• Journal of the Korean Society of Safety
• /
• v.25 no.6
• /
• pp.34-39
• /
• 2010

The purpose of this study is to suggest objective evaluation model as a plan to utilize as opportunity in establishing judgment standard of mutual inspection criteria and to upgrade inspection ability by reviewing and analyzing level of danger and importance in advance based on inspection results of inspection institutions regarding tower cranes used in construction fields. Tower crane is a mechanical device transporting construction supplies and heavy materials to places over 20~150M high from the ground for the period ranging from a short time of 2~3 months to two years after being installed in construction sites in vicinity of buildings or structures and is an important facility indispensable for construction sites. However, since use period after installation is short and professional technical ability of technicians working on-site about of tower crane is poor, systematic and quantitative safety management is not carried out As a part of researches on procedure of RBI(Risk Based Inspection) possible to apply to Knowledge Based System based on knowledge and experiences of experts as well as to tower cranes for solving these problems, quantitative RPN(Risk Priority Number) was applied to RPN utilizing technique of FMEA(Failure Mode and Effect Analyses). When general RBI 80/20 Rule was applied parts with high level of risks were found out as wire rope, hoist up/down safety device, reduction gear, and etc. However, since there are still many insufficient parts as risk analyses of tower crane were not established, it is necessary for experts with sufficient experiences and knowledge to supplement active RBI techniques and continuous researches on tower cranes by sharing and setting up data base of important information with this study as a starting point.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.18 no.3 s.39
• /
• pp.99-113
• /
• 1990

The purpose of this study was to prepare some more up-dated and advanced curriculum in Landscape Architecture in Junior College education to bring up a leading professional who can meet the changing social needs. To achieve this goal, the data about the actual employment status of graduates, current relevant systems and legistations, the questionnaires of Landscape companies, graduates and undergraduates, and the current relevant curriculum of domain 6 junior colleges and Japanese relevant curriculum was gathered and analyzed The results are as follows ; 1. Currently the majority of the graduates are employed in Construction field, but the employment trend of graduates shows diversification and subdividing as following 5 fields, that is Construction, Design, Maintenance, Administration and Indoor Landscaping. 2. It is essential to bring up a Landscape Technician who has a Landscape Certificate of qualifications(esp. 2nd class). 3. Lately, the actual Practice came to be one item of the qualifying examination, so the subjects of Landscape Design, Landscape Construction and Landscape Estimation Should be emphasized, Accordingly, current curriculum should be revised. 4. Currant curriculum model(1979) made by the Ministry of Education doesn't play a real and adequate role and should be up-dated in view of the current curriculum of domain 6 junior colleges has no regular standards. In preparation for new standardized curriculum model, following criterior could be suggested, that is, ratio of the Major Required Subjects vs. The Major Optional Subjects would be 50 : 50, and the Major Optional Subject would be 48 credits which is 150% of the Required Credits(32 credits) 5. The subjects such as Basic Agriculture, Afforestation, Nature Conservation, Sketch, Civil Engineering, Landscape Seminar and Modelling Practice would be deleted in the curriculum model established in 1983. 6. The subjects such as Perspective Practice, Indoor Landscaping, Landscape Legislation and Landscape Design( III ) could be newly opened to meet the social needs, to prepare for the qualifying examination and to serve well in the employment fields. 7. The subjects of Surveying ( I ) & ( II ) would be unified into one Subject as Surveying, and some in view of the average situation of 6 junior colleges. 8. It is urgent to open some subject related to computer. At first, An Introduction to Computer could be recommended in the cultural studies course and Landscape Computer Technique as the Major Optional Subjects.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2015.10a
• /
• pp.458-461
• /
• 2015

In this paper 2 types of voltage references and a current reference suitable for low-voltage, low-power circuits are proposed and designed with $0.35{\mu}m\;CMOS$ process. MOS transistors operating in weak inversion and bulk-driven technique are utilized to achieve low-voltage and low-power features. The first voltage reference consumes 1.43uA from a supply voltage of 1.2V while it has a reference voltage of 585mV and a TC(Temperature Coefficient) of $6ppm/^{\circ}C$. The second voltage reference consumes 48pW from a supply voltage of 0.3V while having a reference voltage of 172mV and a TC of $26ppm/^{\circ}C$. The current reference consumes 246nA from a supply voltage of 0.75V with a reference current of 32.6nA and a TC of $262ppm/^{\circ}C$. The performances of the designed references have been verified through simulations.

