• Proceedings of the KIPE Conference
• /
• 2019.07a
• /
• pp.435-436
• /
• 2019

본 논문은 Platform 기반의 PEBB(Power Electronics Building Block)을 이용한 계통연계형 에너지저장시스템(ESS) PCS의 개발전략과 효율적인 운용 방법에 대해 제안한다. Platform Design이란 표준제조 공정을 통해 다양한 제품을 만들어 내는 기술을 뜻한다. 이 Platform으로 생산되는 Modular PEBB(Power Electronics Building Block)을 이용하여 다양한 용량대의 제품에 대응할 수 있으며, 이를 통해 125kW에서부터 2MW제품까지 병렬확장이 가능하다. PCS의 Platform화로 시스템 용량 확장이 용이하며, 대량 생산이 가능하기 때문에 비용 측면에서의 장점이 있다. 그리고 부분 운전을 통해 운영 효율 향상과 PCS 수명을 늘릴 수 있다. 본 논문에서는 Platform 기반의 PCS의 물리적 및 제어적 구조를 설명하고, 개발전략의 방법에 대해 소개하고자 한다.

• Proceedings of the KIPE Conference
• /
• 2020.08a
• /
• pp.148-150
• /
• 2020

모듈러 구조의 전력변환 장치는 고전류 및 고전력이 요구되는 어플리케이션에 사용한다. 일반적으로 모듈러 구조의 전력변환 장치는 전체 출력 전력을 각각의 단일 전력변환 장치의 출력 전력에 균등하게 분배되도록 제어하여 부하 부담을 모든 개별 전력변환 장치로 분산한다. 하지만 기존의 출력 전력 균등화 제어는 전력변환 장치 간의 전력변환 효율 차이에 대하여 능동적으로 대응할 수 없기 때문에 모듈러 구조의 전력변환 시스템의 전력변환 효율과 신뢰성을 저감할 수 있다. 본 논문에서는 개별 전력변환 장치 간의 실제적인 효율 차이를 고려하여 출력 전력이 아닌 입력 전력에 대하여 모듈러 구조로 구성된 개별 전력변환 장치의 부하를 조절하는 입력 전력 균등화 제어방법을 제안한다. 제안하는 입력 전력 균등화 제어 방법은 2개의 200 W급 모듈러 벅 컨버터를 통해 검증하였다.

• Journal of Microbiology and Biotechnology
• /
• v.19 no.10
• /
• pp.1169-1175
• /
• 2009

An antifungal chitinase, ChiCW, produced by Bacillus cereus 28-9 is effective against conidial germination of Botrytis elliptica, the causal agent of lily leaf blight. ChiCW as a modular enzyme consists of a signal peptide, a catalytic domain, a fibronectin type-III-like domain, and a chitin-binding domain. When two C-terminal domains of ChiCW were truncated, $ChiCW{\Delta}FC$ (lacking the chitin-binding domain and fibronectin type III-like domain) lost its antifungal activity. Since $ChiCW{\Delta}C$ (lacking the chitin-binding domain) could not be expressed in Escherichia coli as $ChiCW{\Delta}FC$ did, a different strategy based on protein engineering technology was designed to investigate the involvement of the chitin-binding domain of ChiCW ($ChBD_{ChiCW}$) in antifungal activity in this study. Because ChiA1 of Bacillus circulans WL-12 is a modular enzyme with a higher hydrolytic activity than ChiCW but not inhibitory to conidial germination of Bo. elliptica and the similar domain composition of ChiA1 and ChiCW, the C-terminal truncated derivatives of ChiA1 were generated and used to construct chimeric chitinases with $ChBD_{ChiCW}$. When the chitin-binding domain of ChiA1 was replaced with $ChBD_{ChiCW}$, the chimeric chitinase named ChiAAAW exhibited both high enzyme activity and antifungal activity. The results indicate that $ChBD_{ChiCW}$ may play an important role in the antifungal activity of ChiCW.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2008.10a
• /
• pp.24-36
• /
• 2008

Architecture-based competition has become a very important issue in many industries. As companies seek lower cost, fast development, and more customizability at the same time, modular architecture of products and processes seem to be an inevitable choice. Existing literature, however, has only focused on the basic contents of architecture-based competition. Different competitive environments and technological competencies of incumbent companies influence the evolutionary dynamics of dominant architecture of industries. In this paper we suggest a new theoretical framework to deal with the complex co-adaptation process of architecture-based competition. We first explore the emerging modular architecture in Chinese commercial vehicle industry, and then compare it with the architecture strategies of Korean companies. Based on the explorative case study, we propose new hypotheses relating the market demand, technological competencies of major players and dominant architecture in an indus-try.

