• Safety and Health at Work
• /
• v.8 no.2
• /
• pp.206-211
• /
• 2017

Background: Self-reported low back pain (LBP) has been evaluated in relation to material handling lifting tasks, but little research has focused on relating quantifiable stressors to LBP at the individual level. The National Institute for Occupational Safety and Health (NIOSH) Composite Lifting Index (CLI) has been used to quantify stressors for lifting tasks. A chemical exposure can be readily used as an exposure metric or stressor for chemical risk assessment (RA). Defining and quantifying lifting nonchemical stressors and related adverse responses is more difficult. Stressor-response models appropriate for CLI and LBP associations do not easily fit in common chemical RA modeling techniques (e.g., Benchmark Dose methods), so different approaches were tried. Methods: This work used prospective data from 138 manufacturing workers to consider the linkage of the occupational stressor of material lifting to LBP. The final model used a Bayesian random threshold approach to estimate the probability of an increase in LBP as a threshold step function. Results: Using maximal and mean CLI values, a significant increase in the probability of LBP for values above 1.5 was found. Conclusion: A risk of LBP associated with CLI values > 1.5 existed in this worker population. The relevance for other populations requires further study.

• New & Renewable Energy
• /
• v.5 no.4
• /
• pp.21-27
• /
• 2009

Potential yield of micro wind turbine on the roof of urban high rise buildings is estimated. Urban wind profile is modeled as logarithmic profile above the mean building height with roughness length 0.8, displacement 7.5 m. Mean wind velocity from the meteorological agency data at the hight of 50m is used. Wind velocity changes are simulated on the rectangular roof of 26, 45, 53 degree pitch and the circular roof by computational fluid dynamics and RNG k-$\varepsilon$ turbulence models. Wind velocity increased approximately by a factor of the order of 270 % on the 26 degree pitched roof. In the 100 m and 200 m high buildings, wind enhancement is greater at the front side than at the center of the building. In the building arrangement model wind velocity changes abruptly and it becomes wind gusts. When commercial wind turbines are installed on the building roof, average power and annual power generation enhanced by 3~4 times than normal wind velocity at 50m and 6 kw wind turbine can generate 1053 kwh per month on the 26 degree pitched roof at 50m height and sufficiently supply electrical power with 15 household for common electrical use and food waste disposer. However, power output will vary significantly by the wind conditions in the order of $\pm$ 20 %.

• The KIPS Transactions:PartD
• /
• v.12D no.6 s.102
• /
• pp.857-862
• /
• 2005

MND(Ministry of National Defense) has developed MND AF(Ministry of National Defense Architecture Framework) and CADM(Core Architecture Data Model to guarantee interoperability among defense information systems. But, it is very difficult to manage architecture product documented through MND AF and CADM. So, there Is necessity for development of modeling tool and repository system which can develop architecture products and manage architecture product informations in common repository In this paper, we developed architecture product management system which supports development and management of meta model and architecture product of MND AF and CADM. Through architecture product management system architect of each agency can construct architecture product in a more effective and efficient way with modeling method and a user can search and refer useful architecture product informations using query function. Also, architecture product management system provides the basis for system integration and interoperability with integration, analysis and comparison of architecture product.

• Journal of the Korean Society for Library and Information Science
• /
• v.51 no.3
• /
• pp.163-188
• /
• 2017

This study aims to propose disaster safety information service model based on LOD for effective management and dissemination of the information. To achieve the aim of this study, current state of disaster safety information was analyzed through online search and face-to-face interviews, and then the information was divided into 6 types. Finally, this study proposed specific process of building disaster safety information LOD service with considerations reflecting the information characteristics. The process for building LOD was based on Guidelines for Building Linked Data written by National Information Society Agency. Especially, ontology concept model was defined by using standard lexical resources and modeling tools based on 6 types of disaster safety information, and classes and properties were proposed. The results of this study will make disaster safety information more useful for common people.

• Journal of Ocean Engineering and Technology
• /
• v.28 no.6
• /
• pp.552-559
• /
• 2014

In general, the number of underwater transient signals is very limited for research on automatic recognition. Data-dependent feature extraction is one of the most effective methods in this case. Therefore, we suggest WPCC (Wavelet packet ceptsral coefficient) as a feature extraction method. A wavelet packet best tree for each data set is formed using an entropy-based cost function. Then, every terminal node of the best trees is counted to build a common wavelet best tree. It corresponds to flexible and non-uniform filter bank reflecting characteristics for the data set. A GMM (Gaussian mixture model) is used to classify five classes of underwater transient data sets. The error rate of the WPCC is compared using MFCC (Mel-frequency ceptsral coefficients). The error rates of WPCC-db20, db40, and MFCC are 0.4%, 0%, and 0.4%, respectively, when the training data consist of six out of the nine pieces of data in each class. However, WPCC-db20 and db40 show rates of 2.98% and 1.20%, respectively, while MFCC shows a rate of 7.14% when the training data consists of only three pieces. This shows that WPCC is less sensitive to the number of training data pieces than MFCC. Thus, it could be a more appropriate method for underwater transient recognition. These results may be helpful to develop an automatic recognition system for an underwater transient signal.

