• 한국조경학회지
• /
• 제19권3호
• /
• pp.72-86
• /
• 1991

In the study I analyzed the relationship between the characteristics of the user's residential environment and his or her use of openspace. I find out that there are little correlationship between building form and use factors. Also, there are no relationship between persons per room and use factors. Only the physical distance and the location of the building site is correlated with the use factor. In testing the hypotheses, I discovered very little to support the "physical deterministic" notion. I generally was not able to explain the behavior of open space users on the basis of the physical parameters selected to describe the user's residential environment. This, I believe, indicates that there probably are many other variables that play a more important role than those pertaining to the density and form of the residential environment. It is necessary to find out more variables affecting the use of openspace in the neighbourhoods, such as the charecteristics of user group. Also, it is necessary to apply the study to the other sites or the other cities in Korea to compare with the results.

• 소음진동
• /
• 제9권4호
• /
• pp.643-651
• /
• 1999

A brief description of the current technology (contact-start-stop) employed in most of today's hard disk drive is presented. The dynamics and head/disk interactions during a start/stop process are very complicated and no one has been able to accurately model the interactions. Thus, the head/disk interface that meets the start/stop durability and stiction requirements are always developed statistically. In arriving at a solution. many sets of statistical tests are run by varying several parameters. such as, the carbon overcoat thickness. lubricant thickness. disk surface roughness, etc. Consequently, the cost associated III developing an interface could be significant since the outcome is difficult to predict. An alternative method known as Load/Unload technology alters the problem set. such that. the start/stop performance can be designed in a predictable manner. Although this techno¬logy offers superior performance and significantly reduces statistical testing time, it also has some potential problems. However. contrary to the CSS technology. most of the problems can be solved by design and not by trial and error. One critical problem is that of head/disk contacts during the loading and unloading processes. These contact can cause disk and slider damage because the contacts are likely to occur at high disk speeds resulting in large friction forces. Use of glass substrate disks also may present problems if not managed correctly. Due to the low thermal conductivity of glass substrates. any head/disk contacts may result in erasure due to frictional heating of the head/disk interface. In spite of these and other potential problems. the advantage with L/UL system is that these events can be understood. analyzed. and solved in a deterministic manner.

• 한국정보처리학회논문지
• /
• 제4권5호
• /
• pp.1327-1336
• /
• 1997

I/O FSM 모델로 표현된 프로토콜들로부터의 시험 계열 생성은 I/OFSM 명세 자체가 강하게 접속되어야 하며 (strongly connected) 상태(state) 수가 최소(minimal)하여야 하며, 그리고 또 결정형(determinstic) 이어야 한다는 가정에서 출발한다. 본 논문에서는 프로토콜을 나타내는 명세 I/OFSM(또는 Graph)이 이러한 가정으로 출발 되는 이유를 객관화 시키고, 또 그래프 재표기 시스템(Graph Rewriting System)을 정의하고, 이를 명세 그래프(명세 I/OFSM)에 적용시켜 기존의 알고리즘보다 훨씬 빨리 강한 접속 여부를 판단하는 알고리즘을 제시한다.

• 정보처리학회논문지D
• /
• 제14D권6호
• /
• pp.649-656
• /
• 2007

오늘날 차량네트워크(CAN)는 전기적 강인, 저가격과 접근지연 때문에 분산 임베디드 시스템에서 널리 사용되는 버스형 필드이다. 그러나 버스토폴로지에서 발생하는 의존적인 제한 때문에 차량네트워크가 어플리케이션상에서 안전적으로 사용되는지는 논쟁되어왔다. 그래서 차량네트워크(CAN) 디자인 단계 동안 데이터 버스의 부하와 최대 지연, 경쟁 우선순위와 같은 네트워크의 성능을 분석하는 것이 중요하게 되었다. 이 논문은 차량네트워크의 성능을 평가하기 위해 사용된 시뮬레이션 알고리즘과 고장 기법 기술을 적용을 소개한다. 이는 차량네트워크의 어떤 산만한 구현의 줄임과 시스템의 신뢰성을 향상 시켜 줄 것이다.

• 한국음향학회지
• /
• 제21권3호
• /
• pp.221-229
• /
• 2002

본 논문에서는 Monte-Carlo 방법으로 빔패턴 오차의 허용범위를 만족하는 개별소자의 허용오차를 규정하였다. 일반적으로 사용되는 통계적인 방법은 불규칙한 특성을 갖는 랜덤오차를 정규분포를 갖는 랜덤 변수로 모델링을 하여 개별소자의 오차범위를 규정하는데, 이러한 방법은 해석하고자 하는 배열소자의 개수증가에 따라 계산량이 지수승으로 늘어나게 되어 많은 소자배열에는 적합하지 않게 된다. 이러한 단점을 보완하기 위해서 이 논문에서는 Monte-Carlo 방법을 사용하여 배열소자의 증가에 따른 계산량의 증가를 줄이는 새로운 알고리즘을 제안하였다. 그리고 이렇게 규정된 오차의 범위를 간단한 모의실험을 통해서 검증하였다.

