Earticle

타임루프는 등장 인물에게 반복되는 시간의 주기를 경험하게 하는 장치로, 주기적 시간에서의 반복적 실패 를 통해서 문제를 파악하고 해결하는 과정이 드러나 있는 것이 특징이다. 본 논문에서는 타임루프 장치를 통한 반복이 게임의 전개와 플레이어의 경험에 어떤 작용을 하는지 알아보기 위해 게임 ‘12 Minutes’을 중심 으로 게임요소와 스토리텔링을 살펴보았다. 이를 위해 게임에서 타임루프로 인지되는 인터랙션이 무엇이고, 그 안에서 플레이어 캐릭터와 플레이어의 위치, 게임의 목표와 분기점이 어떻게 변화하는지 분석하였다. 그 결과, 다음과 같은 사실을 알게 되었다. 첫째, 타임루핑 게임에서 반복적 인터랙션은 오브젝트와 플레이어, 캐릭터 사이에 일어나는데, 루핑을 알고 있는 존재는 플레이어 캐릭터와 플레이어로 타임루핑은 플레이어 차원과 플레이어 캐릭터 차원에서 일어난다는 점이다. 둘째, 게임에서 타임루프는 다중의 서사를 만들어내 는 플랫폼으로 문제해결을 위한 다양한 시도가 가능하고, 플레이어가 가상 세계에 행하는 행위를 통해 자신 의 욕망하는 바를 잘 드러낼 수 있도록 기능하는 장치라는 것이다.

The time loop is a device that allows characters to experience repeated cycles of time, and it is characterized by the process of identifying and solving problems through repeated failures in periodic time. In this paper, game elements and storytelling were examined, focusing on the game '12 Minutes', to find out how repetition through the time loop device affects the development of the game and the player's experience. In addition to the interaction perceived as a time loop in the game, it was analyzed how the function of the player character and the player, the game's goal and turning point change in it. As a result, the following facts were found out. First, in a time looping game, repetitive interactions occur between an object, characters, and a player. So the player character and the player are aware of looping, and time looping occurs in the player's dimension and also the player character's dimension. Second, the time loop in the game is a platform that creates multiple narratives, enabling various attempts to solve problems. Moreover, it is a device that players can express their desires well through the actions they take in the virtual world.

Small loop electromagnetic (EM) method has the ability to provide continuous conductivity distribution at shallow depth. Especially, this method is very suitable for monitoring conductivity variation in the subsurface because data acquisition is very rapid and non-destructive. In this study, we developed a time-lapse inversion algorithm to effectively interpret monitoring data. The developed inversion algorithm imposes a big penalty on model parameter with small change, while a minimal penalty on model parameter with large change compared with a reference model. Consequently, inversion result shows a focused image where model parameters changed greatly. Applying the method on the inversion of synthetic 2.5D small loop EM monitoring data, we can ensure that it is effective in the detection of areas which show great change between a reference and time-lapse model.

본 논문에서는 다양한 실시간 이더넷 프로토콜에 쉽게 적용할 수 있는 폐루프 스테핑 모터 드라이브를 개발하는 방법을 제안한다. 제안 방법은 다양한 유형의 실시간 이더넷 프로토콜에 공용으로 재사용할 수 있는 모터 드라이브 모듈과 각 실시간 이더넷 프로토콜마다 개발되는 통신 인터페이스 모듈로 나누어진다. 또한 계층적 구조를 사용하여 모션 제어 알고리즘을 다양한 실시간 이더넷 프로토콜과 모션 프로파일에 독립적으로 재사용할 수 있도록 하였다. 제안하는 방법을 검증하기 위해 EtherCAT 및 Mechatrolink III를 활용하여 폐루프 모터 드라이브를 개발하였으며, 실시간 이더넷 기반에 서 정상적으로 제어되는 것을 확인하였다. 개발한 EtherCAT 및 Mechatrolink III의 실시간 통신 성능을 확인하기 위해 Cycle time을 측정하였으며, 그 결과 32개의 모터 드라이브를 연결한 경우 EtherCAT이 Mechatrolink III 보다 7.5배 정도 더 빠른 것을 확인하였다.

