• Clinical Pain
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• v.16 no.1
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• pp.20-25
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• 2017

Objective: To find that the patients who conducted home self-exercise in conjunction with intra-articular corticosteroid injection will have better improvement in subacromial subdeltoid (SASD) bursitis symptoms than those who received only an injection. Method: A prospective, nonrandomized, comparison study was conducted in outpatient rehabilitation clinic in a tertiary university hospital. Patients diagnosed with SASD bursitis with physical examination and ultrasound evaluation were included and received ultrasound guided injection (UGI). Patients were divided into two groups according to the compliance of self-exercise: UGI-exercise group and UGI only group. Visual analog scale (VAS) was checked before, at 3 weeks, 3 months, and 6 months after the UGI. A patient's global impression of change (PGIC) survey was made at 3 months after the UGI. Results: A total of 82 patients with SASD bursitis were included. At 3 weeks after the injection, the mean VAS for the UGI-exercise group was 2.6 ± 1.7 and for UGI only group was 1.9 ± 1.3 (p=0.030). At 3 months after the injection, the mean VAS for the UGI-exercise group was 4.0 ± 1.3 and for UGI only group was 5.4 ± 1.4 (p<0.001). Conclusion: We concluded that home-based self-exercise of the shoulder provides an additional benefit for pain alleviation possibly with prolonging the effect of injection in SASD bursitis.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.4
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• pp.419-426
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• 2023

Objectives: This study aims to develop an Occupational Safety and Health (OSH) guide for the safe cleaning of contaminated machinery, equipment, and parts used in the electronics manufacturing process. Methods: A literature review, field investigations, and discussions were conducted. An initial draft of an OSH guide was developed and reviewed by experts with significant experience in maintenance work in the electronics manufacturing process in order to refine the guide. Results: Workers involved in cleaning processes with chemicals, solvents, and abrasive blasting can face exposure to a wide range of chemicals, abrasives, and noise. Identifying potential risks associated with each cleaning technique was an essential first step toward enhancing safety measures. The OSH guide comprises approximately eleven to twelve sections spanning 20-25 pages. It includes engineering and administrative protocols systematically organized to address the necessary actions before, during, and after cleaning tasks, depending on the technique. It is recommended that airline respirator masks be used in conjunction with an air purification system to ensure adherence to air quality standard "D" for atmosphere level. The use of an oil-free air compressor is advised, preferably a stationary model that does not rely on fuel sources like diesel. Conclusions: This OSH guide is designed to protect workers involved in maintenance activity in the electronics industry and aligns with global standards, such as those from the International Organization for Standardization (ISO) and Semiconductor Equipment and Material International, ensuring a higher level of safety and compliance.

• Korea Trade Review
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• v.45 no.2
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• pp.191-209
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• 2020

Project logistics is becoming increasingly important in overseas plant projects. Efficient logistics risk management is needed to reduce construction period and reduce costs. However, Korean construction firms bid unconditionally without sufficient experience and analysis on overseas plants contract, companies are gradually losing profitability on projects due to not considering profitability. Despite the significant effects on the profitability of Korean construction companies, and although these companies still continue to bid on overseas plant projects, policies to manage project logistics risks for safe transport and compliance with the contracted building schedule in the long term is still lacking. Hence, this study investigates the risk factors related to project logistics and to analyze the effect of project logistics risk on overseas plant business performance. We conducted a survey of project-related workers. The results of the analysis are as follows: First, among the logistics risk factors, overseas platform business people recognize operational risk and financial risk factors, which have a positive effect directly on overseas plant performance. Second, the ability to manage project logistics risks can have a significant impact on the success or failure of overseas plants. Finally, if logistics risk factors are managed on the basis of the research results confirmed through empirical analysis, it is possible to carry out more efficient and effective management of the project, which implies that this will have a positive effect on overseas plant business performance.

• The Korean Journal of Archival Studies
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• no.18
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• pp.139-178
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• 2008

The functional requirements standards for electronic records management systems which have been published recently describe the specifications very precisely including not only core functions of records management but also the function of system management and optional modules. The fact that these functional requirements standards seem to be similar to each other in terms of the content of functions described in the standards is linked to the global standardization trends in the practical area of electronic records. In addition, these functional requirements standards which have been built upon with collaboration of archivists from many national archives, IT specialists, consultants and records management applications vendors result in not only obtaining high quality but also establishing the condition that the standards could be the certificate criteria easily. Though there might be a lot of different ways and approaches to benchmark the functional requirements standards developed from advanced electronic records management practice, this paper is showing the possibility and meaningful business cases of gaining useful practical ideas learned from imaging electronic records management practices related to the functional requirements standards. The business cases are explored central functions of records management and the intellectual control of the records such as classification scheme or disposal schedules. The first example is related to the classification scheme. Should the records classification be fixed at same number of level? Should a record item be filed only at the last node of classification scheme? The second example addresses a precise disposition schedule which is able to impose the event-driven chronological retention period to records and which could be operated using a inheritance concept between the parent nodes and child nodes in classification scheme. The third example shows the usage of the function which holds or freeze and release the records required to keep as evidence to comply with compliance like e-Discovery or the risk management of organizations under the premise that the records management should be the basis for the legal compliance. The last case shows some cases for bulk batch operation required if the records manager can use the ERMS as their useful tool. It is needed that the records managers are able to understand and interpret the specifications of functional requirements standards for ERMS in the practical view point, and to review the standards and extract required specifications for upgrading their own ERMS. The National Archives of Korea should provide various stakeholders with a sound basis for them to implement effective and efficient electronic records management practices through expanding the usage scope of the functional requirements standard for ERMS and making the common understanding about its implications.

