• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.44 no.6
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• pp.275-281
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• 2018

Objectives: Isolated mandibular fractures contribute to approximately 45% of maxillofacial traumas. Improper management of mandibular fractures can cause myriad potential complications and can lead to serious functional and aesthetic sequelae. The objective of the study is to design a stepwise approach for managing isolated mandibular fractures using open reduction and internal fixation (ORIF) with regional anesthesia on outpatient basis. Materials and Methods: Patients with isolated mandibular fractures presenting to the department of maxillofacial surgery were selected for ORIF under regional anesthesia based on occlusion, age, socioeconomic status, general condition, habits, and allied medical ailments. Standard preoperative, intraoperative, and postoperative protocols were followed. All patients were followed up for a minimum of 4 weeks up to a maximum of 1 year. Results: Of 23 patients who received regional anesthesia, all but one had good postoperative functional occlusion. One patient was hypersensitive and had difficulty tolerating the procedure. Two patients developed an extraoral draining sinus, one of whom was managed with local curettage, while the other required hardware removal. One patient, who was a chronic alcoholic, returned 1 week after treatment with deranged fracture segments after he fell while intoxicated. Conclusion: With proper case selection following a stepwise protocol, the majority of mandibular fractures requiring ORIF can be managed with regional anesthesia and yield minimal to no complications.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.10
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• pp.1353-1358
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• 2021

IoT (Internet of Things) emerges from various technologies such as communications, micro processors and embedded system and so on. The IoT has also been used to UAV (Unmanned Aerial Vehicle) system. In manned aircraft, a pilot and co-pilot should control FCS (Flight Control System) with FBW(Fly By Wire) system for flight operation. In contrast, the flight operation in UAV system is remotely and fully managed by GCS (Ground Control System) almost in real time. To make it possible the communication channel should be necessary between the UAV and the GCS. There are many protocols between two systems. Amongst them, MAVLink (Macro Air Vehicle Link) protocol is representatively used due to its open architecture. MAVLink does not define any securities itself, which results in high vulnerability from external attacks. This paper proposes the method to enhance data security in GCS network by applying cryptographic methods to the MAVLink messages in order to support safe UAV operations.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.3
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• pp.547-554
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• 2022

Recently, the field of telemedicine is growing rapidly due to the COVID-19 pandemic. However, the cost of telemedicine services is relatively high, since cloud computing, video conferencing, and cyber security should be considered. Therefore, in this paper, we design and implement a cost-effective P2P-based telemedicine system. It is implemented using the widely used the open source computing platform, Raspberry Pi, and P2P network that frees users from security problems such as the privacy leakage by the central server and DDoS attacks resulting from the server/client architecture and enables trustworthy identifying connection system using SSL protocol. Also it enables users to check the other party's status including body temperature in real time by installing a thermal imaging camera using Raspberry Pi. This allows several medical diagnoses that requires visual aids. The proposed telemedicine system will popularize telemedicine service and meet the ever-increasing demand for telemedicine.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.5
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• pp.737-750
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• 2022

The demands of Unmanned Aerial Vehicles (UAVs) are growing very rapidly with the era of the 4th industrial revolution. As the technology of the UAV improved with the development of artificial intelligence and semiconductor technology, it began to be used in various civilian fields such as hobbies, bridge inspections, etc from being used for special purposes such as military use. MAVLink (Macro Air Vehicle Link), which started as an open source project, is the most widely used communication protocol between UAV and ground control station. However, MAVLink does not include any security features such as encryption/decryption mechanism, so it is vulnerable to various security threats. Therefore, in this study, the block cipher is implemented in UAV to ensure confidentiality, and the results of the encryption and decryption performance evaluation in the UAV according to various implementation methods are analyzed. In addition, we proposed the security requirements in accordance with Common Criteria, which is an international recognized ISO standard.

