• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.8
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• pp.942-949
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• 2012

In order to ensure the safety of the large-scale public facilities, the analysis of EMC(ElectroMagnetic Compatibility) of electronic systems included in the facilities is very necessary. The reason is that the system-level EMC of the facility could be not guaranteed, even if individual equipments included in the facility are satisfied with their EMC requirements. As a result, the system-level evaluation and analysis of EMC should be carried out in order to establish the reliable operations of safety and mission-critical electronic systems. This paper analyze the relevant legal systems of domestic and other countries, and furthermore case studies of system-level EMC approaches were analyzed in the specific applications of electric railways, building, automobile, petroleum refinery systems. And the introduction of related systems in Korea is proposed, and main parts and problems to be looked at each proposed measures are discussed. The results are expected to be utilized in the introduction of the system-level EMC engineering, and contributed in national security and the protection of people's life, body and their properties.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.79-82
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• 2012

최근 지진해일 발생으로 인한 막대한 피해로 인해 지진해일 방재에 대한 중요성이 높아지고 있다. 지진해일 방재연구는 주로 실제 발생하였던 역사지진해일과 발생가능성이 높은 가상의 지진해일에 대해 해당지역의 재해정보도를 제작하여, 지진해일 발생 시 인명 및 재산피해를 최소화 하는 것에 초점이 맞추어져 있다. 따라서 이번 연구에서는 이러한 재해정보도의 효율성을 높이기 위해 지진해일 발생 시 인명피해가 발생할 가능성이 높은 위험지역을 선정하였다. 지진해일 위험지역을 선정하기 위해 가상의 지진해일을 수치모의 하였으며, 지진해일 발생 시 인명피해가 발생할 수 있는 지진해일 범람 높이를 선정하여 선정한 기준 높이 이상의 범람이 발생할 확률을 계산하였다. 지진해일 수치모의는 지진해일 전파모의와 범람모의 과정으로 이루어진다. 지진해일 전파모형은 선형 Boussinesq 방정식을 지배방정식으로 사용하며, 지진해일 범람모형은 비선형 천수방정식을 지배방정식으로 사용하였다. 수치모의를 통해 주문진항에서의 가상의 지진해일에 대한 범람영역 및 범람 높이를 얻었다. 수치모의를 통해 얻어진 범람 데이터를 이용해 기준 높이 이상의 범람 발생 확률을 계산하였다. 확률 계산을 위해선 해당 데이터의 확률분포를 결정하여야 하기 때문에, 적합도 검정을 수행하였다. 이번 연구에서는 여러 가지 적합도 검정 기법 중 하나인 확률도시 상관계수 검정(Probability Plot Correlation Coefficient Test)을 사용하였으며, 범람 데이터의 확률분포로 Normal, Log-normal, Exponential, Gumbel 분포를 가정하여 검정을 수행하였다. 각 지점별로 확률도시 상관계수 검정을 수행하여, 해당 지점의 확률분포를 결정하였고, 각 지점별로 해당하는 확률분포의 누적확률분포 함수를 이용해 기준 높이 이상의 범람이 발생할 확률을 계산하였다. 얻어진 확률을 지도상에 도시하여 기준 높이 이상의 범람 발생 확률이 높은 지점을 주문진항에서의 지진해일에 대한 인명피해 발생 가능성이 높은 위험지역으로 선정하였다.

• Journal of the Korean Dietetic Association
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• v.25 no.1
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• pp.30-43
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• 2019

This study compared the predictive models for the growth kinetics of Staphylococcus aureus in ham rice balls. In addition, a semi-quantitative risk assessment of S. aureus on ham rice balls was conducted using FDA-iRISK 4.0. The rice was rounded with chopped ham, which was mixed with mayonnaise (SHM), soy sauce (SHS), or gochujang (SHG), and was contaminated artificially with approximately $2.5{\log}\;CFU{\cdot}g^{-1}$ of S. aureus. The inoculated rice balls were then stored at $7^{\circ}C$, $15^{\circ}C$, and $25^{\circ}C$, and the number of viable S. aureus was counted. The lag phases duration (LPD) and maximum specific growth rate (SGR) were calculated using a Baranyi model as a primary model. The growth parameters were analyzed using the polynomial equation as a function of temperature. The LPD values of S. aureus decreased with increasing temperature in SHS and SHG. On the other hand, those in SHM did not show any trend with increasing temperature. The SGR positively correlated with temperature. Equations for LPD and SGR were developed and validated using $R^2$ values, which ranged from 0.9929 to 0.9999. In addition, the total DALYs (disability adjusted life years) per year in the ham rice balls with soy sauce and gochujang was greater than mayonnaise. These results could be used to calculate the expected number of illnesses, and set the hazard management method taking the DALY value for public health into account.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.1
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• pp.90-96
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• 2019

Storage cabinet in a lab in these days measures various environmental factors in real-time with IoT sensors. Preexisting system collects sensor data, analyze a risk and then command other equipment. Such centralized control system tends to have an issue with of speed slowing down. It's because when there are more storage cabinets, there are more data to process. In order to solve this issue, this report addresses decentralized IoT sensor based lab safety control system. It can analyze internal state of storage cabinet to identify any hazardous situations and effectively control them. Such decentralized control system using sensor modules for internal environment of the cabinet storage and automated control algorithm based on administrator's log history can manage any hazardous situations by automated control of environment factors of inside a lab. It would allow users to deal with a hazard if it happens. Even better, it can prevent it to happen from the beginning.

