• Korean Security Journal
• /
• no.61
• /
• pp.87-107
• /
• 2019

With the government policy on converting contract workers to full-time employees, there have been significant changes about the security personnel at the nation's critical facilities, including the National Assembly Building and airports. Moreover, the scheduled disbandment of the conscripted police force in 2023 has raised concerns about security management at different government agencies. To examine the college students' perceptions on the possible alternatives to fill the expected security gap, 234 undergraduate students of security management and protection in the Seoul metropolitan region were surveyed. Particularly, a comparative analysis was conducted on the legal bases and supervision, the employment types and salaries, and the scopes of responsibility and authority of suggested alternatives were compared. The results showed that utilization of private police forces was thought to be the most effective option. Based on the research findings, the university departments should develop and maintain a quality curriculum to educate their students to be prepared security professionals with a focus on emergency response capabilities and martial arts, including the courses on private police law and emergency rescue and cardiopulmonary resuscitation (CPR).

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.32 no.5
• /
• pp.287-296
• /
• 2019

In this study, the effect of ground boundary conditions on the evaluation of blast resistance performance of precast arch structures was evaluated by a numerical analysis method. Two types of boundary conditions, namely, fixed boundary conditions and a perfectly matched layer (PML) were applied to numerical models. Blast loads that were much higher than the design load of the target structure were applied to compare the effects of the boundary conditions. The distribution and path of the ground explosion pressure, structural displacement, fracture of concrete, stress of concrete, and reinforcing bars were compared according to the ground boundary condition settings. As a result, the reflecting pressure shock wave at the ground boundaries could be effectively eliminated using PML elements; furthermore, the displacement of the foundation was reduced. However, no distinct difference could be observed in the overall structural behavior including the fracture and stress of the concrete and rebar. Therefore, when blast simulations are performed in the design of protective structures, it is rational to apply the fixed boundary condition on the ground boundaries as conservative design results can be achieved with relatively short computation times.

• Journal of the Korean Society of Radiology
• /
• v.15 no.5
• /
• pp.723-730
• /
• 2021

This study tries to compare dose distribution between arc radiation therapy and Tomotherapy, which are main radiation therapy modalities. The subjects of this study are lung cancer patients. For planning target volume (PTV), a dose of 60.0 Gy was set as a basis. The PTVmean of Arc was 61.04 Gy, and that of Tomotherapy was 58.50 Gy. The total lung capacities of Arc and Tomotherapy were 3.0 Gy and 4.24 Gy, respectively. The mean heart doses of Arc and Tomotherapy were 0.13 and 0.34, respectively; the mean trachea dose of Arc and Tomotherapy were 1.35 and 2.58, respectively; the mean esophagus dose of Arc and Tomotherapy were 0.41 and 0.86, respectively; the mean spinal cord dose of Arc and Tomotherapy were 3.65 and 4.68, respectively. With regard to the appropriateness of therapeutic effect in DHV, both modalities seemed appropriate. Tomotherapy protected normal tissues better than Arc radiation therapy. In Tomotherapy, patients need to have treatment long in a limited space. If such a point is overcome, Tomotherapy is better. Otherwise, Arc radiation therapy can be applied. This study was conducted with treatment planning images. Therefore, the results of this study are different from actual treatment results. If more research is conducted to overcome the limitation, the effects of radiation therapy are expected to increase further.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
• /
• v.9 no.1
• /
• pp.845-858
• /
• 2019

The most serious problem company facing in today's business environment is the failure of new product development outcomes. Statistically, almost half of the new products released each year failed. Despite the innovative technological advances, consumers' expectation level become much higher and global competition is intensifying. In addition, the new product life cycle is becoming shorter and shorter. It is difficult for a company to survive without developing long-lived products. The most important issue in a company's success and failure is the successful development and introduction of new products. Previous research has presented many determinants to achieve a successful new product development. This study focuses on dynamic competence as an important determinant, and identifies the constituting elements. Enterprises need to acquire, absorb, integrate and reconfigure their resources to survive and develop continuously. It is necessary to hold a dynamic ability switching resource bases in order to adapt to changing environments. The results of this study are as follows: First, the effect of learning, reconfiguration, and alliance capabilities on the new product development of small and medium-sized manufacturing enterprises seems to be positive. Second, the integrative and reconfiguration capabilities positively affect a new product development under high environmental turbulence.

