• Korean Journal of Construction Engineering and Management
• /
• v.4 no.1 s.13
• /
• pp.106-113
• /
• 2003

In this study, The matrix method was used with common category concept according to the construction project control system. For the purpose of systematic resource management planning, it should be established on accomplished EVM data for clearing the ordering point according to the attribute procurement analysis. Resource management was presented by connecting the material requirement calculation method and the attribute of procurement method based on the EVM, suggested through analyzing process-data modeling using integrated schedule, cost and material.

• Korean Journal of Medicinal Crop Science
• /
• v.20 no.6
• /
• pp.434-439
• /
• 2012

This study was conducted to determine the contents of heavy metal in commercial herbal medicines. The monitoring of lead, arsenic, cadmium and mercury was carried out on 100 samples with 10 kinds of herbal medicines. The contents of heavy metal were measured by inductively coupled plasma atomic emission spectrometry (ICP-AES) and mercury analyzer. The mean values of heavy metal contents for herbal medicines were Pb 1.87 mg/kg, As 0.39 mg/kg, Cd 0.26 mg/kg and Hg 0.021 mg/kg. Of the total samples, 19 samples (19%, 4 types) were violated the KFDA regulatory guidance of heavy metal in herbal medicines (9 samples on Pb, 10 samples on Cd). Among these 19 unsuitable samples, 16 samples were domestic and 3 samples were imported. Therefore, we need continuously monitoring to ensure confidence and safety for these herbal medicines.

• Journal of Advanced Navigation Technology
• /
• v.23 no.5
• /
• pp.466-472
• /
• 2019

The purpose of this study is to examine the problems of disaster management resources needed for disaster occurrence, to find ways to improve them, and to utilize them in the future. For this research, theoretical background was established through previous research data on disaster management resources. Disaster management resources prescribed in the Basic Act on Disaster and Safety Management, Classification of Disaster Management Resources and System Use, and Joint Utilization Standards of Disaster Management Resources were analyzed to identify problems and to suggest improvements. As a result of the research, clarity on disaster management resources was secured through literature research and analysis of laws and regulations. By suggesting ways to utilize the manpower and material resources designated by the Emergency Preparedness Resource Management Act in the event of various disasters, it was confirmed that the disaster management resources could be utilized in the right place for various disaster situations.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• autumn
• /
• pp.341-344
• /
• 2003

There are many problems in management of high-rise building construction performed in downtown area due to limited spaces and equipments for increasing kinds and quantities of material. By these restrictions, problems such as increase of construction cost. delay of construction period, decrease of productivity, occurrence of accident are caused. Recently, studies on JIT concept have focused on construction materials as a solution for the problems. But, studies about finishing material are insufficient yet. Accordingly, this study suggests flowing of current material management, JIT management effect, and development direction of lifting-up and procurement system with Low-emissivity double Glazing, among of main finishing materials.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.7 no.2
• /
• pp.110-119
• /
• 2007

A new two-dimensional analytical model for dual-material double-gate fully-depleted SOI MOSFET with Pearson-IV type Doping Distribution is presented. An investigation of electrical MOSFET parameters i.e. drain current, transconductance, channel resistance and device capacitance in DM DG FD SOI MOSFET is carried out with Pearson-IV type doping distribution as it is essential to establish proper profiles to get the optimum performance of the device. These parameters are categorically derived keeping view of potential at the center (${\phi}_c$) of the double gate SOI MOSFET as it is more sensitive than the potential at the surface (${\phi}_s$). The proposed structure is such that the work function of the gate material (both sides) near the source is higher than the one near the drain. This work demonstrates the benefits of high performance proposed structure over their single material gate counterparts. The results predicted by the model are compared with those obtained by 2D device simulator ATLAS to verify the accuracy of the proposed model.

• Journal of the Korean Society of Visualization
• /
• v.21 no.2
• /
• pp.34-45
• /
• 2023

When lithium-ion batteries operate out of the proper temperature range, their performance can be significantly degraded and safety issues such as thermal runaway can occur. Therefore, battery thermal management systems are widely researched to maintain the temperature of Li-ion battery cells within the proper temperature range during the charging and discharging process. This study investigates the cooling performance and isothermal maintenance of cooling materials by measuring the surface temperature of a battery cell with or without cooling materials, such as silicone oil, thermal adhesive, and phase change materials during discharge process of battery by the experimental and numerical analysis. As a result of the experiment, the battery pack filled with phase change material showed a temperature reduction of 47.4 ℃ compared to the case of natural convection. It proves the advanced utility of the cooling unit using phase change material that is suitable for use in battery thermal management systems.

