• Journal of Energy Engineering
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• v.26 no.2
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• pp.1-11
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• 2017

While they are becoming more viable, synthetic natural gas (SNG) plants, with their high temperatures and pressures, are still heavily dependent on advancements in the state-of-the-art technologies. However, most of the current work in the literature is focused on optimizing chemical processes and process variables, with little work being done on relevant mechanical damage and maintenance engineering. In this study, a combination of pipe system stress analysis and detailed local stress analysis was implemented to prioritize the inspection locations for main pipes of SNG plant in accordance to ASME B31.3. A pipe system stress analysis was conducted for pre-selecting critical locations by considering design condition and actual operating conditions such as heat-up and cool-down. Identified critical locations were further analyzed using a finite element method to locate specific high-stress points. Resultant stress values met ASME B31.3 code standards for the gasification reactor and lower transition piece (bend Y in Fig.1); however, it is recommended that the vertical displacement of bend Y be restricted more. The results presented here provide valuable information for future risk based maintenance inspection and further safe operation considerations.

• Information Systems Review
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• v.25 no.4
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• pp.27-45
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• 2023

The importance of information security has grown alongside the development of information and communication technology. However, companies struggle to select suitable countermeasures within their limited budgets. Sönmez and Kılıç (2021) proposed a model using AHP and mixed integer programming to determine the optimal investment combination for mitigating information security breaches. However, their model had limitations: 1) a lack of objective measurement for countermeasure efficacy against security threats, 2) unrealistic scenarios where risk reduction surpassed pre-investment levels, and 3) cost duplication when using a single countermeasure for multiple threats. This paper enhances the model by objectively quantifying countermeasure efficacy using the beta probability distribution. It also resolves unrealistic scenarios and the issue of duplicating investments for a single countermeasure. An empirical analysis was conducted on domestic SMEs to determine investment budgets and risk levels. The improved model outperformed Sönmez and Kılıç's (2021) optimization model. By employing the proposed effectiveness measurement approach, difficulty to evaluate countermeasures can be quantified. Utilizing the improved optimization model allows for deriving an optimal investment portfolio for each countermeasure within a fixed budget, considering information security costs, quantities, and effectiveness. This aids in securing the information security budget and effectively addressing information security threats.

• Korean Journal of Construction Engineering and Management
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• v.15 no.3
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• pp.23-30
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• 2014

Overseas construction orders of domestic companies had been increased significantly in a short period from $10.9 billion in 2005 to $64.9 billion in 2012. However experts are concerned that quality of growth will not support quantitative growth. This study suggest concentrate competencies for not only winning in bid but also successful execution of domestic companies. 4 Steps which are Pre-Marketing, Bid-Preparation, Bidding, Contract Phase are defined for competency assessment. After drawing specific tasks by phase, survey asking importance and capability of the tasks to the person in charge of bidding and site was conducted by utilizing Likert 7 point scale. According to the result of IPA analysis, domestic construction companies need to ensure internal competencies; Project risk review, Bid team organization, and external competencies; Client needs grasp, Localization strategy, Cooperation establishment. Hearafter domestic construction companies will be able to utilize the result of the study for setting bidding strategy for winning in bid and improving earning rate.

• Journal of Food Hygiene and Safety
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• v.34 no.3
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• pp.283-289
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• 2019

This study was performed to monitor the residual pesticides in agricultural products used in school foodservice in the Gwangju metropolitan area. Risk assessment was also carried out based on the amount of agricultural products consumed. A total of 320 agricultural products supplied to schools in Gwangju were analyzed from 2015 to 2017. The pre-treatment and residual pesticide analysis of these products was conducted in accordance with the second method for multi-residue analysis of pesticides in the Korean food code. The hazard index was calculated by dividing the estimated daily intake (EDI) of pesticides by the acceptable daily intake (ADI). The linearity correlation coefficient for the calibration curve was 0.9923 to 1.0000, LOD 0.004 to 0.019 mg/kg, LOQ 0.012 to 0.057 mg/kg, and recovery was 79.1 to 100.2%. Residual pesticides were detected in 18 (5.6%) of 320 agricultural products used for school foodservice, and one sample of sweet potato stem (0.3%) exceeded the maximum residual limit (MRL). The detection frequency for chili peppers and bell peppers was higher than that for other agricultural products. The frequently-detected pesticides were boscalid and acetamiprid. These results showed that residual pesticide management is needed for chili pepper, bell pepper and sweet potato stem among agricultural products supplied to schools. The hazard index of bifenthrin in sweet potato stem showed the highest (64.18%), and the other pesticides were 0.03-8.23%. These results indicated that agricultural products supplied to schools in Gwangju were safe for consumption. To minimize the intake of residual pesticides, it is necessary to not only thoroughly wash agricultural products but to also ensure the expanded supply of products that are pesticide-free.