• Fire Science and Engineering
• /
• v.32 no.6
• /
• pp.46-54
• /
• 2018

A total of 19 elevators for evacuation were installed in the Lotte World Tower and it is planned to operate the shuttle using the manual key from five refuge floors to the 1st floor in an emergency. In the event of a fire or other disaster, it is necessary to conduct intensive analysis to determine how much RSET reduction could be achieved using the evacuation elevator compared to the existing evacuation plans. When the optimal transportation sharing ratio by the evacuation elevators was 40% at the Lotte World Tower, the RSET of the evacuation scenario in parallel with the elevators in the entire building was calculated to be 1 hour and 2 minutes. The RSET of a conventional evacuation scenario (Walking along the stairs without using the elevators) was calculated to be 1 hour 29 minutes, therefore, the former evacuation scenario were found to have a shortening effect of approximately 27 minutes compared to the latter. On the other hand, to maintain this effect, each part of the evacuation route using the elevator must have the capability to protect the evacuee from any hazards caused by fires, such as smoke, flame, and radiant heat during the evacuation. Moreover, the evacuation route should be continuous from the residence position of the elevator user to the final evacuation site, and be recognized easily.

• Journal of the Korean Society of Radiology
• /
• v.13 no.3
• /
• pp.433-438
• /
• 2019

The medical institutions use radiation generating devices and radioactive isotopes to diagnose and treat patients. The patient transporter performs work in an environment that is more likely to be exposed to radiation when compared with the general public, such as inevitably entering the radiation management area for patient transfer, or transferring the isotope-administered patient at a short distance. For this reason, we conducted a study to determine the degree of exposure of the patient transporter. The 12 patient transporters working at Incheon A General Hospital are eligible. From April 1, 2019 to April 30, 2019, the dosimeter was used in the chest for one month and the accumulated dose was measured. The dosimeter used was a Optically Stimulated Luminescence Dosimetry (OSLD) and the dose reading was OSLD Microstar Reading System. As a result of cumulative dose measurement for one month, the average of the deep dose was 0.13 mSv and the surface dose was 0.13 mSv, and the cumulative dose for one month was multiplied by 12 to estimate the cumulative dose expectation As a result, the average of the deep dose and the surface dose were 1.52 mSv and 1.51 mSv, respectively. It is necessary to classify the patient transporter as a frequent visitor in order to measure and manage the exposure dose, increase the knowledge of protection against radiation through education and training, and prevent radiation trouble through medical examination.

• Journal of the Society of Disaster Information
• /
• v.18 no.4
• /
• pp.729-745
• /
• 2022

Purpose: This study collects basic data on the awareness of evacuation methods and evacuation facilities in the event of a radiological disaster of residents living in the emergency planning zone. Method: The residents of emergency planning zone were sampled using a random sampling method. A 1:1 interview was conducted using a structured questionnaire, and statistical analysis was performed using the minitab program. Result: First, the survey subjects showed a relatively low and negative awareness of the local government's work on radioactive disasters. Second, in terms of resident safety education, they had little experience in education, but they felt it was necessary and wanted education on evacuation methods, action tips, and the location of relief centers. Third, the location of the relief centers related to radioactive disasters was not well known, and there were many responses that they did not receive any guidance, and that they would be with their families when using the relief centers. Satisfaction levels were generally low with regard to the relief facilities. Fourth, the necessary priorities in preparation for radioactive disasters were education and training for radioactive disasters, facility supplementation, and supply of protective chemicals. Conclusion: The residents of emergency planning zone perceived the policies and tasks of the government or local governments relatively negatively in preparation for the occurrence of radioactive disasters, and their satisfaction was low. Regarding the matters pointed out as a priority, the government and local governments should publicize and educate the residents of accurate information and policies on radioactive disasters.

• Journal of the Korean Society of Radiology
• /
• v.17 no.2
• /
• pp.249-255
• /
• 2023

In this study, radiation exposure doses were measured in the course of clinical practice of radiation workers, radiological technologists in the radiation-related worker group, and preliminary-radiological technologists who were classified as frequent visitors. Radiological technologists who worked in the radiation area of C University Hospital in Incheon for a year from January 2021 and 121 students who completed clinical practice at the same medical institution from July 1 to August 31 were the subjects of the study. The nominal risk factor based on ICRP 103 was used to evaluate the probability of side effects due to the exposure dose to the lungs, which are organs at risk of damage due to radiation exposure dose. During the clinical practice period, radiology students, who were classified as frequent visitors, had a surface dose of 0.98 ± 0.14 mSv and a deep dose of 0.93 ± 0.14 mSv. In other words, 6.7 per 1,000,000 for shallow dose and 6.4 per 1,000,000 for deep dose were found to have side effects due to exposure to the lungs. This is a value in terms of exposure dose in one year. Considering that the radiation (science) education course is 3 or 4 years, systematic management and attention to prospective radiation workers who are going to clinical practice are required, and the stochastic effect of radiation In relation to this, it is considered that it will be used as basic data for radiation safety management.