• Journal of Dental Anesthesia and Pain Medicine
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• v.22 no.2
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• pp.75-86
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• 2022

This review aims to identify the influence of the vehicle and its concentration used to carry calcium hydroxide (Ca(OH)₂) medicament on postoperative pain. The protocol for this review was registered in the open science framework (Registration DOI-10.17605/OSF.IO/4Y8A9) and followed the guidelines provided by the Joanna Briggs Institute. Reporting was based on the preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews (PRISMA-ScR). Literature screening and searches were performed on PubMed/Medline, Scopus, and EBSCO hosts. Furthermore, additional records were manually analyzed using various sources. The selected studies were published in English and included the use of any vehicle adjunct to Ca(OH)₂ to evaluate postoperative pain using qualitative and quantitative pain assessment tools. Descriptive analysis was conducted to review the study design, vehicle elements, and their effects. A preliminary search yielded 7584 studies, of which 10 were included. According to the data collected, the most commonly used Ca(OH)₂ vehicles were chlorhexidine (CHX), normal saline, and camphorated paramonochlorophenol/glycerine (CPMC/glycerine), which had a significant effect on postoperative pain. Among the included studies, six evaluated the effect of CHX as a vehicle. It was observed that a higher concentration of the vehicle (2%) showed a favorable response in reducing postoperative pain. A majority of studies have validated a positive consequence of using a vehicle on postoperative pain. Although higher vehicle concentrations were found to alter postoperative pain levels, the data were insufficient to draw a firm conclusion. Our scoping review indicates that further clinical studies should focus on using different vehicles at various concentrations and application times to check for feasible and safe exposure in addition to providing pain relief.

• International Journal of Computer Science & Network Security
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• v.24 no.3
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• pp.23-28
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• 2024

The multi-tenancy and high scalability of the cloud have inspired businesses and organizations across various sectors to adopt and deploy cloud computing. Cloud computing provides cost-effective, reliable, and convenient access to pooled resources, including storage, servers, and networking. Cloud service models, SaaS, PaaS, and IaaS, enable organizations, developers, and end users to access resources, develop and deploy applications, and provide access to pooled computing infrastructure. Despite the benefits, cloud service models are vulnerable to multiple security and privacy attacks and threats. The SaaS layer is on top of the PaaS, and the IaaS is the bottom layer of the model. The software is hosted by a platform offered as a service through an infrastructure provided by a cloud computing provider. The Hypertext Transfer Protocol (HTTP) delivers cloud-based apps through a web browser. The stateless nature of HTTP facilitates session hijacking and related attacks. The Open Web Applications Security Project identifies web apps' most critical security risks as SQL injections, cross-site scripting, sensitive data leakage, lack of functional access control, and broken authentication. The systematic literature review reveals that data security, application-level security, and authentication are the primary security threats in the SaaS model. The recommended solutions to enhance security in SaaS include Elliptic-curve cryptography and Identity-based encryption. Integration and security challenges in PaaS and IaaS can be effectively addressed using well-defined APIs, implementing Service Level Agreements (SLAs), and standard syntax for cloud provisioning.

• Korean Journal of Radiology
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• v.22 no.4
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• pp.535-546
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• 2021

Objective: To evaluate the feasibility of texture analysis on non-contrast-enhanced T1 maps of cardiac magnetic resonance (CMR) imaging for the diagnosis of myocardial injury in acute myocardial infarction (MI). Materials and Methods: This study included 68 patients (57 males and 11 females; mean age, 55.7 ± 10.5 years) with acute ST-segment-elevation MI who had undergone 3T CMR after a percutaneous coronary intervention. Forty patients of them also underwent a 6-month follow-up CMR. The CMR protocol included T2-weighted imaging, T1 mapping, rest first-pass perfusion, and late gadolinium enhancement. Radiomics features were extracted from the T1 maps using open-source software. Radiomics signatures were constructed with the selected strongest features to evaluate the myocardial injury severity and predict the recovery of left ventricular (LV) longitudinal systolic myocardial contractility. Results: A total of 1088 segments of the acute CMR images were analyzed; 103 (9.5%) segments showed microvascular obstruction (MVO), and 557 (51.2%) segments showed MI. A total of 640 segments were included in the 6-month follow-up analysis, of which 160 (25.0%) segments showed favorable recovery of LV longitudinal systolic myocardial contractility. Combined radiomics signature and T1 values resulted in a higher diagnostic performance for MVO compared to T1 values alone (area under the curve [AUC] in the training set; 0.88, 0.72, p = 0.031: AUC in the test set; 0.86, 0.71, p = 0.002). Combined radiomics signature and T1 values also provided a higher predictive value for LV longitudinal systolic myocardial contractility recovery compared to T1 values (AUC in the training set; 0.76, 0.55, p < 0.001: AUC in the test set; 0.77, 0.60, p < 0.001). Conclusion: The combination of radiomics of non-contrast-enhanced T1 mapping and T1 values could provide higher diagnostic accuracy for MVO. Radiomics also provides incremental value in the prediction of LV longitudinal systolic myocardial contractility at six months.