• International Commerce and Information Review
• /
• v.15 no.2
• /
• pp.163-185
• /
• 2013

Chesbrough(2003, 2006) studied Open Innovation about not only IT advanced firms such as Intel or IBM, but also P&G or 3M which are traditional manufacturing firms. As West(2006) described, we can analyze open innovation in several levels such as firm level, industry level, sector, or cluster. Most of all, we could know that according to belonging industries, open innovation effect of firms are different based of technology life cycle, or modular or non modular architecture(JHJ YUN, 2010; JHJ YUN, 2009). In this research, we will study open innovation of Korea aeroplane industry. Korea Aerospace Industries, Ltd is the flagship company in Korean aeroplane industry. We will study the open innovation relationship between Korean Aerospace Industries, Ltd and supplying firms based on Case study and Interview method. Our research question is this. Do supplying firms for Korea Aerospace Industries, Ltd adopt open innovation strategy? If then, what kind of aspects do the open strategies have?

• Proceedings of the Technology Innovation Conference
• /
• 2002.02a
• /
• pp.133-149
• /
• 2002

This study aims to investigate the impact of wide use of digital technology, in particular, the Internet, on innovation process and corporate strategy in electronics industry. The introduction of digital technology has changed innovation process, business model and organizational structure of the electronics companies. With the introduction of digital technology, the entire value chain of electronics industry from procurement, sales, and marketing to R&D and manufacturing has been restructured. E-commerce has been a major agenda for e-business. Recently, collaboration among electronics companies through e-marketplace has emerged as an important issue. A web-based e-commerce standard, so called RosettaNet, has been developed for facilitating e-transactions of electronics firms. The development of digital technology has dramatically increased the processing speed and sophisticated the virtual reality technology. As simulation becomes easier and more effective, the uncertainty and risk involved in R&D has decreased significantly. Another positive impact is closer cooperation between R&D and manufacturing functions. Taking advantage of automated and flexible production technology, has a new type of firm, so called, EMS (Electronics Manufacturing Services) emerged, whose strategic focus is on manufacturing only. The EMS can be seen as a kind of innovative organization, that is, a modular organization for production function. Digital technology has made convergence of computer and communication possible at early years but right now the convergence has been accelerated in extensive areas of communication, broadcasting, information appliances, software, contents, and services. Firms' effort for an innovative product and service has been intensified and the competition for a new standard product and service has become severe in electronics industry. Business activities are always realized in a specific organizational context. Accordingly building up innovation-friendly organization has emerged as a critical concern. Due to the striking decrease of transaction cost, a network type of organization has proliferated, and a business function turns into a modular organization. As a whole, digital technology has pushed electronics firms into developing their own business model, which takes consideration of standardization of business platform and their core competency.

• Proceedings of the Korean Society for Applied Microbiology Conference
• /
• 2002.10a
• /
• pp.18-25
• /
• 2002

The pikromycin biosynthetic system in Streptomyces venezuleae is unique for its ability to produce two groups of antibiotics that include the 12-membered ring macrolides methymycin and neomethymycin, and the 14-membered ring macrolides narbomycin and pikromycin. The metabolic pathway also contains two post polyketide-modification enzymes, a glycosyltransferase and P450 hydroxylase that have unusually broad substrate specificities. In order to explore further the substrate flexibility of these enzymes a series of hybrid polyketide synthases were constructed and their metabolic products characterized. The plasmid-based replacement of the multifunctional protein subunits of the pikromycin PKS in S. venezuelae by the corresponding subunits from heterologous modular PKSs resulted in recombinant strains that produce both 12- and 14-membered ring macrolactones with predicted structural alterations. In all cases, novel macrolactones were produced and further modified by the DesVII glycosyltransferase and PikC hydroxylase leading to biologically active macrolide structures. These results demonstrate that hybrid PKSs in S. venezuelae can produce a multiplicity of new macrolactones that are modified further by the highly flexible DesVII glycosyltransferase and PikC hydroxylase tailoring enzymes. This work demonstrates the unique capacity of the S. venezuelae pikromycin pathway to expand the toolbox of combinatorial biosynthesis and to accelerate the creation of novel biologically active natural products. The polyketide backbone of rifamycin B is assembled through successive condensation and ${\beta}$-carbonyl processing of the extender units by the modular rifamycin PKS. The eighth module, in the RifD protein, contains nonfunctional DH domain and functional KR domain, which specify the reduction of the ${\beta}$-carbonyl group resulting in the C-21 bydroxyl of rifamycin B. A four amino acid substitution and one amino acid deletion were introduced in the putative NADPH binding motif in the proposed KR domain encoded by rifD. This strategy of mutation was based on the amino acid sequences of the corresponding motif of the KR domain of module 3 in the RifA protein, which is believed dysfunctional, so as to introduce a minimum alteration and retain the reading frame intact, yet ensure loss of function. The resulting strain produces linear polyketides, from tetraketide to octaketide, which are also produced by a rifD disrupted mutant as a consequence of premature termination of polyketide assembly. Much of the structural diversity within the polyketide superfamily of natural products is due to the ability of PKSs to vary the reduction level of every other alternate carbon atom in the backbone. Thus, the ability to introduce heterologous reductive segments such as ketoreductase (KR), dehydratase (DH), and enoylreductase (ER) into modules that naturally lack these activities would increase the power of the combinatorial biosynthetic toolbox. The dehydratase domain of module 7 of the rifamycin PKS, which is predicted to be nonfunctional in view of the sequence of the apparent active site, was replaced with its functional homolog from module 7 of rapamycin-producing polyketide synthase. The resulting mutant strain behaved like a rifC disrupted mutant, i.e., it accumulated the heptaketide intermediate and its precursors. This result points out a major difficulty we have encountered with all the Amycolatopsis mediterranei strain containing hybrid polyketide synthases: all the engineered strains prepared so far accumulate a plethora of products derived from the polyketide chain assembly intermediates as major products instead of just analogs of rifamycin B or its ansamycin precursors.