• Korean Journal of Ecology and Environment
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• v.45 no.3
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• pp.271-277
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• 2012

The present study was conducted to assess the suitability of domestic natural waters as a Daphnia magna culture medium. In order to assess survival rate and reproductive output, young female daphnids (parent animals), aged less than 24 hours at the start of the test and produced in the Elendt M4 medium, were exposed to Elendt M4 medium, de-chlorinated tap water, and natural mineral water for 21 days. D. magna cultured in Elendt M4 medium (reference medium) and natural mineral water met the criteria of OECD No. 211, Daphnia magna Reproduction Test Guidelines in terms of percent adult survival, first day of reproduction, and average young production. However, the mortalities of adult daphnids observed in de-chlorinated tap water were more than 20% in two reproduction tests for 21 days. Mortality was observed on exposure days 13, 15, and 18 in de-chlorinated water. The use of D. magna is recommended in water of hardness >80 mg $CaCO_3\;L^{-1}$. However, the hardness of de-chlorinated tap water used in the present study was 50~53 mg $CaCO_3\;L^{-1}$. Therefore, it is judged that the delayed mortalities observed in de-chlorinated tap water were caused by a rapid decreased in hardness when the medium was changed from Elendt M4 to de-chlorinated tap water. When D. magna is cultured using domestic natural waters (underground water, surface water, and de-chlorinated water), the quality-control (QC) data should be maintained through a standardization for health assessment method, toxicity test method using reference chemical, test intervals of reference toxicant toxicity test, and data treatment and interpretation. In the long term, national research programs are needed for the development of test species which are representative of domestic aquatic environmental conditions among indigenous daphnids.

• Journal of the Society of Naval Architects of Korea
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• v.30 no.3
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• pp.116-126
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• 1993

The finite element method(FEM) has been commonly used for structural dynamic analysis. However, the direct global application of FEM to large complex structures such as ships and offshore structures requires considerable computational efforts, and remarkably more in structural dynamic optimization problems. Adoption of the component-mode synthesis method is an efficient means to overcome the above difficulty. Among three classes of the component-mode synthesis method, the free-interface mode method is recognized to have the advantages of better computational efficiency and easier implementation of substructures' experimental results, but the disadvantage of lower accuracy in analytical results. In this paper, an advanced method to improve the accuracy in the application of the free-interface mode method for the vibration analysis of large complex structures is presented. In order to compensate the truncation effect of the higher modes of substructures in the synthesis process, both residual inertia and stiffness effects are taken into account and a frequency shifting technique is introduced in the formulation of the residual compliance of substructures. The introduction of the frequency shrift ins not only excludes cumbersome manipulation of singular matrices for semi-definite substructural systems but gives more accurate results around the specified shifting frequency. Numerical examples of typical structural models including a ship-like two dimensional finite element model show that the analysis results based on the presented method are well competitive in accuracy with those obtained by the direst global FEM analysis for the frequencies which are lower than the highest one employed in the synthesis with remarkably higher computational efficiency and that the presented method is more efficient and accurate than the fixed-interface mode method.

• Journal of Korea Port Economic Association
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• v.39 no.4
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• pp.243-254
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• 2023

This study investigates the factors contributing to price fluctuations in the shipscrapping market, the final stage in a vessel's life cycle. Shipping companies make decisions on ship dismantling based on factors such as declining freight rates, increasing vessel age leading to higher costs, or compliance with new environmental regulations. Utilizing the FMOLS (Fully Modified Ordinary Least Squares) and VECM (Vector Error Correction Model) methodologies, the research explores the long-term elasticities of factors influencing shipscrapping prices and examines short-term causal relationships. Using a time series dataset spanning from December 2015 to April 2023, covering a total of 90 months, the study focuses on the shipscrapping prices of Capesize vessels in India and Bangladesh, which constitute a significant portion of the shipbreaking market. The findings indicate that, in the long term, shipscrapping prices are closely related to global scrap prices, 20-year-old secondhand Capesize vessel prices, newbuilding prices, and exchange rates. In terms of short-term causal relationships, an increase in global scrap prices induces a rise in shipscrapping prices, while the remaining variables do not contribute to such increases. Specifically, an escalation in shipscrapping prices is associated with increased prices of 20-year-old secondhand vessels, newbuilding prices, and exchange rates. However, the other variables do not show a significant influence on short-term increases in shipscrapping prices.