This paper proposes the design of a closed-loop stepping motor drive for real-time Ethernet (RTE), which can be easily applied to a variety of RTE protocols. The proposed design is divided into a closed-loop step motor drive which can be reused for various types of RTE protocol and RTE module developed for each specific RTE protocol. It is based on a layered architecture so that the motion control algorithm can be easily reused independently of the RTE protocol and motion profile. To verify the proposed design, closed-loop motor drives based on EtherCAT and Mechatrolink III were developed and their performances were evaluated. Cycle time was measured to verify the real-time communication performance of the developed EtherCAT and Mechatrolink III based motor drive. As a result, the EtherCAT was 7.5 times faster than the Mechatrolink III when 32 motor drives were connected.

이 논문은 거리예술 <LOOP STOP: BROKEN BRIDGE>를 바탕으로 시공간을 초월한 협업과 소통을 위한 영상 기법 및 제 작 과정, 의도에 주목하였다. 본 작품은 한국과 프랑스 창작자들의 협업이며, 2020년 10월 17일과 18일, 한국은 한강의 노들 섬에서 한국 시간 20시에 프랑스는 리옹에 위치한 콤플렉스 카파르나움 스튜디오에서 프랑스 시간 13시에 동시에 발표되었 다. 이러한 작품 형태의 배경에는 코로나-19로 인한 팬데믹 시대를 배제 할 수 없다. 온라인 기반의 제작이 될 수밖에 없는 상황에서 창작자들은 어떻게 교류하고 제작할 것인가를 고민해야 했다. 연구자는 이와 같은 상황에서 작품을 제작하면서 영 상이 가진 시간성과 공간성의 교류 및 공유의 역할에 대해 논의할 필요가 있다고 판단하였다. 연구목적은 온택트 시대의 온라 인 기반의 제작사례 및 영상 기법의 효율적 활용에 대한 모색이다. 연구방법은 거리예술 <LOOP STOP: BROKEN BRIDGE>를 중심으로 제작과정과 기술적 성과들을 기록하는 방식으로 진행되었다. 본론은 2장 ‘작품의 개요 및 구성’과 3장 ‘<LOOP STOP: BROKEN BRIDGE>에서 사용된 시공간의 공유와 확장을 위한 영상기법’을 소개하였다. 3장의 각 기법은 ‘라이브 스트리밍’, ‘프로젝션’, ‘다면’, ‘중첩’을 주요 사례로 구분하였다. ‘V-link를 활용한 라이브 스트리밍’은 ‘상호작용’, ‘고 정식과 이동식 프로젝션의 혼용 및 관객의 이동’은 ‘움직임’, ‘화상회의 시스템을 이용한 다면’은 ‘경계선, 퍼즐, 몽타주’, ‘라이 브 스트리밍과 프로젝션을 이용한 중첩’은 ‘동시성’의 개념으로 시공간을 공유하고 확장하였다는 연구결과를 얻었다. 본 연구 가 뉴노멀 시대에 영상을 활용한 창작에 관한 참고자료로서 역할하기를 기대한다.

This paper focuses on video techniques, production processes, and intentions to collaborate and communicate that transcend time and space based on the street art <LOOP STOP: BROKEN BRIDGE>. This work was done in collaboration between Korean and French creators. On October 17 and 18 of 2020, on Nodeul Island in the Han River, Korea, at 20:00 Korean time, and at the Komplex Kapharnaum Studio located in Lyon, at 13:00 France time, both teams worked simultaneously. The explanation for the form of these works and their creation is the pandemic caused by COVID-19. In a situation where online-based production was inevitable, the creators had to think about how to interact and how to produce the work. It was judged that it was necessary for the researcher to discuss the role of the exchanging and sharing of the temporality and spatiality of video while producing works in such a context of the times. The purpose of this paper is to search for online-based production cases in the ontact era and to search for efficient uses of imaging techniques. The research method is to be conducted in a way that records the production processes and technical achievements, focusing on the street art <LOOP STOP: BROKEN BRIDGE>. The main body is the second chapter, entitled 'Outline and composition of the work', along with the third chapter, 'Imaging techniques for sharing and expanding the time-space used in <LOOP STOP: BROKEN BRIDGE>'. In the third chapter, 'live streaming', 'projection', 'multiscreen' and 'superimposing' are the main video production techniques studied and classified depending on the case. The research result pertaining to the sharing and expanding of space and time with 'live streaming using V-link' is the concept of 'interaction'; that for 'a mix of fixed and mobile projection and the movement of the audience' is the concept of 'movement'; those for 'multiscreen using a video conferencing system' are the concepts of 'borderline, puzzle, and montage'; and that for 'superimposition using live streaming and projection' is the concept of 'simultaneity'. It is expected that the results here will serve as reference materials for those involved in creation techniques using moving images in the new normal.