• Journal of the Korea Convergence Society
• /
• v.9 no.7
• /
• pp.47-53
• /
• 2018

The actual condition of safety management and problems for hazardous material facilities in national industrial complex are investigated and analyzed in fields of hazardous material facilities safety, fire fighting equipment safety, building safety, space safety. In most cases, the failure to comply with legal requirements and the maintenance of fire safety have been pointed out. As a result, the total number of problems identified was 466 and problems in the field of hazardous material facilities safety have been pointed out the most. Also, it was analyzed that the number of problems identified in the manufacturing facilities and general handling centers among the hazardous materials facilities was the highest. Therefore, it will contribute to strengthening the safety management capability of the national industrial complex in the future by suggesting the convergence direction of the safety diagnosis system and the systematic introduction of the precise safety diagnosis.

• Journal of Applied Biological Chemistry
• /
• v.49 no.3
• /
• pp.101-105
• /
• 2006

Degradation of the herbicide butachlor was investigated using laboratory-synthesized zerovalent iron ($Fe^0$). The synthesized zerovalent iron was determined to be nanoscale powder by scanning electron microscopic analysis. To investigate degradation of butachlor using the synthesized nanoscale zerovalent iron, time-course batch experiments were conducted by treating the solution of butachlor formulation with the iron. More than 90% degradation of butachlor was observed by iron treatment within 24 h. The synthesized nanoscale zerovalent iron showed an increase in particle aggregation in the batch tests. Green rust formation and a pH drop in solutions were observed, suggesting that the oxidation of the iron occurred. When the iron was extracted with dichloromethane, a negligible concentration was found in the extract, suggesting that butachlor did not bind to the iron particles. GC/MS analysis detected the dechlorinated product as a major degradation product of butachlor in the solutions. The data indicate that laboratory-synthesized zerovalent iron functioned as a reductant to remove electron-withdrawing chlorine, giving the dechlorinated product.

• Journal of Construction Engineering and Project Management
• /
• v.7 no.3
• /
• pp.15-25
• /
• 2017

The existence of material price volatility in construction projects puts forward substantial risks for all parties involved. Depending on the parties involved in the project, type of contracts, and state of the market various risk management strategies are practiced by contracting parties to manage project risks related to price volatility. Unfortunately, in many cases companies fail to select an adequate approach to better manage volatilities of material prices due to the lack of a decision support system to aid in the selection of an appropriate strategy based on the project characteristics. The aim of this study is to identify critical project factors and align them to documented strategies to manage price volatility based on an extensive literature review and industry interviews. This study found Integrated Project Delivery (IPD) as the ideal strategy with respect to project duration; quantitative risk management methods with respect to the cost; and Price Adjustment Clauses (PAC) with respect to the risk allocation, as the top price volatility management strategies.

• Journal of the Korean Society of Radiology
• /
• v.14 no.3
• /
• pp.193-201
• /
• 2020

The purpose of this study is to evaluate the photon characteristics according to the material and thickness of the electrons incidented through a linear accelerator. The computer simulation design is a linear accelerator target consisting of a 2 mm thick tungsten single material and a 1.8 mm and 2.3 mm thick tungsten and copper composite material. In the research method, First, the behavior of primary particles in the target was evaluated by electron fluence and electron energy deposition. Second, photons occurring within the target were evaluated by photon fluence. Finally, the photon angle-energy distribution at a distance of 1 m from the target was evaluated by photon fluence. As a result, first, electrons, which are primary particles, were not released out of the target for electron fluence and energy deposition in the target of a single material and a composite material. Then, electrons were linearly attenuated negatively according to the target thickness. Second, it was found that the composite material target had a higher photon generation than the single material target. This confirmed that the material composition and thickness influences photon production. Finally, photon fluence according to the angular distribution required for shielding analysis was calculated. These results confirmed that the photon generation rate differed depending on the material and thickness of the linear accelerator target. Therefore, this study is necessary for designing and operating a linear accelerator use facility for container security screening that is being introduced in the country. In addition, it is thought that it can be used as basic data for radiation protection.