• Journal of the Korea Concrete Institute
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• v.22 no.3
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• pp.381-388
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• 2010

In this study, characteristics of the seismic response of the non-earthquake resistant reinforced concrete (RC) frame were identified. The test building is designed to withstand only gravity loads and not in compliance with modern seismic codes. Smooth bars were utilized for the reinforcement. Members are provided with minimal amount of stirrups to withstand low levels of shear forces and the core concrete is virtually not confined. Columns are slender and more flexible than beams, and beam-column connections were built without stirrups. Through the modeling of an example RC frame, the feasibility of the fiber elementbased 3D nonlinear analysis method was investigated. Since the torsion is governed by the fundamental mode shape of the structure under dynamic loading, pushover analysis cannot predict torsional response accurately. Hence, dynamic response history analysis is a more appropriate analysis method to estimate the response of an asymmetric building. The latter method was shown to be accurate in representing global responses by the comparison of the analytical and experimental results. Analytical models without rigid links provided a good estimation of reduced stiffness and strength of the test structure due to bond-slip, by forming plastic hinges closer to the column ends. However, the absence of a proper model to represent the bond-slip poased the limitations on the current inelastic analysis schemes for the seismic analysis of buildings especially for those with round steel reinforcements. Thus, development of the appropriate bond-slip model is in need to achieve more accurate analysis.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.16 no.3
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• pp.233-244
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• 2006

Of many volatile organic detergents for metals, benzine(CAS No. 8030-30-6), of which the toxicity has not yet been proven, has been used as an alternative of the halide compounds in the consideration of toxic effects, global warming and the destruction of ozone layer. In order to evaluate the effects of the benzine on human body by investigating the subchronic inhalation toxicity, to obtain the basic data for establishing the criteria of exposure in working environments and to classify the hazardousness in compliance with the Industrial Safety and Health Act by evaluating the hazardousness, repeated inhalation exposure test was carried with SD rats. The rats were grouped by 10 females and males each. The repetitive inhalation exposures were carried out at 4 levels of concentration of 0 ppm, 60 ppm, 300 ppm, and 1,500 ppm, for 6 hours a day, 5 days a week, for 13 weeks. The results are described hereunder. 1. No death of the animals of the exposed and controlled groups in the test period. Not any specific clinical symptoms, change in feed intake quantity, abnormality in eye test, or change in activity were observed. 2. In the 300 ppm and 1,500 ppm groups, weight reduction in the female groups and weight increase of liver and kidney in the male groups compared with control group were observed with statistical significance(p<0.05). 3. In the blood test, the HCT increased in the male 300 ppm group and the number of hematocyte increased, MCV and MCH decreased in the male 1,500 ppm group. In the female 1,500 ppm group, the HB decreased and the distribution width of the hematocyte particle size increased. In the blood biochemistry test, the TP in the male 1,500 ppm group and the LDH in the female 1,500 ppm group were increased with statistical significance(p<0.05). 4. Under the test conditions of the present study with SD rats, the NOEL was evaluated to be from 60 ppm to 300 ppm for both male and female groups. By extrapolation, the NOEL for human who work 8 hours a day was evaluated to be from 128 ppm to 640 ppm 5. Since the NOEL evaluated in this study do not exceed 60ppm(0.184 mg/L) the test material does not belong to the classification of the hazardous substance "NOEL${\leq}$0.5mg/L/6hr/90day(rat), for continuous inhalation of 6hours a day for 90 days" nor to the basic hazardous chemical substance class 1(0.2 mg/L/6hr/90day(rat) defined by the GHS which is a criteria of classification and identification of chemical compounds. However, considering the boiling point($30-204^{\circ}C$), flashing point($-40^{\circ}C$), vapor pressure(40 mmHg), and the inflammable range(1.0 - 6.0 %), sufficient care should be taken for handling in the safety aspects including fire or explosion.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.1
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• pp.1-8
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• 2014

Using the level set and the meshfree methods, we develop a topological shape optimization method applied to linear elasticity problems. Design gradients are computed using an efficient adjoint design sensitivity analysis(DSA) method. The boundaries are represented by an implicit moving boundary(IMB) embedded in the level set function obtainable from the "Hamilton-Jacobi type" equation with the "Up-wind scheme". Then, using the implicit function, explicit boundaries are generated to obtain the response and sensitivity of the structures. Global nodal shape function derived on a basis of the reproducing kernel(RK) method is employed to discretize the displacement field in the governing continuum equation. Thus, the material points can be located everywhere in the continuum domain, which enables to generate the explicit boundaries and leads to a precise design result. The developed method defines a Lagrangian functional for the constrained optimization. It minimizes the compliance, satisfying the constraint of allowable volume through the variations of boundary. During the optimization, the velocity to integrate the Hamilton-Jacobi equation is obtained from the optimality condition for the Lagrangian functional. Compared with the conventional shape optimization method, the developed one can easily represent the topological shape variations.