최근 한국에서 발생한 Salmonella로 인한 식중독 사고는 2018년 9월 학교급식에서 제공된 초콜릿 무스 케이크가 원인이 되었다. 이 연구의 목적은 Salmonella Typhimurium이 인위적으로 접종된 무스케이크와 티라미수에서 3M Molecular Detection Assay 2 - Salmonella와 식품공전에 등재된 방법인 분리배지와 real-time PCR을 비교하는 것이었다. 무스케이크 2종과 티라미수 2종 25 g에 225 mL BPW를 넣고 $37^{\circ}C$에서 24시간 동안 증균 배양하였다. 배양 후, 3M Molecular Detection Assay 2 - Salmonella, 분리배지 그리고 real-time PCR로 분석하였다. 초콜릿 무스 케이크를 제외하고 3가지 방법은 유사한 결과를 보였다. 초콜릿 무스 케이크에서 분리배지와 3M Molecular Detection Assay 2 - Salmonella는 모든 접종수준에서 동일한 결과를 나타낸 반면 real-time PCR은 $10^4CFU/25g$ 수준에서 1번의 양성결과를 제외하고 모두 검출되지 않았다. 초콜릿 무스에 S. Typhimurium을 $10^2CFU/25g$ 수준으로 접종하였을때, real-time PCR를 이용한 검출은 15%에서는 부분적인 음성을 나타냈고, 20-100% 함량의 초콜릿 무스에서는 모두 음성이었다. Real-time PCR로는 chocolate이 15% 이상 함유된 식품에서의 Salmonella균 검출이 불가능하였지만, LMAP 기반의 3M Molecular Detection Assay 2으로는 chocolate 농도에 관계없이 검출이 가능하였다.

Salmonella spp. are frequently associated with food and are among the most important foodborne pathogens. The recent Salmonella out breaks in Korea was associated with chocolate mousse cakes served with school meals during September 2018. The objective of this research was to compare the 3M Molecular Detection Assay 2 - Salmonella and the Korean Standard Method of Salmonella in artificially inoculated mousse (chocolate and cheese) and tiramisu cakes. Mousse (chocolate and cheese) and tiramisu cakes were artificially inoculated with S. Typhimurium. Twenty five gram of sample was enriched with 225 mL buffered peptone water for incubation at $37^{\circ}C$ for 24 h. After enrichment, the cultures were analyzed by using the 3M Molecular Detection Assay 2 - Salmonella and the Korean Standard Method. Most of the inoculated samples showed similar results except the chocolate mousse cakes, in which real-time PCR was unable to detect S. Typhimurium even after $10^4CFU/25g$ of inoculation. However, S. Typhimurium inoculated at a concentration of $10^0CFU/25g$ was detected by using 3M Molecular Detection Assay 2 - Salmonella. In chocolate mousse, detection of S. Typhimurium using real-time PCR was partially successful when dark chocolate was added at less than 15%. Negative results in real-time PCR and 3M Molecular Detection Assay 2 - Salmonella were confirmed by gel electrophoresis. The data indicated that dark chocolate could inhibit amplification of the target gene in the PCR reactions. In conclusion, the 3M Molecular Detection Assay 2 - Salmonella was better than the Korean Standard Method (real-time PCR) for the detection of S. Typhimurium in chocolate mousse cakes and chocolate mousse.

