closely related, with the exception of strains obtained from one patient and one sample of preserved food. These findings provide evidence to indicate that the isolated B. cereus originated from preserved foods and an unhygienic eating environment. This outbreak highlights that the provision of food in non-commercial food systems must be thoroughly managed. In addition, it emphasizes the necessity for the correct and timely identification of causal pathogens for tracing the cause of food poisoning outbreaks, and the need to preserve food under appropriate conditions. To prevent similar cases of food poisoning, it is necessary to investigate cases based on an epidemiological approach and share the findings.

• Journal of the Korean Institute of Landscape Architecture
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• v.52 no.3
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• pp.76-88
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• 2024

A significant cause of fall or overturning accidents in the construction industry, including landscaping construction and management, is work at heights using portable ladders. Portable ladders are classified as A-type or triangular support ladders depending on the number of supporting leg and support conditions. The tripod mobile ladder, which supports itself with only three supporting legs, is unstable and more prone to overturning compared to the A type ladders. Therefore, using the specifications of the tripod mobile ladder and the stability regulations of EN131-Part 7, overturning and resistance moment calculation formulas were derived for all directions in which overturning could occur. The moments calculated using these equations, and the overturning stability in each direction were evaluated. According to the calculation results, although there are differences depending on the direction, most are unstable for overturning at 8 or more steps. Based on these results, this study proposed measures to increase the moment of resistance by changing the weight, depth, and width, and using outriggers to ensure stability against the overturning of ladder. However, when changing the specifications of these measures, the size increases are excessive and the applicability is insufficient. On the other hand, outriggers are an applicable measure as they can ensure stability against overturning with only a minimum expansion length.

• Journal of Korean Society of Disaster and Security
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• v.16 no.4
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• pp.19-31
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• 2023

According to the climate change scenarios, the intensity of typhoons, a major factor in Korea's natural disaster, is expected to increase. The increase in typhoon intensity leads to a rise in wave heights, which is likely to cause large-scale disasters in coastal regions with high populations and building density for dwelling, industry, and tourism. This study, therefore, analyzed observation data of the Donghae ocean data buoy and conducted a numerical model simulation for wave estimations for the typhoon MAYSAK (202009) period, which showed the maximum significant wave height. The boundary conditions for wave simulations were a JMA-MSM wind field and a wind field applying the typhoon central pressure reduction rate in the SSP5-8.5 climate change scenario. As a result of the wave simulations, the wave height in front of the breakwater at Sokcho port was increased by 15.27% from 4.06 m to 4.68 m in the SSP5-8.5 scenario. Furthermore, the return period at the location of 147-2 grid point of deep-sea design wave was calculated to increase at least twice, it is necessary to improve the deep-sea design wave of return period of 50-year, which is prescriptively applied when designing coastal structures.

• Journal of the Korean Society of Radiology
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• v.82 no.6
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• pp.1570-1574
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• 2021

Post-partum galactocele is a common benign disease among breastfeeding women, whereas retromammary and peri-implant galactocele are relatively rare conditions. Herein, a 34-year-old, 1 month-postpartum female, who had augmentation mammoplasty and a 1-month history of breast pump use, presented with left breast enlargement for 2 weeks. An initial left breast US revealed hyperechoic peri-implant fluid collection. Additional US-guided fine needle aspiration was done using a 21G-needle, draining the milk component in the process, and cytologic results revealed numerous crystals, suggestive of galactocele. Various diseases, especially breast implant-associated anaplastic large cell lymphoma, can cause peri-implant fluid collection in an augmented breast. Thus, correlating imaging features with clinical information and cytologic analysis plays an important role in appropriate management.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.19 no.1
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• pp.93-105
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• 2024

Car-sharing is a representative model of the sharing economy, and it is a service that rents or uses a car for the necessary time without owning a car. This industry is growing due to various factors such as technological advances, increasing awareness of environmental protection, and increasing demand for solving traffic congestion problems in cities. Accordingly, there is a need for a strategic approach for companies providing car-sharing services to respond quickly to market changes in order to expand market share and differentiate services. Accordingly, this study conducted a case study on open innovation activities between Gongcar and existing rental car companies, focusing on the research question "What effects do open innovation activities between car-sharing companies and existing rental car companies cause?" As a result of the study, it was confirmed that Gongcar have (1) the ability to actively respond to market fluctuations by establishing a flexible vehicle supply chain based on demand, (2) have significantly reduced growth capital expenditure (Growth Capex), and both cafe and rental car companies have (3) performed successful open innovation by improving key KPI indicators and recording financial performance. This study reveals how open innovation acts as a key business growth engine in the car-sharing industry, and its significance is found in that it empirically confirmed the successful implementation conditions of open innovation based on resource dependence theory.