• Nuclear Engineering and Technology
• /
• v.56 no.7
• /
• pp.2756-2766
• /
• 2024

Small rod-controlled pressurized water reactors (PWR) are the ideal energy source for vessel propulsion, benefiting from their high reactivity control efficiency. Since the control rods (CRs) increase the complexity of reactivity control, this paper seeks to study the performance of CRs in small rod-controlled PWRs to extend the lifetime and reduce power offset due to CRs. This study investigates CR grouping, move-in/out strategies, and axially non-uniform design effects on core neutron physics metrics. These metrics include axial offset (AO), core lifetime (CL), fuel utilization (FU), and radial power peaking factor (R-PPF). To simulate the movement of the CRs, a "Critical-CR-burnup" function was developed in OpenMC. In CR designs, the CRs are grouped into three banks to study the simultaneous and prioritized move-in/out strategies. The results show CL extension from 590 effective full power days (EFPDs) to 638-698 EFPDs. A lower-worth prioritized strategy minimizes AO and the extremum values decrease from -0.69 and + 0.81 to -0.28 and + 0.51. Although an axially non-uniform CR design can improve AO at the beginning of cycle (BOC), considering the overall CR worth change is crucial, as a significant decrease can adversely impact axial power distribution during the middle of cycle (MOC).

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.27 no.12
• /
• pp.133-140
• /
• 2013

Cascaded H-Bridge multi-level inverters can be implemented through the series connection of single-phase modular power bridges. In recent years, multi-level inverters are becoming increasingly popular for high power applications due to its improved harmonic profile and increased power ratings. This paper presents a control method for balancing the dc-link voltage and ride-through enhancement, a modified pulse width-modulation Compensation algorithm of cascaded H-bridge multi-level inverters. During an under-voltage protection mechanism, causing the system to shut down within a few milliseconds after a power interruption in the main input sources. When a power interruption occurs finish, if the system is a large inertia restarting the load a long time is required. This paper suggests modifications in the control algorithm in order to improve the sag ride-through performance of ac inverter. The new proposed strategy recommends maintaining the DC-link voltage constant at the nominal value during a sag period, experimental results are presented.

• Smart Structures and Systems
• /
• v.18 no.4
• /
• pp.663-682
• /
• 2016

Continuum manipulators as a kind of mechanical arms are useful tools in special robotic applications. In medical applications, like colonoscopy, a maneuverable thin and flexible manipulator is required. This research is focused on developing a basic module for such an application using shape memory alloys (SMA). In the structure of the module three wires of SMA are uniformly distributed and attached to the circumference of a flexible tube. By activating wires, individually or together, different rotation regimes are provided. SMA model is used based on Brinson work. The SMA model is combined to model of flexible tube to provide a composite model of the module. Simulating the model in Matlab provided a platform to be used to develop controller. Complex and nonlinear behavior of SMA make the control problem hard especially when a few SMA actuators are active simultaneously. In this paper, position control of the two degree of freedom module is under focus. An experimental control strategy is developed to regulate a desired position in the module. The simulation results present a reasonable performance of the controller. Moreover, the results are verified through experiments and show that the continuum module of this paper would be used in real modular manipulators.