식품에 존재하는 병원균을 신속검출하기 위한 방법으로 LAMP와 real-time PCR 방법을 비교 평가 하였다. S. Typhimurium, L. monocytogenes, C. sakazakii의 3종에 대해 식품공전에서 권고하는 식품 종류를 선별하여 민감도를 분석하였다. S. Typhimurium에서는 11종의 식품(햄, 닭가슴살, 계란, 돼지고기, 소고기, 오리고기, 액상음료, 샐러드, 콘프레이크, 초콜릿, 사료)중 4종(햄, 돼지고기, 시리얼, 사료)에서 LAMP보다 real-time PCR에서 검출 민감도가 10배 이상 더 높았고, 6종(닭가슴살, 계란, 소고기, 오리고기, 음료, 샐러드)에서는 real-time PCR과 비슷한 수준을 그리고 초콜릿에서는 real-time PCR로는 검출되지 않았으며 LAMP로만 검출되는 결과가 나타났다. L. monocytogenes와 C. sakazakii에서는 9종 모두에서 LAMP보다 real-time PCR에서 검출 민감도가 더 높았다. 또한 L. monocytogenes에서 LAMP의 검출 민감도가 S. Typhimurium과 C. sakazakii 보다 10배 이상 낮았다. 3M MDS의 검출한계 향상을 위해 변형된 3M MDS의 민감도는 기존대비 10배 이상 증가되었다. 따라서 식품에 존재하는 병원균의 검출을 위해 식품의 구성성분에 따라 LAMP와 real-time PCR를 적절히 선택하는 것이 바람직할 것으로 생각되었다. 한편, 농축 방법을 이용해 LAMP방법의 민감도를 향상시킬 수 있음을 알 수 있었다.

The objective of this research was to compare loop-mediated isothermal amplification (LAMP) with real-time polymerase chain reaction (PCR) for the rapid detection of pathogens in foods. In this study, the limits of detection (LODs) for Salmonella Typhimurium, Listeria monocytogenes, and Cronobacter sakazakii were evaluated in various foods. Among 11 samples tested for S. Typhimurium, LAMP and real-time PCR had the same LODs in beef and duck meat whereas real-time PCR was more sensitive than the LAMP in 8 samples. However, S. Typhimurium in chocolate samples was not detected by real-time PCR. The sensitivity of real-time PCR was high in all samples inoculated with L. monocytogenes and C. sakazakii whereas LAMP was more sensitive than real-time PCR in oil-rich foods. Therefore, LAMP can be shown as an easrer, more convenient method, as well as effective analytical method for testing difficult samples when employed in PCR.

본 연구에서는 LAMP(3M^TM MDS), RT-PCR (VERI-Q PCR 204), 선택배지(PALCAM)를 이용하여 in vitro 상과 식품에서 L. monocytogenes의 검출 능력에 대하여 비교 및 평가하였다. DNA 증폭에 영향을 최소화하는 증균배지에서 배양된 L. monocytogenes를 10⁰-10³ CFU/mL 농도로 희석 후 세 가지 방법으로 검출한 결과, 선택배지, LAMP, RT-PCR 순으로 정확도가 높았으며, 세 가지 방법 모두에서 위양성과 위음성은 검출되지 않았다. 농산물(3종류), 축산물(2종류), 수산물(6종류)에 10⁰-10³ CFU/25 g의 수준으로 L. monocytogenes를 접종 후 세 가지 방법으로 검출한 결과, 농산물과 축산물에서는 LAMP와 선택배지가 동등한 수준의 정확도를 보였지만, 수산물에서는 선택배지, LAMP, RT-PCR 순으로 정확하였다. LAMP와 선택배지는 모든 샘플에서 L. monocytogenes를 검출하였지만, RT-PCR은 10⁰ CFU/25 g으로 접종된 수산물(바지락살, 광어)에서 L. monocytogenes를 검출하지 못했다. 정확도의 측면에서 선택배지가 가장 정확도가 높았지만 확정까지의 시간이 오래 소요된다는 점에서, 그리고 RT-PCR은 증균배지나 식품에 존재하는 여러 inhibitor의 영향을 받는다는 점에서, LAMP는 식품에 존재하는 L. monocytogenes의 신속 검출 방법으로서 효과적으로 활용될 수 있음을 알 수 있었다.

Listeria monocytogenes is a foodborne pathogen causing listeriosis, which can be fatal in specific high-risk groups. The aim of this study was to compare the performance (accuracy, sensitivity, and specificity) of 3M^TM Molecular Detection System (3M^TM MDS) and Korean Food Codex [real-time PCR (RT-PCR) and selective agar] for the detection of L. monocytogenes in various food matrices. The detection performance of the three methods was determined against 10⁰-10³ CFU/mL of L. monocytogenes in vitro and showed high accuracy in the order of RT-PCR, 3M^TM MDS, and selective agar. There was no difference in sensitivity and specificity of the three methods. Eleven food matrices, selected from agricultural, livestock, and seafood products, were artificially inoculated with 10⁰-10³ CFU/25 g of L. monocytogenes and enriched in 3M^TM Demi-Fraser Broth. None of the three methods could completely detect low concentrations of L. monocytogenes in a food matrix. However, 3M^TM MDS, which is a loop-mediated isothermal amplification (LAMP)-based technology for rapid detection, showed a higher positive detection rate than RT-PCR did, but lower than that of selective agar. These data indicated that 3M^TM MDS was superior for the rapid detection of L. monocytogenes, compared to RT-PCR in food matrices containing various inhibitors. Consequentially, the study findings suggest that the LAMP method is a promising alternative to RT-PCR for the rapid detection of foodborne pathogens.