• Journal of Nutrition and Health
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• v.56 no.2
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• pp.155-167
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• 2023

Purpose: This study investigates the association between seafood consumption and frailty according to gender in the Korean elderly. Methods: Cross-sectional data from the Seventh (2016-2018) Korea National Health and Nutrition Examination Survey was procured for this study. Data from 3,675 subjects (1,643 men and 2,032 women) aged ≥ 65 years were analyzed. Levels of seafood intake were assessed by a one-day 24-hour dietary recall, and subjects were classified into three tertiles by gender according to frailty phenotype: robust, pre-frail, and frail. Multinomial logistic regression analysis was performed to clarify the association between seafood consumption and frailty for each gender. Results: The prevalence of frailty was determined as 13.4% for men and 29.7% for women. Participants with a higher seafood intake had higher intakes of grains, fruits, and vegetables, while the intake of meat was significantly lower. In both men and women, the group with higher seafood intake showed higher energy and micronutrient intakes. The frail prevalence and frailty score were significantly low in the highest tertiles of seafood consumption compared to the lowest tertile in men and women (p < 0.001). After adjusting for confounder, the highest tertile of seafood consumption showed a decreased risk of frailty compared to the lowest tertile only in women (hazard ratio [HR], 0.50; 95% confidence interval [CI], 0.32-0.78; p-trend = 0.008 vs. HR, 0.52; 95% CI, 0.32-0.83; p-trend = 0.008; respectively). Conclusion: Results of this study suggest that seafood consumption potentially decreases the risk of frailty in the elderly.

• Asian Spine Journal
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• v.12 no.6
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• pp.1043-1052
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• 2018

Study Design: Level III retrospective cross-sectional study. Purpose: To define and characterize the presentation, symptom duration, and patient/surgical risk factors associated with 'post-decompressive neuropathy (PDN).' Overview of Literature: PDN is characterized by lower extremity radicular pain that is 'different' from pre-surgical radiculopathy or claudication pain. Although it is a common constellation of postoperative symptoms, PDN is incompletely characterized and poorly understood. We hypothesize that PDN is caused by an intraoperative neuropraxic event and may develop early (within 30 days following the procedure) or late (after 30 days following the procedure) within the postoperative period. Methods: Patients who consented to undergo lumbar laminectomy with or without an instrumented fusion for degenerative lumbar spine disease were followed up prospectively from July 2013 to December 2014. Relevant data were extracted from the charts of the eligible patients. Patient demographics and surgical factors were identified. Patients completed postoperative questionnaires 3 weeks, 3 months, 6 months, and 1 year postoperatively. Questions were designed to characterize the postoperative pain that differed from preoperative pain. A diagnosis of PDN was established if the patient exhibited the following characteristics: pain different from preoperative pain, leg pain worse than back pain, a non-dermatomal pain pattern, and nocturnal pain that often disrupted sleep. A Visual Analog Scale was used to monitor the pain, and patients documented the effectiveness of the prescribed pain management modalities. Patients for whom more than one follow-up survey was missed were excluded from analysis. Results: Of the 164 eligible patients, 118 (72.0%) completed at least one follow-up survey at each time interval. Of these eligible patients, 91 (77.1%) described symptoms consistent with PDN. Additionally, 75 patients (82.4%) described early-onset symptoms, whereas 16 reported symptoms consistent with late-onset PDN. Significantly more female patients reported PDN symptoms (87% vs. 69%, p=0.03). Patients with both early and late development of PDN described their leg pain as an intermittent, constant, burning, sharp/stabbing, or dull ache. Early PDN was categorized more commonly as a dull ache than late-onset PDN (60% vs. 31%, p=0.052); however, the difference did not reach statistical significance. Opioids were significantly more effective for patients with early-onset PDN than for those with late-onset PDN (85% vs. 44%, p=0.001). Gabapentin was most commonly prescribed to patients who cited no resolution of symptoms (70% vs. 31%, p=0.003). Time to symptom resolution ranged from within 1 month to 1 year. Patients' symptoms were considered unresolved if symptoms persisted for more than 1 year postoperatively. In total, 81% of the patients with early-onset PDN reported complete symptom resolution 1 year postoperatively compared with 63% of patients with late-onset PDN (p=0.11). Conclusions: PDN is a discrete postoperative pain phenomenon that occurred in 77% of the patients who underwent lumbar laminectomy with or without instrumented fusion. Attention must be paid to the constellation and natural history of symptoms unique to PDN to effectively manage a self-limiting postoperative issue.