• Journal of Preventive Medicine and Public Health
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• v.52 no.2
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• pp.140-144
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• 2019

Objectives: Investigating the survival of patients with cancer is vitally necessary for controlling the disease and for assessing treatment methods. This study aimed to compare various statistical models of survival and to determine the survival rate and its related factors among patients suffering from lung cancer. Methods: In this retrospective cohort, the cumulative survival rate, median survival time, and factors associated with the survival of lung cancer patients were estimated using Cox, Weibull, exponential, and Gompertz regression models. Kaplan-Meier tables and the log-rank test were also used to analyze the survival of patients in different subgroups. Results: Of 102 patients with lung cancer, 74.5% were male. During the follow-up period, 80.4% died. The incidence rate of death among patients was estimated as 3.9 (95% confidence [CI], 3.1 to 4.8) per 100 person-months. The 5-year survival rate for all patients, males, females, patients with non-small cell lung carcinoma (NSCLC), and patients with small cell lung carcinoma (SCLC) was 17%, 13%, 29%, 21%, and 0%, respectively. The median survival time for all patients, males, females, those with NSCLC, and those with SCLC was 12.7 months, 12.0 months, 16.0 months, 16.0 months, and 6.0 months, respectively. Multivariate analyses indicated that the hazard ratios (95% CIs) for male sex, age, and SCLC were 0.56 (0.33 to 0.93), 1.03 (1.01 to 1.05), and 2.91 (1.71 to 4.95), respectively. Conclusions: Our results showed that the exponential model was the most precise. This model identified age, sex, and type of cancer as factors that predicted survival in patients with lung cancer.

• Food Science of Animal Resources
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• v.38 no.6
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• pp.1237-1245
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• 2018

In this study, the contamination levels of hygienic indicators and foodborne pathogens in retail meat products were investigated in relation to the various market factors including processing temperature, processing area, and market type. Ground beef samples (n=80) were purchased from 40 meat markets and investigated for microbiological quality. Beefs processed below $20^{\circ}C$ had significantly lower numbers of total coliforms (TC) than these processed over $20^{\circ}C$ (2.01 vs. 2.79 log CFU/g; p<0.05). Interestingly, separation of processing area did not affect the contamination levels. Remarkably, the contamination levels of hygienic indicator differ among market types, indicating that not only processing condition but distribution structure that is directly related with storage period could affect the final microbiological loads of the meat products. In addition, the prevalences of Listeria monocytogenes (a psychrotroph), Enterococcus faecium, and Enterococcus faecalis were 7.5% (6/80), 10.0% (8/80), and 20.0% (16/80), respectively, which is irrelevant to market factors except meat products from wholesale markets where no L. monocytogenes were found among 30 samples. The results of this study indicate that the contamination level of hygiene indicator and foodborne pathogens in retail beef is more related with processing temperature and storage period than other environmental factors.

• The Korean Journal of Urological Oncology
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• v.16 no.3
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• pp.126-134
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• 2018

Purpose: The purpose of this study is to compare the radiation therapy (RT) and radical prostatectomy (RP) of high-risk or locally advanced prostate cancer (PC) patients after neoadjuvant hormonal therapy (NHT). Materials and Methods: This retrospective study evaluated patients underwent RT (42 patients) or RP (152 patients) after NHT at a single center during 2003-2014. Times to biochemical recurrence (BCR), pelvic local recurrence (PLR), metastasis, clinical painful symptom progression (CPSP), castration-resistant PC (CRPC), and overall survival were compared between the RT and RP groups, after adjustment for TN stage, using the Kaplan-Meier method and log-rank test. Results: Significant inter-group differences were observed for age, Gleason score, initial PSA, and clinical and pathological T stages (all p<0.05). During a median follow-up of 71.7 months, the overall incidences of BCR, PLR, metastasis, CPSP, CRPC, and death were 49.5%, 16.5%, 8.3%, 7.7%, 7.7%, and 17.5%, respectively. The median times to BCR were 100 months for RT and 36.2 months for RP (p=0.004), although the median times were not reached for the other outcomes (all p>0.05). The independent predictor of CPSP was RP (hazard ratio, 0.291; p=0.013). Conclusions: Despite significantly different baseline parameters, RP provided better CPSP-free survival than RT among patients with localized high-risk or locally advanced PC.