• International Commerce and Information Review
• /
• v.15 no.2
• /
• pp.71-82
• /
• 2013

The automotive supply chain is increasingly complex as automakers seek more profitable solutions with global out-sourcing and manufacturing strategies. In the automotive industry, using returnable plastic containers (RPCs) is very common for domestic operations, but for internationally, it has not been considered by many companies because of issues such as overall distance and difficulty of control. The results of this simulation can help to analyze the interactive and coherent behavior of packaging and supply chain systems. The data obtained from the model can be applied to make substantial decisions for choosing the most profitable packaging types, at the same time as it can lead to designing an optimum supply chain for RPCs used in international supply chains.

• Safety and Health at Work
• /
• v.13 no.2
• /
• pp.240-247
• /
• 2022

Background: Although insomnia and constipation are highly prevalent worldwide, studies examining a possible association between them are lacking. We examined the relationship between insomnia and constipation in shift workers who have a high prevalence of insomnia and other diseases. Methods: This study had a multicenter cross-sectional design and conducted using health examination data including self-reported questionnaires. In total, 12,879 and 4,650 shift workers were enrolled in Severance Hospital and Wonju Severance Hospital, respectively, during 2015-2017. Multivariate logistic regression models and subgroup analysis were performed in each center with the same protocol, using a common data model. Results: The mean age of the total population was 44.35 (standard deviation = 8.75); the proportion of males was 56.9%. Female sex, being underweight and non-smoker were strongly associated with an increased risk of constipation symptom (p < 0.001). Pooled odds ratios (ORs) were calculated using ORs of both centers with weights; there was a significant dose-response relationship (sub-threshold 1.76 [95% confidence interval [CI] 1.62-1.91]; moderate 2.28 [95% CI 2.01-2.60]; severe 4.15 [95% CI 3.18-5.41] in the final model, p for trend < 0.001). Subgroup analysis performed by stratifying sex and pooled ORs showed a similar trend to that of the entire group. Conclusion: We observed a strong correlation between insomnia and constipation in this population. Our findings may help in formulating guidelines and policies to improve quality of life in shift workers through the management of sleep quality and proper bowel function. This study is the first to report this relationship among people working in shifts.

• Journal of Information Technology Services
• /
• v.21 no.4
• /
• pp.63-74
• /
• 2022

Globally researchers at medical institutions are actively sharing COHORT data of patients to develop vaccines and treatments to overcome the COVID-19 crisis. OMOP-CDM, a common data model that efficiently shares medical data research independently operated by individual medical institutions has patient personal information (e.g. PII, PHI). Although PII and PHI are managed and shared indistinguishably through de-identification or anonymization in medical institutions they could not be guaranteed at 100% by complete de-identification and anonymization. For this reason the security of the OMOP-CDM database is important but there is no detailed and specific OMOP-CDM security inspection tool so risk mitigation measures are being taken with a general security inspection tool. This study intends to study and present a model for implementing a tool to check the security vulnerability of OMOP-CDM by analyzing the security guidelines for the US database and security controls of the personal information protection of the NIST. Additionally it intends to verify the implementation feasibility by real field demonstration in an actual 3 hospitals environment. As a result of checking the security status of the test server and the CDM database of the three hospitals in operation, most of the database audit and encryption functions were found to be insufficient. Based on these inspection results it was applied to the optimization study of the complex and time-consuming CDM CSF developed in the "Development of Security Framework Required for CDM-based Distributed Research" task of the Korea Health Industry Promotion Agency. According to several recent newspaper articles, Ramsomware attacks on financially large hospitals are intensifying. Organizations that are currently operating or will operate CDM databases need to install database audits(proofing) and encryption (data protection) that are not provided by the OMOP-CDM database template to prevent attackers from compromising.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.25 no.1
• /
• pp.9-22
• /
• 2022

A fighter performing a reconnaissance mission is equipped with a pod that drives optical/infrared sensors for acquiring and identifying target information on the lower part of the fuselage. Due to the nature of the reconnaissance mission, the fighter performs high speed evasive maneuvers, and the resulting load should be considered importantly for the development of the pod. This paper concerns a numerical investigation into the inertial and aerodynamic loads of the airborne pod of high performance aircrafts. For the aerodynamic load analysis, the pylon and pod shapes are added to the fighter 3D model, and the commercial software was used for static and dynamic analysis. Considering the practical mission conditions, the common/extreme conditions were established respectively in the static and dynamic situations of pods and the driving torque could be tripled under dynamic conditions. In the analysis of inertia load, a 3-DOF model considering roll and turning maneuvers was derived by the Lagrangian method, and then the numerical integration method was applied to the analysis. As a results, it was conformed that the inertia load was generally induced at a low level compared to the aerodynamic load, but depending on the unbalance mass condition of the pod, the inertia load cannot be negligible.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.6
• /
• pp.178-186
• /
• 2020

In the domain of Korean weapon system development, issues about software reliability have become crucial factors when developing a weapon system. There is a process required for weapon system software development and management that includes certain activities required to improve the reliability of software. However, these activities are biased toward static and dynamic analyses of source code and do not include activities necessarily required by the international standard. IEEE std. 1633-2016 defines a process for software reliability engineering and describes software reliability estimation as an essential activity in the process. Software reliability estimation means that collecting defective data during the test and estimating software reliability by using the statistical model. Based on the estimated model, developers could estimate the failure rate and make comparisons with the objective failure rate to determine termination of the test. In this study, we collected defective data and applied reliability estimation models to analyze software reliability in the development of a weapon system. To achieve objective software reliability, we continuously tested our software and quantitatively calculated software reliability. Through the research, we hope that efforts to include activities described by the international standard will be carried out in the domain of Korean weapon system development.