• Journal of Korean Foot and Ankle Society
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• v.17 no.1
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• pp.23-27
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• 2013

Purpose: The optimal management for ankle fracture in elderly patients remains controversial. This study was undertaken to review the results of surgical treatment of ankle fracture in the elderly and to compare with other studies. Materials and Methods: The participants in this study were 33 patients over the age of 65(average 71.5 years) who underwent surgical treatment of ankle fracture from January 2004 to December 2011. The study was a retrospective review of outcomes after open reduction and internal fixation (ORIF) of ankle fractures. To measure the clinical outcomes, we assessed postoperative complications, the pre- and post-operative mobility status, fracture union status, the time of fracture union and the AOFAS (American Orthopaedic Foot and Ankle Society) Ankle-Hindfoot scale. The level of patient satisfaction was also identified. Results: Delayed wound healing occurred in three patients(9.1%) but their wounds healed with repeated dressings without additional surgical treatment. Malunion occurred in one patient(3%). One patient(3%) had postoperative infection but healed with antibiotic treatment. 24 patients(96%) returned to preoperative mobility status. VAS score was lower than 2 in all patients. Bone union occurred with the 3.8 months (average months) after the surgery in all patients. Average AOFAS score was 87.4 and these were similar results as other studies of young patients. All patients were satisfied with surgical outcomes according to interviews. Conclusion: Surgical treatment of ankle fractures in the elderly can carry a significant risk of delayed wound healing and infection but incidence is relatively low. Internal fixation of ankle fractures in the elderly can be undertaken safely and the majority of patients can expect good outcome.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.1
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• pp.33-40
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• 2021

In recent years, many construction projects become large and complicated, and construction accidents also steadily increase, which grows interest in the safety and maintenance during construction. Many of the construction accidents are related to temporary construction and structures, but the safety evaluation and management during construction are unclear and indefinite due to the short operating period and continuous change in the formation of the temporary structure. The system support, which is one of the temporary structures to support the pouring load of concrete, was proposed to easily install and dismantle members with connection parts pre-manufactured. The use of the system support is increasing to improve the safety of the temporary structure during construction. However, the system support, which consists of multiple members, still has uncertainties in connectivity between members and supports of vertical members. Therefore, this study analyzed the structure, load, and accident cases of the system support to define the damage scenarios for member connection, support condition, and lateral displacement. The decrease rate of the critical load was analyzed according to the damage scenarios based on the defined unit structure of the system support. In addition, this study provided vulnerable members for each damage scenario, which could induce instability of the temporary structures during design, construction, and operation of the structure.

• Journal of Chest Surgery
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• v.38 no.2 s.247
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• pp.146-151
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• 2005

Background: Preoperative elevated serum creatinine values are associated with increased risk for both morbidity and mortality in patients undergoing on-pump coronary artery bypass surgery (CABG). We investigated the postoperative changes of renal function and proper management in the patients. Material and Method: Among 74 consecutive patients who underwent isolated on-pump CABG, 17 patients with increased serum creatinine level $(creatinine\;\geqq\;1.5\;mg/dL)$ within preoperative one week wereincluded in the study. Seven patients showed pre­operative serum creatinine level of 2.0 mg/dL or higher, and 3 of them had been undergoing hemodialysis. Preoperative hemodialysis was performed in the 3 patients due to end-stage renal failure (ESRD) the day before the operation. We started peritoneal dialysis immediately after the cardiopulmonary bypass in patients with ESRD or postoperative acute renal failure if it was necessary to remove intravascular volume and lower serum creatinine level. Result In most of the patients with CABG, postoperative serum creatinine level increased and recovered to the preoperative level at the discharge. In 2 of the 4 patients with serum creatinine level of 2.0 mg/dL or higher and 3 patients with ESRD, intravascular volume, serum creatinine level and serum electrolyte were controlled with peritoneal dialysis. Conclusion: Postoperative serum creatinine level increased transiently in most of CABG patients, and intravascular volume and serum creatinine level were controlled by peritoneal dialysis only in the patients with acute renal failure postoperatively and those depending on hemodialysis.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.2
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• pp.206-225
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• 2012