The purpose of this study was to develop a real-time quantitative loop-mediated isothermal amplication (LAMP) method for the rapid, sensitive, and convenient detection of Listeria monocytogenes in food. The LAMP method could amplify the hlyA gene of L. monocytogenes successfully at $63^{\circ}C$ with a loopamp real-time turbidimeter. The detection limits of the LAMP for hlyA gene were 6 colony forming units (CFU)/tube. A standard curve was generated for L. monocytogenes LAMP by plotting the graph based different log CFU values of L. monocytogenes and time of positivity through real-time monitoring of the amplication. Then, the LAMP method was employed to test 94 retail food samples effectively. Sensitivity in detection of L. monocytogenes by the LAMP was higher than that of PCR and none of the conventional method-positive samples was missed by the LAMP method.

This paper presents improved empirical representations of a general class of open-loop unstable systems using closed-loop system identification. A multi-axis magnetic-levitation (maglev) nanopositioning system with an extended translational travel range is used as a test model to verify the closed-loop system-identification method presented in this paper. A closed-loop identification technique employing a known controller structure is used for model identification and validation. Direct and coupling transfer functions (TFs) are then derived from the experimental input-output time sequences and the knowledge of controller dynamics. A persistently excited signal with a bandwidth in the frequency range of interest is used as a reference input. An order-reduction algorithm is developed to obtain TFs with predefined orders, which gives the closest match in the frequency range of interest without missing any significant plant dynamics. The entire analysis is performed in the discrete-time domain in order to avoid any errors due to continuous-to-discrete-time conversion and vice versa. Continuous-time TFs are used only for order-reduction and performance analysis of the identified TFs. Experimental results are presented in the time as well as frequency domains to verify the accuracy of the identified plant TFs. These results also demonstrate the effectiveness of the developed closed-loop identification method in meeting all of the three core objectives-(i) reduction in cross-axial coupling from 9.213 ${\mu}m$ to 0.911 ${\mu}m$ in translation and from 22.03 ${\mu}rad$ to 1.353 ${\mu}rad$ in rotation, (ii) large range motion capability with a travel range of ${\pm}2.9$ mm, and (iii) improved robust stability.

Polymer electrolyte membrane (PEM) fuel cell is one of the popular renewable energy sources and widely used in commercial medium power areas from portable electronic devices to electric vehicles. In addition, the increased integration of the PEM fuel cell with power electronics, dynamic loads, and control systems requires accurate electrical models and simulation methods to emulate their electrical behaviors. Advancement in parallel computation techniques, various real-time simulation tools, and smart power hardware have allowed the prototyping of novel apparatus to be investigated in a virtual system under a wide range of realistic conditions repeatedly, safely, and economically. This paper builds up advancements of optimized model constructions for a fuel cell stack system on a real-time simulator in the view points of improving dynamic model accuracy and boosting computation speed. In addition, several considerations for a power hardware-in-the-loop (PHIL) simulation are provided to electrically emulate the PEM fuel cell stack system with power facilities. The effectiveness of the proposed PHIL simulation method developed on Opal RT's RT-Lab Matlab/Simulink based real-time engineering simulator and a programmable power supply is verified using experimental results of the proposed PHIL simulation system with a Ballard Nexa fuel cell stack.

FLL (Frequency Locked Loop) is the core block for high-speed transceiver. It incorporates a PLL for fine locking action, and a coarse controller for coarse locking action. A coarse controller compares frequencies coarsely and is applied to detected frequency difference directly. Compare to conventional FLL, frequency is applied to proposed FLL. Proposed FLL in this paper achieves only 5 cycles for coarse lock and total frequency locking time is 5 times faster than conventional FLL. Thus, proposed FLL is more useful to Ethernet transceiver application that requires high-speed data transfer than conventional FLL. Proposed FLL is based on $0.18{\mu}m$ process.