• Journal of the Korean Institute of Gas
• /
• v.18 no.4
• /
• pp.86-94
• /
• 2014

To develop a Root Cause Analysis Map which determines the cause of the accident in chemical laboratory, The Root Cause Analysis(RCA) Map for the laboratory areas was sketched from Phase 1 of the accident element to Phase 3 of the accident element, based on the RCA Map which is applied in the petrochemical industry. On the basis of laboratory RCA Map which was classified by using such method. The root causes of the 211 accident cases in laboratories were classified from Phase 4 to Phase 5 by the Cause Factor Charting technique and The cause of the accident data were inputted to EXCEL program. After that, The causes of the accident data were sorted and classified by type and each step. So 'Approximate Primary RCA Map Draft' was written. In addition, it was reaffirmed whether the root causes of 211 accidents of laboratory were appropriate to 'Primary RCA Map Draft'. By complementing the cause which was expected to cause future accidents, the RCA Map for chemical laboratories was developed. Based on 'RCA Map' proposed in this study, the causes of accidents were analysed management systems 35%, monitoring 12.2%, Human Factor Eng. 15.1% and education training 12.1% by the size of the frequency from Phase 1 to Phase 5.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2018.10a
• /
• pp.373-376
• /
• 2018

Traditional paprika smart farm systems are often harmful to paprika growth because they are set to follow the values of several sensors to the reference value, so the system is often unable to make optimal judgement. Using decision tree techniques, the expert system for the paprika smart farm is designed to create a control system with a decision-making structure similar to that of farmers using data generated by factors that depend on their surroundings. With the current smart farm control system, it is essential for farmers to intervene in the surrounding environment because it is designed to follow sensor values to the reference values set by the farmer. To solve this problem even slightly, it is going to obtain environmental data and design controllers that apply decision tree method. The expert system is established for complex control by selecting the most influential environmental factors before controlling the paprika smart farm equipment, including criteria for selecting decisions by farmers. The study predicts that each environmental element will be a standard when creating smart farms for professionals because of the interrelationships of data, and more surrounding environmental factors affecting growth.

• Korean Chemical Engineering Research
• /
• v.50 no.2
• /
• pp.353-357
• /
• 2012

The new qualitative and quantitative analytical method for hydrocarbon compounds in DME-LPG blending fuel, mixing dimethyl ether (DME) with liquefied petroleum gas (LPG), by using gas chromatography (GC) was investigated. It is difficult to analyze all components of DME-LPG blending fuel by using single column in GC due to consisting of the non-polar LPG and the polar DME which is oxygen-containing compound. Therefore, it has been introduced the Deans switching system, which are useful for analyzing mixtures of a very different nature and/or target analytes in very complex matrix. This technique is to control the pressure between two columns and to selectively change the path of effluent flows to either one of two columns. As a result, we found that DME and LPG can be completely separated at the different columns and the determination of all hydrocarbon compounds in DME-LPG blending fuel can be achieved to this method qualitatively and quantitatively during the operation of one injection. In addition, this method can be applied to the determination of trace components of by-product, such as methanol, methyl formate and ethyl methyl ether, which will be derived from DME synthesis process.