General status of pediatric dentistry in Korea is to conduct vigorous academic activities and specialized medical care centering the Korean Association of Pediatric Dentistry (KAPD) that has about 1,000 pediatric dentists as members, pediatric dentistry departments of 11 Colleges of Dentistry, numbers of pediatric dentistry training institutions and private clinics specialized in children. From 1996, the accredited pediatric dentists were produced by the KAPD and from 2008, the state began to produce the accredited pediatric dentists. Since then, doctors with expertise in pediatric care had opened private clinics in addition to the university hospitals, it became the basis of a momentum to deepen the specialty of pediatric dentistry. The Dentistry community of Korea is going through rapid and profound changes recently, and the underlying reasons for such changes can be classified largely into a few categories: (1) Decreasing population and structural changes in population (2) Increase in numbers of dentists, (3) Changes in the pattern of dental diseases and (4) Changes in medical environment. In Korea, the children population in the age range of 0 ~ 14 years old had been decreased by 2 million in 2010 compared to that of 2000 due to reduction of birth rate. The current population of children in the age range of 0 ~ 4 years old in 2010 takes up 16.2% of the total population, but it is estimated that such percentage would decrease to 8.0% by 2050. Such percentage is largely behind the estimated mean global population of 19.6% by 2050. On the other hand, the number of dentists had been largely increased from 18,000 in 2000 to 25,000 in 2010. And it is estimated that the number will be increased to 41,000 by 2030. In addition, the specialized personnel of Pediatric dentistry had been shown as increased by 2.5 times during past 10 years. For the changes in the pattern of dental diseases, including dental caries, each df rate of 5 years old children and 12 years old children had been decreased by 21.9% and 16.7% respectively in 2010 compared to 2000. Each df Index also had been decreased by 2.5 teeth and 1.2 teeth respectively. The medical expenditure of Korea is less than that of OECD and more specifically, the expenditure from the National Health Plan is less than OECD but the expenditure covered by households is larger than OECD. These facts indicate that it is considered as requiring the coverage of the national health plan to be reinforced more in the future and as such reinforcement needs continuous promotion. In medical examination pattern of Pediatric dentistry, the preventive and corrective treatment were increased whereas the restorative treatment was decreased. It is considered that such change is caused from decrease of dental caries from activation of the prevention project at national level. For the restorative treatment, the restorations in use of dental amalgam, pre-existing gold crowning and endodontic treatment had been decreased in their proportion while the restorative treatment in use of composite resin had been increased. It is considered that such changes is caused by the change of demands from patients and family or guardians as they desired more aesthetic improvement along with socio-economic growth of Korean society. Due to such changes in dentistry, the pediatric dentistry in Korea also attempts to have changes in the patterns of medical examination as follows; It tends to implement early stage treatment through early diagnosis utilizing various diagnostic tools such as FOTI or QLF. The early stage dental caries so called white spot had been included in the subjects for dental care or management and in order to do so, the medical care guidelines essentially accompanied with remineralization treatment as well as minimally invasive treatment is being generalized gradually. Also, centering the Pediatric dentists, the importance of caries risk assessment is being recognized, in addition that the management of dental caries is being changed from surgical approach to internal medicinal approach. Recently, efforts began to emerge in order to increase the target patients to be managed by dentists and to expand the application scope of Pediatric dentistry along with through such changes. The interest and activities of Pediatric dentists which had been limited to the medical examination room so far, is now being expanded externally, as they put efforts for participating in the preventive policy making process of the community or the state, and to support the political theories. And also opinions are being collected into the direction that the future- oriented strategic political tasks shall be selected and researches as well as presentations on the theoretical rationale of such tasks at the association level.