• Annals of Hepato-Biliary-Pancreatic Surgery
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• v.28 no.2
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• pp.238-247
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• 2024

Backgrounds/Aims: Prolonged use of steroids after liver transplantation (LT) significantly increases the risk of diabetes or cardiovascular disease, which can adversely affect patient outcomes. Our study evaluated the effectiveness and safety of early steroid withdrawal within the first year following LT. Methods: This study was conducted as an open-label, multicenter, randomized controlled trial. Liver transplant recipients were randomly assigned to one of the following two groups: Group 1, in which steroids were withdrawn two weeks posttransplantation, and Group 2, in which steroids were withdrawn three months posttransplantation. This study included participants aged 20 to 70 years who were scheduled to undergo a single-organ liver transplant from a living or deceased donor at one of the four participating centers. Results: Between November 2012 and August 2020, 115 patients were selected and randomized into two groups, with 60 in Group 1 and 55 in Group 2. The incidence of new-onset diabetes after transplantation (NODAT) was notably higher in Group 1 (32.4%) than in Group 2 (10.0%) in the per-protocol set. Although biopsy-proven acute rejection, graft failure, and mortality did not occur, the median tacrolimus trough level/dose/weight in Group 1 exceeded that in Group 2. No significant differences in safety parameters, such as infection and recurrence of hepatocellular carcinoma, were observed between the two groups. Conclusions: The present study did not find a significant reduction in the incidence of NODAT in the early steroid withdrawal group. Our study suggests that steroid withdrawal three months posttransplantation is a standard and safe immunosuppressive strategy for LT patients.

• Journal of the Korean Society of Radiology
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• v.6 no.4
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• pp.281-290
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• 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 the Korea Society of Computer and Information
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• v.16 no.5
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• pp.79-91
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• 2011

In this paper, a DS (Data Synchronization) server for mobile communication environments is constructed and the suitability and the performance of its operations are validated. The DS server provides a way to update the newest data and keep data consistency for clients (mobile devices). In addition, the DS server constructed in this paper supports various synchronization types, and detects all changes and conflicts. In case of data conflicts, the DS server resolves the conflicts according to the several policies implemented in this work. The DS server conforms to the OMA(Open Mobile Alliance) DS standard protocol for interoperability with other mobile devices and servers. In addition to the transmission-by record scheme proposed by the OMA DS standard protocol, the DS server constructed in this paper also provides the transmission-by field scheme for the enhancement transmission performance between the server and clients. In order to validate its operations, data synchronization between the DS server and the SCTS (SyncML Conformance Test Suit), the suitability validation tool provided by the OMA, is performed. The validation results show that the DS server constructed in this paper satisfies all of the test cases except the Large Object function. The Large Object function will be implemented later because the function is not needed for the personal information synchronization process which this paper aims for. Also, synchronization times of the DS server are measured while increasing the number of data and clients. The results of the performance evaluations demonstrate that the DS server is scalable, in the sense that it has not suffered from any serious bottlenecks with respect to the number of data and clients. We expect that this work will provide a framework for various studies in the future for improving mobile DS operations.