• KIPS Transactions on Software and Data Engineering
• /
• v.4 no.12
• /
• pp.549-560
• /
• 2015

There is a wide variety of data quality attributes such as the ones proposed by the ISO/IEC organization and also by many other domestic and international institutions. However, it takes considerable time and costs to apply those criteria and guidelines to real environment. Therefore, it needs to define data quality evaluation attributes which are easily applicable and are not influenced by organizational environment limitations. The purpose of this paper is to derive data quality attributes and order of their priorities based on customer requirements for managing the process systematically and evaluating the data quantitatively. This study identifies the customer cognitive constructs of data quality attributes using the RGT(Repertory Grid Technique) based on a Korean quality standard model (DQC-M). Also the correlation analysis on the identified constructs is conducted, and the evaluation attributes is prioritized and ranked using the AHP. As the results of this paper, the consistent system, the accurate data, the efficient environment, the flexible management, and the continuous improvement are derived at the first level of the data quality evaluation attributes. Also, Control Compliance(13%), Regulatory Compliance(10%), Requirement Completeness(9.6%), Accuracy(8.4%), and Traceability(6.8%) are ranked on the top 5 of the 19 attributes in the second level.

• KIPS Transactions on Software and Data Engineering
• /
• v.4 no.12
• /
• pp.543-548
• /
• 2015

Recently top-k query processing has been extremely important along with the explosion of data produced by a variety of applications. Top-k queries return the best k results ordered by a user-provided monotone scoring function. As cloud computing service has been getting more popular than ever, a hot attention has been paid to cloud-based data outsourcing in which clients' data are stored and managed by the cloud. The cloud-based data outsourcing, though, exposes a critical secuity concern of sensitive data, resulting in the misuse of unauthorized users. Hence it is essential to encrypt sensitive data before outsourcing the data to the cloud. However, there has been little attention to efficient top-k processing on the encrypted cloud data. In this paper we propose a novel top-k processing algorithm that can efficiently process a large amount of encrypted data in the cloud. The main idea of the algorithm is to prune unpromising intermediate results at the early phase without decrypting the encrypted data by leveraging an order-preserving encrypted technique. Experiment results show that the proposed top-k processing algorithm significantly reduces the overhead of client systems from 10X to 10000X.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.19 no.2
• /
• pp.143-159
• /
• 2017

A probabilistic fragility assessment procedure is developed in this paper to predict risks of damage arising from seismic loading to the two-cell RC box tunnel. Especially, the paper focuses on establishing a simplified methodology to derive fragility curves which are an indispensable ingredient of seismic fragility assessment. In consideration of soil-structure interaction (SSI) effect, the ground response acceleration method for buried structure (GRAMBS) is used in the proposed approach to estimate the dynamic response behavior of the structures. In addition, the damage states of tunnels are identified by conducting the pushover analyses and Latin Hypercube sampling (LHS) technique is employed to consider the uncertainties associated with design variables. To illustrate the concepts described, a numerical analysis is conducted and fragility curves are developed for a large set of artificially generated ground motions satisfying a design spectrum. The seismic fragility curves are represented by two-parameter lognormal distribution function and its two parameters, namely the median and log-standard deviation, are estimated using the maximum likelihood estimates (MLE) method.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.40 no.7
• /
• pp.441-448
• /
• 2016

The thrust force created by a propeller depends on the incoming flow velocity and the rotational velocity of the propeller. The performance of the propeller can be described by dimensionless variables, advanced ratio, thrust coefficient, and power coefficient. This study included the application of the immersed boundary lattice Boltzmann method (IBLBM) with the stereo lithography (STL) file of the rotating object for performance analysis. The immersed boundary method included the addition of the external force term to the LB equation defined by the velocity difference between the lattice points of the propeller and the grid points in the domain. The flow by rotating a 4-blade propeller was simulated with various Reynolds numbers (Re) (including 100, 500 and 1000), with advanced ratios in the range of 0.2~1.4 to verify the suggested method. The typical tendency of the thrust efficiency of the propeller was obtained from the simulation results of different advanced ratios. It was also necessary to keep the maximum mesh size ratio of the propeller surface to a grid size below 3. Additionally, a sufficient length of the downstream region in the domain was maintained to ensure the numerical stability of the higher Re and advanced ratio flow.