• Journal of Korean Tunnelling and Underground Space Association
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• v.26 no.4
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• pp.327-344
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• 2024

In general tunnel design and analysis, rock masses are often assumed to be isotropic. Under isotropic conditions, material properties are uniform in all directions, leading to a higher evaluation of tunnel stability. However, actual rock masses exhibit anisotropic characteristics due to discontinuities such as joints, bedding planes, and faults, which cause material properties to vary with direction. This anisotropy significantly affects the stress distribution during tunnel excavation, leading to non-uniform deformation and increased risk of damage. Therefore, thorough pre-analysis is essential. This study analyzes the displacement and stress changes occurring during tunnel excavation based on rock anisotropy. A three-dimensional numerical analysis was performed, selecting anisotropy index and dip angles as variables. The results showed that as the anisotropy index increased, the displacement in the tunnel increased, and stress concentration became more pronounced. The maximum displacement and shear stress were observed where the dip planes met the tunnel.

• Annals of Hepato-Biliary-Pancreatic Surgery
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• v.26 no.4
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• pp.386-394
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• 2022

Splenic artery steal syndrome (SASS) is a cause of graft hypoperfusion leading to the development of biliary tract complications, graft failure, and in some cases to retransplantation. Its management is still controversial since there is no universal consensus about its prophylaxis and consequently treatment. We present a case of SASS that occurred 48 hours after orthotopic liver transplantation (OLTx) in a 56-year-old male patient with alcoholic cirrhosis and severe portal hypertension, and who was successfully treated by splenic artery embolization. A literature search was performed using the PubMed database, and a total of 22 studies including 4,789 patients who underwent OLTx were relevant to this review. A prophylactic treatment was performed in 260 cases (6.2%) through splenic artery ligation in 98 patients (37.7%) and splenic artery banding in 102 (39.2%). In the patients who did not receive prophylaxis, SASS occurred after OLTx in 266 (5.5%) and was mainly treated by splenic artery embolization (78.9%). Splenic artery ligation and splenectomies were performed, respectively, in 6 and 20 patients (2.3% and 7.5%). The higher rate of complications registered was represented by biliary tract complications (9.7% in patients who received prophylaxis and 11.6% in patients who developed SASS), portal vein thrombosis (respectively, 7.3% and 6.9%), splenectomy (4.8% and 20.9%), and death from sepsis (4.8% and 30.2%). Whenever possible, prevention is the best way to approach SASS, considering all the potential damage arising from an arterial graft hypoperfusion. Where clinical conditions do not permit prophylaxis, an accurate risk assessment and postoperative monitoring are mandatory.

• Korean Circulation Journal
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• v.52 no.4
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• pp.304-319
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• 2022

Background and Objectives: De-escalation of dual-antiplatelet therapy through dose reduction of prasugrel improved net adverse clinical events (NACEs) after acute coronary syndrome (ACS), mainly through the reduction of bleeding without an increase in ischemic outcomes. Whether the benefits of de-escalation are sustained in highly thrombotic conditions such as ST-elevation myocardial infarction (STEMI) is unknown. We aimed to assess the efficacy and safety of de-escalation therapy in patients with STEMI or non-ST-segment elevation ACS (NSTE-ACS). Methods: This is a pre-specified subgroup analysis of the HOST-REDUCE-POLYTECH-ACS trial. ACS patients were randomized to prasugrel de-escalation (5 mg daily) or conventional dose (10 mg daily) at 1-month post-percutaneous coronary intervention. The primary endpoint was a NACE, defined as a composite of all-cause death, non-fatal myocardial infarction, stent thrombosis, clinically driven revascularization, stroke, and bleeding events of grade ≥2 Bleeding Academic Research Consortium (BARC) criteria at 1 year. Results: Among 2,338 patients included in the randomization, 326 patients were diagnosed with STEMI. In patients with NSTE-ACS, the risk of the primary endpoint was significantly reduced with de-escalation (hazard ratio [HR], 0.65; 95% confidence interval [CI], 0.48-0.89; p=0.006 for de-escalation vs. conventional), mainly driven by a reduced bleeding. However, in those with STEMI, there was no difference in the occurrence of the primary outcome (HR, 1.04; 95% CI, 0.48-2.26; p=0.915; p for interaction=0.271). Conclusions: Prasugrel dose de-escalation reduced the rate of NACE and bleeding, without increasing the rate of ischemic events in NSTE-ACS patients but not in STEMI patients.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.4
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• pp.567-575
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• 2024

The government and local governments are utilizing regulations, policies, and various project management techniques at each project stage to effectively and systematically manage public construction projects. However, the increase in construction costs continues to occur. In order to solve these problems, this study attempted to collect cases of existing public construction projects and analyze historical data. And it would like to derive the impact factor of increased construction costs. Based on the results, a plan was proposed to prevent the causes of increase and minimize in construction costs. The main reasons for the increase in costs were the occurrence of civil petition, differences between design documents and site conditions, and changes due to requests from the owner and changes in the business plan. And to solve these problems, this study proposed improvement for each cause from an institutional perspective, along with interview with experts and project owners. The results of this study are significant in improving the process of existing public construction process and presenting key inspection and review items for each major inspection stage in order to solve problem resulting from the analysis of the performance of public construction projects.