• Membrane and Water Treatment
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• v.6 no.4
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• pp.277-292
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• 2015

The extraction of lactic acid by an emulsion liquid membrane (ELM), in batch and continuous mode, has been reported. On the basis of preliminary experiments, the optimum composition of the organic phase (membrane) is determined. When the SPan 80 is used as surfactant, the emulsion breakage exceeds 50%, but only 10% is obtained when the ECA4360 is used. The effects of surfactant, carrier and solute concentrations, phase volume ratio, and stirring speed on the extraction yield were examined and optimized. Surfactant, carrier and diluent used were ECA4360, trilaurylamine (TLA) and dodecane, respectively; 2-ethylhexane-1,3-diol (EHD) is used as a co-surfactant. Under optimal conditions, emulsion breaking is very low and the swelling is kept at its lowest level. Under the pH conditions of fermentation medium, the extraction yield is lower. A mixer-settler continuous system was used for testing these conditions. The residence time, the number of extraction stages and the stability of the emulsion were studied and optimized. The extraction yield obtained exceeds 90%.

• Journal of the Korean Statistical Society
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• v.25 no.1
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• pp.111-122
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• 1996

A model for a system whose state changes continuously with time is introduced. It is assumed that the system is modeled by a Brownian motion with negative drift and an absorbing barrier at the origin. A repairman arrives according to a Poisson process and repairs the system according to an (s,S) policy, i.e., he increases the state of the system up to S if and only if the state is below s. A partial differential equation is derived for the distribution function of X(t), the state of the system at time t, and the Laplace-Stieltjes transform of the distribution function is obtained by solving the partial differential equation. For the stationary case the explicit expression is deduced for the distribution function of the stationary state of the system.

• Proceedings of the KAIS Fall Conference
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• 2010.11b
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• pp.859-861
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• 2010

The construction companies are facing potential EHS(Environment, Health & Safety) of major accidents to cause casualties or a financial loss and increasing social responsibility. So, they have to voluntarily accomplish the EHS management system rather than passively with regard to EHS regulation. In this study, the integrated EHS management system is developed based on cloud computing, and construction companies are to materialize self-regulation EHS process of construction workplace and to standardize the total EHS business process using the developed system. The proposed system also provides risk analysis, education/control and continuous improvement for EHS tasks and users can easily access the system on the web at a low price through cloud computing service. Eventually, the integrated system contributes to the managerial improvement by minimizing economic and physical loss caused by construction accidents.

• Journal of the Korea Safety Management & Science
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• v.12 no.4
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• pp.139-143
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• 2010

The small and medium construction companies are facing potential EHS(Environment, Health & Safety) of major accidents to cause casualties or a financial loss and increasing social responsibility. So, they have to voluntarily accomplish the EHS management system rather than passively with regard to EHS regulation. In this study, the framework of integrated EHS management system is developed based on cloud computing, and construction companies are to materialize self-regulation EHS process of construction workplace and to standardize the total EHS business process using the developed system. The proposed system also provides risk analysis, education/control and continuous improvement for EHS tasks and users can easily access the system on the web at a low price through cloud computing service. Eventually, the integrated system contributes to the managerial improvement by minimizing economic and physical loss caused by construction accidents.

• Journal of Families and Better Life
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• v.2 no.1
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• pp.131-150
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• 1984

The purpose of this study is to explore the family as an interaction system, concentrating on the mutual influences between communication and family development; (1) how Communication patterns affect family relationships, and (2) how relationships among family members affect communication. In order to do this Galvin, Brommel used the following frame work; family is a system in which communication regulates cohesion and adaptability by a flow of message patterns through a defined network of evolving interdependent relationships. A family system consists of members, the relationships among them, the family attributes, the members attributes and an environment in which family functions. Within the framework of common cultural communication patterns, each family has the capacity to develop its own communication code based on the experiences of individual members and the collective family experience. Most of us develop our communication skills within the family context learning both the general cultural language and the specific familial communication code. Communication may be viewed as a symbolic, transactional process as the process of creating and sharing meanings. To say that communication is a process implies a continuous interaction of an indefinite large numbers of variables with a concomitant,. continuous change in the values taken by these variables. Finally the process implies change, Family functions include the primary functions of cohesion and adaptability, and supporting functions of family images, themes, boundaries, and biosocial issues. The primary functions reveal concepts integrated family interaction and supporting function, along with those of cohesion and adaptability, give shape to family life. the characteristics of developed relationships of richness, uniqueness efficiency, substitutability, pacing , openness spontaneity, and evaluation are reflected in the verbal and nonverbal behaviors with which family members negotiated a set of common meanings and develop thier own unique message system. The message system is the major element of communication process and influences both the form and the content of thier relationship and in create and share meanings. Family systems need to provide order and predictability for thier members, specifically focusing on communication rules and the networks by which messages are transmitted. Most rules emerge as a result of multiful interactions. There are basic rules and rules about rules, or metarules. Perceiving the rules of family system is very difficult because often family members don't think about the basic rules, much less the metarules. Breaking the rule may result in the creation of a new set because the system may recalibrate itself to accept more variety of behavior. Families develop communication networks to deal with the general issue. Family adaptability may be seen through the degree of flexibility in forming and reforming networks and networks become a vital part of the decision- making process and relate to the power dynamics operating within the family. Networks also play an integral part in maintaining the roles and rules operating with the family system. Thus networks and rules have mutual influence. The family -of -origin issues influence all aspects of family communication and account for many of the communication patterns, rules and networks and the role of the family -of-origin influences as a primary force for communication on behavior of newly forming systems. Each family system develops its own communication meanings. There is not one right way to communicate within a family but may be indefinitly large change of family life and communication behavior. Study on functional family communication helps to gain a better understanding of dynamics of family communication and ability of a new insight into the family.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.218-228
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• 2020