• Bioinformatics and Biosystems
• /
• 제2권1호
• /
• pp.28-32
• /
• 2007

The protein phosphorylation is one of the important processes in the cell signaling pathway. A variety of protein kinase families are involved in this process, and each kinase family phosphorylates different kinds of substrate proteins. Many methods to predict the kinase-specific phosphoryrated sites or different types of phosphorylated residues (Serine/Threonine or Tyrosin) have been developed. We employed Supprot Vector Machine (SVM) to attempt the prediction of protein kinase specific phosphorylation sites. 10 different kinds of protein kinase families (PKA, PKC, CK2, CDK, CaM-KII, PKB, MAPK, EGFR) were considered in this study. We defined 9 residues around a phosphorylated residue as a deterministic instance from which protein kinases determine whether they act on. The subsets of PSI-BALST profile was converted to the numerical vectors to represent positive or negative instances. When SVM training, We took advantage of multiple SVMs because of the unbalanced training sets. Representative negative instances were drawn multiple times, and generated new traing sets with the same positive instances in the original traing set. When testing, the final decisions were made by the votes of those multiple SVMs. Generally, RBF kernel was used for the SVMs, and several parameters such as gamma and cost factor were tested. Our approach achieved more than 90% specificity throughout the protein kinase families, while the sensitivities recorded 60% on average.

• 전자공학회논문지C
• /
• 제35C권9호
• /
• pp.29-37
• /
• 1998

가중 무작위 패턴 테스트에서 적은 수의 가중 무작위 패턴을 사용하여 높은 고장 검출율을 달성하기 위해서는 최적화된 가중치 집합들을 찾아내야만 한다. 따라서 최적화된 가중치 집합을 찾아내려는 많은 연구가 행해져 왔다. 이 논문에서 결정론적인 테스트 패턴에 대한 샘플링 확률을 기반으로 하여 최적화된 가중치 집합을 효율적으로 찾는 새로운 가중치 집합 최적화 알고리듬을 제한한다. 아울러 시뮬레이션을 통해 적당한 최대해밍거리를 구하는 방법도 소개된다. ISCAS 85 벤치마크 회로에 대한 실험결과는 새로운 가중치 집합 최적화 알고리듬과 적절한 최대 해밍거리를 구하는 방법의 효율성을 뒷받침해 준다.

• Journal of Communications and Networks
• /
• 제6권1호
• /
• pp.68-77
• /
• 2004

In the near future packet networks should support applications which can not predict their traffic requirements in advance, but still have tight quality of service requirements, e.g., guaranteed bandwidth, jitter, and packet loss. These dynamic characteristics mean that the sources can be made to modify their data transfer rates according to network conditions. Depending on the customer&; needs, network operator can differentiate incoming connections and handle those in the buffers and the interfaces in different ways. In this paper, dynamic QoS-aware scheduling algorithm is presented and investigated in the single node case. The purpose of the algorithm is in addition to fair resource sharing to different types of traffic classes with different priorities ?to maximize revenue of the service provider. It is derived from the linear type of revenue target function, and closed form globally optimal formula is presented. The method is computationally inexpensive, while still producing maximal revenue. Due to the simplicity of the algorithm, it can operate in the highly nonstationary environments. In addition, it is nonparametric and deterministic in the sense that it uses only the information about the number of users and their traffic classes, not about call density functions or duration distributions. Also, Call Admission Control (CAC) mechanism is used by hypothesis testing.

• Smart Structures and Systems
• /
• 제3권2호
• /
• pp.189-200
• /
• 2007

As a functional material, shape memory alloy (SMA) has attracted much attention and research effort to explore its unique properties and its applications in the past few decades. Some of its properties, in particular the electrical resistance (ER) based self-sensing property of SMA, have not been fully studied. Electrical resistance of an SMA wire varies during its phase transformation. This variation is an inherent property of the SMA wire, although it is highly nonlinear with hysteresis. The relationship between the displacement and the electrical resistance of an SMA wire is deterministic and repeatable to some degree, therefore enabling the self-sensing ability of the SMA. The potential of this self-sensing ability has not received sufficient exploration so far, and even the previous studies in literature lack generality. This paper concerns the utilization of the self-sensing property of a spring-biased Nickel-Titanium (Nitinol) SMA actuator for two applications: ER feedback position control of an SMA actuator without a position sensor, and estimation of the opening of a SMA actuated valve. The use of the self-sensing property eliminates the need for a position sensor, therefore reducing the cost and size of an SMA actuator assembly. Two experimental apparatuses are fabricated to facilitate the two proposed applications, respectively. Based on open-loop testing results, the curve fitting technique is used to represent the nonlinear relationships between the displacement and the electrical resistance of the two SMA wire actuators. Using the mathematical models of the two SMA actuators, respectively, a proportional plus derivative controller is designed for control of the SMA wire actuator using only electrical resistance feedback. Consequently, the opening of the SMA actuated valve can be estimated without using an extra sensor.

• 한국수자원학회논문집
• /
• 제33권3호
• /
• pp.341-350
• /
• 2000

본 연구의 목적은 추계동역학적 상태·공간형태의 하도 저류함수모형을 개발하고 실시간 홍수예보를 위한 모형의 적용성을 검토하는데 있다. 팔당댐에서 인도교 지점에 이르는 하도구간을 개발된 모형의 적용 대상구간으로 설정하였으며, 1987∼1998년에 발생한 13개의 홍수사상을 선택하여 모형 매개변수 산정 및 적용성을 검토하였다. 그 결과 최적 매개변수는 각 홍수사상마다 다르지만, 현재 실무에서 사용하고 있는 매개변수를 사용한 유량예측은 비교적 합리적인 결과를 제시하였다. 또한 본 연구에서 개발한 추계동역학적 모형에 의한 유량예측 결과와 기존의 확정론적 모형에 의한 결과를 비교·검토한 결과 본 연구모형이 보다 정확한 결과를 제시하는 것으로 나타났다. 본 연구 대상지역의 예측가능시간을 분석한 결과 비교적 지류의 유입이 적은 홍수사상의 경우 5시간 정도까지는 정확한 하류단이 유량예측이 가능한 것을 판단된다.