• Journal of the Korean Society of Radiology
• /
• v.6 no.4
• /
• pp.281-290
• /
• 2012

The difference of radiation dose of MDCT due to different protocols between hospitals was analyzed by CTDI, DLP, the number of Slice and the number of DLP/Slice in 30 cases of the head, the abdomen and the chest that have 10 cases each from MDCT examination of the department of diagnostic imaging of three general hospitals in Gyeongsangbuk-do. The difference of image quality, CTDI, DLP, radiation dose in the eye and radiation dose in thyroid was analyzed after both helical scan and normal scan for head CT were performed because a protocol of head CT is relatively simple and head CT is the most frequent case. Head CT was significantly higher in two-thirds of hospitals compared to A hospital that does not exceed a CTDI diagnostic reference level (IAEA 50mGy, Korea 60mGy) (p<0.001). DLP was higher in one-third of hospitals than a diagnostic reference level of IAEA 1,050mGy.cm and Korea 1,000mGy.cm and two-thirds exceeded the recommendation of Korea and those were significantly higher than A hospital that does not exceed a diagnostic reference level (p<0.001). Abdomen CT showed 119mGy that was higher than a diagnostic reference level of IAEA 25mGy and Korea 20mGy in one-third. DLP in all hospitals was higher that Korea recommendation of 700mGy.cm. Among target hospitals, C hospital showed high radiation dose in all tests because MPR and 3D were of great importance due to low pitch and high Tube Curren. To analyze the difference of radiation dose by scan methods, normal scan and helical scan for head CT of the same patient were performed. In the result, CTDI and DLP of helical CT were higher 63.4% and 93.7% than normal scan (p<0.05, p<0.01). However, normal scan of radiation dose in thyroid was higher 87.26% (p<0.01). Beam of helical CT looked like a bell in the deep part and the marginal part so thyroid was exposed with low radiation dose deviated from central beam. In addition, helical scan used Gantry angle perpendicularly and normal scan used it parallel to the orbitomeatal line. Therefore, radiation dose in thyroid decreased in helical scan. However, a protocol in this study showed higher radiation dose than diagnostic reference level of KFDA. To obey the recommendation of KFDA, low Tube Curren and high pitch were demanded. In this study, the difference of image quality between normal scan and helical scan was not significant. Therefore, a standardized protocol of normal scan was generally used and protective gear for thyroid was needed except a special case. We studied a part of CT cases in the local area. Therefore, the result could not represent the entire cases. However, we confirmed that patient's radiation dose in some cases exceeded the recommendation and the deviation between hospitals was observed. To improve this issue, doctors of diagnostic imaging or technologists of radiology should perform CT by the optimized protocol to decrease a level of CT radiation and also reveal radiation dose for the right to know of patients. However, they had little understanding of the situation. Therefore, the effort of relevant agencies with education program for CT radiation dose, release of radiation dose from CT examination and addition of radiation dose control and open CT contents into evaluation for hospital services and certification, and also the effort of health professionals with the best protocol to realize optimized CT examination.

• Journal of Gastric Cancer
• /
• v.9 no.4
• /
• pp.172-176
• /
• 2009

Purpose: The rapid urease test is a rapid and reliable method for diagnosing Helicobacter pylori infection. However it requires gastric mucosal biopsies during endoscopy, and the test is not covered by national health insurance for patients with gastric cancer. So, we introduced an alternative method for a rapid urease test using back-table gastric mucosal biopsies from gastrectomy specimen. Materials and Methods: Ninety gastric cancer patients underwent an anti H. pylori IgG ELISA test and gastrectomy. Just after gastrectomy, two gastric mucosal biopsies from the prepyloric antrum and lower body of the gastrectomy specimen were taken from the back table in the operative room, and these were fixed immediately with the rapid urease test kit, and the color change was monitored for up to 24 hours. In this study, H. pylori infection was defined as positive when the serology or rapid urease test showed positive results. Results: The positive rate of the rapid urease test and serology was 91.1% and 77.8%, respectively. The sensitivity, specificity, positive predictive value and negative predictive value of the rapid urease test and serology were 94.3 and 80.5%, 100 and 100%, 100 and 100%, and 37.5 and 15%, respectively. The accuracy of the rapid urease test was higher than that of serology (94.4 vs. 81.1%, respectively). The rapid urease test showed a higher rate of detecting H. pylori infection than that of serology (McNemar's test, P=0.019). Conclusion: The result of the rapid urease test using back-table gastric mucosal biopsies from a gastrectomy specimen is comparable to the reference data of the conventional rapid urease test using gastric mucosal endoscopic biopsies. Therefore, it can be an alternative diagnostic method for H. pylori infection.