The material industry is an important infrastructure industry that uses process technology in order to produce parts applied to the final product and determine the quality of the finished product. However, the market environment, which has been recognized as a 3D industry, has deteriorated recently and lost competitiveness compared to other material industry countries. This study analyzed the characteristics of forging companies and The study found that three characteristics of the forging industry, facility-oriented, order-based, and field-centered, and internal failure cost and external failure costs were set as the range of quality cost. A total of eight quality tasks were selected by applying the quality cost management system and continuous quality improvement process developed for large-scale A forging company, and improvement activity proved its effectiveness reducing quality costs by 63.3% compared to the previous year. The research helps forging companies establish a quality management strategy by systematically managing and analyzing quality costs.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.192-192
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• 2000

In this paper, a platoon merging is considered as a remote-controlled system with the state represented by a stochastic process. In this system, it becomes to encounter situations where a single decision maker controls a large number of subsystems, and observation and control signals are sent over a communication channel with finite capacity and significant transmission delays. Unlike classical estimation problem in which the observation is a continuous process corrupted by additive noise, there is a constraint that the observation must be coded and transmitted over a digital communication channel with finite capaci쇼. A recursive coder-estimator sequence is a state estimation scheme based on observations transmitted with finite communication capacity constraint. Using the coder-estimator sequence, the remote control station designs a feedback controller. In this paper, we introduce a stochastic model for the lead vehicle in a platoon of vehicles considering the angle between a road surface and a horizontal plane as a stochastic process. The simulation results show that the inter-vehicle distance and the deviation from the desired inter-vehicle distance are well regulated.

• Journal of the Korean institute of surface engineering
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• v.29 no.2
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• pp.132-139
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• 1996

Experiments on the automatic control of NaOH concentration and on the spraying condition of NaOH solution in the alkaline degreasing process of a continuous hot-dip galvanizing line have been carried out in order to improve degreasing performance of a galvanizing sheet steel using laboratory degreasing and galvanizing simulators. The concentration of NaOH for the good degreasing has been determined to be 6.0% and more and this concentration has been able to be automatically well controlled within $\pm$0.1% by employing a solution electrical conductivity meter under a flow injection analysis condition rather than by employing a sodium ion selective electrode in the degreasing simulator. Frequent blocking of the spraying nozzles of the solution has been reduced considerably by the set-up and periodical operation of an automatic valve system in the nozzle system. By applying this automatic valve system and by automatic controlling the NaOH concentration and other ordinary variables in the degreasing process, the degreasing performance has been increased from the conventional 76% to the new 85%.

• The Korean Journal of Franchise Management
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• v.10 no.4
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• pp.7-18
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• 2019

Purpose: This study identifies the relative importance of the sub - factors of initial services and continuous services using AHP (Analytic Hierarchy Process) method, and calculates the competitive index for the detailed factors. The purpose of this paper is to propose the establishment of long - term and short - term management strategy for expansion of business of food service franchise, franchisors, long - term and win - win relationship with franchisees, and rationalization of operating system. Research design, data, and methodology: The population for the survey is 92 franchisees in 46 foreign brands and 46 domestic brands in the Seoul metropolitan area (Seoul / Gyeonggi / Incheon). The survey was conducted from July 1 to August 31, 2018 through the survey agency with a telephone interview and a surveyor's direct visit. A total of 100 questionnaires were collected, but a total of 92 parts were used for analysis except 8 parts that were considered to contain false information. Using the AHP method, relative importance and competitiveness index were calculated for the details of initial services and continuous services. Results: The results shows continuous services were significantly higher for both foreign brand franchises, domestic brand franchises, and overall than initial services, This suggests that the continuous services of the affiliated franchisors has a higher relative importance than the initial services. Among the continuous services, brand reinforcement and promotion were significantly higher for both foreign brand merchants and domestic brand franchises. This can be regarded as the most important factor in brand reinforcement and promotion when selecting a food service franchisors. Conclusions: In the Standard Terms and Conditions governed by the Fair Trade Commission, the franchisors should increase the fairness by creating manuals for supporting services, especially after opening, and regularly checking whether the supporting services have been carried out like manuals since the establishment of franchisees. In addition, the Brand Strengthening and Public Relations Committee (tentative name) jointly participated by the franchisors and franchisees for the purpose of strengthening and promoting the brand, suggesting a system for transparent and efficient execution of the brand reinforcement and promotion budget and monitoring afterwards.

• Journal of Environmental Science International
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• v.21 no.12
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• pp.1449-1454
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• 2012

The ion selective microelectrodes (ISME) have been applied to observe the continuous profiles of NO3-N and NH4-N in bulk solutions or biofilms. In order to evaluate the performance and applicability of ion concentration measuring system, the characteristics, such as slope of calibration curve, detection limit and potentiometric selectivity coefficient were investigated. The slopes of calibration curve showed high degree of correspondence for each target ion concentrations. And the detection limits of nitrate and ammonia ion selective microelectrode were 10-4.7 M and 10-4.4 M, respectively. These ion selective microelectrodes were proved that their own performance could be maintained for 16 days after making. NO3-N and NH4-N selective microelectrodes were also adapted to detect the continuous ion profiles of cilia media packed MLE (Modified Ludzack-Ettinger) process. And the monitored nitrate and ammonia ion profiles with the ion selective microelectrode were stable and well corresponded to the results with conventional ion chromatograph. However, the electric potential was unstable until 8 hr because of the unknown noise. The tip shape and performance of the ion selective microelectrode was stably kept over 2 days continuous monitoring.