• Journal of Yeungnam Medical Science
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• v.38 no.1
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• pp.39-46
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• 2021

Background: To determine the benefit of pelvic floor muscle exercise (PFME) with visual biofeedback on promoting patient recovery from incontinence, we investigated variables associated with the early restoration of continence for patients who underwent robot-assisted radical prostatectomy (RARP). Methods: Of the 83 patients enrolled, 41 consecutive patients completed PFME (the exercise group), and the other 42 consecutive patients just before the PFME program commenced (the control group). The primary outcome was whether PFME engagement was associated with zero pad continence restoration within 3 months of surgery. Results: Continence restoration percentages (defined as zero pads used per day) at 1, 3, and 6 months after surgery were 49.4%, 77.1%, and 94.0%, respectively. The exercise group achieved significantly higher recovery rates at 1 month (p=0.037), 3 months (p<0.001), and 6 months (p=023). Cox regression analysis demonstrated that a lower Gleason score (<8; hazard ratio [HR], 2.167), lower prostate specific antigen (<20 ng/dL; HR, 2.909), and engagement in PFME (HR, 3.731) were independent predictors of early recovery from postprostatectomy incontinence. Stratification by age showed that those younger than 65 years did not benefit significantly from exercise (log-rank test, p=0.08), but that their elderly counterparts, aged 65-70 years (p=0.007) and >70 years old (p=0.002) benefited significantly. Conclusion: This study suggests that postoperative engagement in PFME with biofeedback speeds up the recovery of continence in elderly patients (≥65 years old) that undergo RARP.

• Journal of Gastric Cancer
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• v.21 no.2
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• pp.155-168
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• 2021

Purpose: Previous studies have demonstrated the usefulness of the controlling nutritional status (CONUT) score in nutritional assessment and survival prediction of patients with various malignancies. However, its value in advanced gastric cancer (GC) treated with neoadjuvant chemotherapy and curative gastrectomy remains unclear. Materials and Methods: The CONUT score at different time points (pretreatment, preoperative, and postoperative) of 272 patients with advanced GC were retrospectively calculated from August 2004 to October 2015. The χ² test or Mann-Whitney U test was used to estimate the relationships between the CONUT score and clinical characteristics as well as short-term outcomes, while the Cox proportional hazard model was used to estimate long-term outcomes. Survival curves were estimated by using the Kaplan-Meier method and log-rank test. Results: The proportion of moderate or severe malnutrition among all patients was not significantly changed from pretreatment (13.5%) to pre-operation (11.7%) but increased dramatically postoperatively (47.5%). The pretreatment CONUT-high score (≥4) was significantly associated with older age (P=0.010), deeper tumor invasion (P=0.025), and lower pathological complete response rate (CONUT-high vs. CONUT-low: 1.2% vs. 6.6%, P=0.107). Pretreatment CONUT-high score patients had worse progression-free survival (P=0.032) and overall survival (OS) (P=0.026). Adjusted for pathologic node status, the pretreatment CONUT-high score was strongly associated with worse OS in pathologic node-positive patients (P=0.039). Conclusions: The pretreatment CONUT score might be a straightforward index for immune-nutritional status assessment, while being a reliable prognostic indicator in patients with advanced GC receiving neoadjuvant chemotherapy and curative gastrectomy. Moreover, lower pretreatment CONUT scores might indicate better chemotherapy responses.

• Journal of Gastric Cancer
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• v.21 no.4
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• pp.335-351
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• 2021

Purpose: An underlying factor for the failure of several clinical trials of anti-epidermal growth factor receptor (EGFR) therapies is the lack of an effective method to identify patients who overexpress EGFR protein. The quantitative dot blot method (QDB) was used to measure EGFR protein levels objectively, absolutely, and quantitatively. Its feasibility was evaluated for the prognosis of overall survival (OS) of patients with gastric cancer. Materials and Methods: Slices of 2×5 ㎛ from formalin-fixed paraffin-embedded gastric cancer specimens were used to extract total tissue lysates for QDB measurement. Absolutely quantitated EGFR protein levels were used for the Kaplan-Meier OS analysis. Results: EGFR protein levels ranged from 0 to 772.6 pmol/g (n=246) for all gastric cancer patients. A poor correlation was observed between quantitated EGFR levels and immunohistochemistry scores with ρ=0.024 and P=0.717 in Spearman's correlation analysis. EGFR was identified as an independent negative prognostic biomarker for gastric cancer patients only through absolute quantitation, with a hazard ratio of 1.92 (95% confidence interval, 1.05-3.53; P=0.034) in multivariate Cox regression OS analysis. A cutoff of 208 pmol/g was proposed to stratify patients with a 3-year survival probability of 44% for patients with EGFR levels above the cutoff versus 68% for those below the cutoff based on Kaplan-Meier OS analysis (log rank test, P=0.002). Conclusions: A QDB-based assay was developed for gastric cancer specimens to measure EGFR protein levels absolutely, quantitatively, and objectively. This assay should facilitate clinical trials aimed at evaluation of anti-EGFR therapies retrospectively and prospectively for gastric cancer.