Physical systems axe generally continuous-time in nature. However as the data measured from these systems is generally in the form of discrete samples, and most modern signal processing is performed in the discrete-time domain, discrete-time models are employed. This paper describes methods for estimating the coefficients of continuous-time system within a closed loop control system. The method employs a recursive estimation algorithm to identify the coefficients of a discrete-time bilinear-operator model. The coefficients of the discrete-time bilinear-operator model closely approximate those of the corresponding continuous-time Laplace transform transfer function.

This paper presents an algorithm for an active power filter which can be used in both single-phase and three-phase electric system. The proposed algorithm focuses on the extraction of harmonic component of load current in each phase and in order to verify the validity of the proposed algorithm while loads are nonlinear, simulations have been done by PLECS software and tested by typhoon-HIL which is real time emulator.

F-18 FDG PET is useful for monitoring residual or recurrent tumors after surgical resection. We describe five F-18 FDG PET images of three patients who had cervical carcinoma and then underwent a loop electrosurgical excision procedure (LEEP). Two of the images were taken within 15 days and three at least 2 months after LEEP. The earlier F-18 FDG PET images revealed linear hypermetabolic lesions in the cervix that were produced by inflammation. This was confirmed by pathological analysis. The later F-18 FDG PET images did not reveal any remarkable hypermetabolism in the cervix without any treatment. These observations suggest that, to determine the response to LEEP therapy, F-18 FDG PET should not be performed within 15 days of the procedure.

A mock circulatory loop system has been developed to construct a simulator for trainees in cardiopulmonary bypass systems or to simulate a test environment for cardiac-assist devices. This paper proposes a computerized mock circulatory loop system whose node is modularized by using a servo control flow regulator to simulate dynamic change of the hemodynamic status. To observe the effect of time-varying resistance, one with hemodynamic properties, the proposed system replicates the planned cross-sectional areas of the outlet of a ventricular assist device in terms of voltage input of a servo valve. The experiment is performed (1) for steady-input commands of selected area sizes and (2) for dynamic commands such as monotonous increase and decrease, and oscillatory functions of the voltage input, and a computer program based on LabVIEW (National Instruments, Austin, USA) processes every measured data and control command to the servo valve. The results show that the pressure and flow at the target points with respect to time-varying resistance match intuitive estimation: the pressure at the outlet and the pressure drop between both sides of the valve increased and the flow at the outlet decreased for increased resistance.

In this paper, control theoretic approaches are proposed to guarantee QoS (Quality of Series) such as packet delay and packet loss of real-time traffic in high-speed communication network. Characteristics of variable rate real-time traÆc in communication networks are described. The mathematical model describing networks including source and destination nodes are suggested. By a traffic control mechanism, it is shown that worst-case end-to-end transfer delay of traffic can be controlled and packet loss can be prevented. The simulation shows results of delay control and buer level control to raise QoS in realtime traffic.

Due to finite bandwidth of missile dynamics, guidance commands in PN guidance tend to diverage as the missile approaches to the target. In this paper, a new method based on the short-time stability theorem is introduced to extend the stability region.

As ultra-wideband impulse radio (UWB-IR) uses short-duration impulse signals of nanoseconds, even a small number of timing errors can cause a detrimental effect on system performance. A delay-locked loop (DLL) is proposed to synchronize and reduce timing errors. The design of the DLL is vital for UWB systems. In this paper, an improved DLL is introduced to a UWB-IR time-hopping spread-spectrum system. Instead of using only two central correlator branches as in a conventional DLL, the proposed system uses two additional correlator branches with different delay parameters and different weight parameters. The performance of the proposed schemes with the optimal parameters is compared with that of traditional schemes through simulation: the proposed four-branch DLLs achieves less tracking jitter or a longer mean time to lose lock (MTLL) than the conventional two-branch DLLs if proper parameters are chosen.

An optimization problem minimizing n given time-weighted performance index for discrete-time linear multi-input systems is investigated for the prespecified closed-loop eigenvalues. Necessary conditions for an optimality of the controller that satisfies the specified closed-loop eigenvalues are derived. A computational algorithm solving the optimal constant feedback gain is presented and a numerical example is given to show the effect of a time-weighted performance index on the transient responses.