품질향상을 위한 효과적인 공정관리체계는 기업의 생존에 있어서 매우 중요하다. 최근에는 제품의 수명과 관련된 신뢰성이 강조되면서, 신뢰성분포로 불리는 비정규분포하에서의 공정관리가 핵심과제로 여겨지고 있다. 특히 품질특성치가 비정규분포를 따를때, 정규가설에 기초한 공정관리기술을 사용한다면 심각한 오류가 초래될 수 있기 때문에, 비정규분포에서의 관리도와 신뢰성샘플링계획에 대한 중요성이 강조되고 있다. 본 연구의 목적은 비정규분포에서의 관리도와 신뢰성샘플링계획에 대한 최근연구를 조사하고, 보다 합리적이고 신뢰도 높은 공정분석에 대한 연구동향을 소개함으로써, 비정규분포하에서의 공정관리에 대한 발전적인 연구방향을 제시하는 것이다.
This study describes a hydraulic fluid property compensator under the various operating conditions. Because hydraulic fluid systems have much more excellent features than other control systems, they are used in many fields. However, the characteristics of hydraulic fluid are changed due to various operating conditions. This phenomenon is called uncertainty. Especially, bulk modulus is considered as the most dominant parameter in this study. In order to overcome the uncertainty ∞ control technique will be used for this study. Designed controller using the ∞ control technique, is adopted for the hydraulic fluid multistage double acting oil pressure cylinder. Repetition operation test gives from 5 to 8 percent errors in moving position.
The control chart is widely used statistical process control(SPC) tool that searches for assignable cause of variation and detects any change of process. Generally, ?맴詠? control chart and ?맴詠? are most frequently used. When the production run is short and
In this study, with the objects of 173 institutions of university and research institutions, investigation was carried out through visit investigation ar d questionnaire investigation. Frequency and severity of occurrences was acquired mainly through universities and research institutions which have reported occurrences of accidents to the Ministry of Education, Science, and Technology. Quantitative danger evaluation was conducted through frequency and strength of occurrences. Case study was carried out by selecting bio science laboratory of university and as the result of this study, degree of danger among the inspection objects of bio science laboratories, laboratory work place was evaluated as the most dangerous with the scores of 155.00 and as the result of average danger level, compression gas cylinder was evaluated as the most dangerous with the scores of 6.4000.
In this study, with the objects of 173 institutions of university and research institutions, investigation was carried out through visit investigation and questionnaire investigation. Frequency and strength of occurrences was acquired mainly through universities and research institutions which have reported occurrences of accidents to the Ministry of Education, Science, and Technology. Quantitative danger evaluation was conducted through frequency and strength of occurrences. Case study was carried out by selecting bio science laboratory of university and as the result of this study, degree of danger among the inspection objects of bio science laboratories, laboratory work place was evaluated as the most dangerous with the scores of 155.00 and as the result of average danger level, compression gas cylinder was evaluated as the most dangerous with the scores of 6.4000.
Real-time hybrid testing technique (RT-HYTT) is a structural dynamic testing method that the numerical calculation of the equations of motion of a structure and the experimental measurement of the reaction forces resulting from the application of this motion to the numerical structure are simultaneously implemented in real time. In this paper, structural control performance of the magneto-rheological (MR) damper installed in a real-scaled 5 story building is experimentally evaluated through real-time hybrid test method. In this method, a numerical substructure is based on a structural model identified from the forced vibration testing results of a real-story building, and an MR damper that is used as an experimental substructure is physically tested with a universal testing machine (UTM). In the test, load cell on the UTM measure the force necessary to attain the required story displacement and these structural reaction forces are returned to the computer for use in next time step calculation of a numerical structural model. Test results show that the higher level of control force generated by the Mr damper causes the lower level of controlled response of a structure.
A wax-typed pheromone dispenser has been developed and applied to control outbreak of the oriental fruit moth, Grapholita molesta, in apple orchard. To optimize its application technique, this study analyzed effect of different amounts of the pheromone dispenser on mating disruption (‘MD’) of G. molesta. Different pheromone dispenser amounts significantly influenced the MD effect assessed by cumulative male adult catches monitored respectively by sticky delta trap and food trap, and resulted in differential damage on host plants. In a field test during entire growing season, a standard amount (120 g per 0.117 ㏊) of wax-typed pheromone dispenser was proved to be effective to suppress outbreak of G. molesta adults and to prevent host plant damage as much as a current commercial MD product (Isomate<SUP>Ⓡ</SUP>). This study also demonstrated an effectiveness of deployment of food trap barriers around MD-treated area to prevent immigration of mated females from outside untreated areas. These results indicate that the wax-typed pheromone dispenser can be applied to control field G. molesta populations and its co-application with food trap barriers would be optimal to maximize MD efficacy.
아무리 좋은 그래픽과 뛰어난 엔진 성능과, 독창적인 아이디어, 그리고 마케팅 능력을 가진 게임이라 할지라도 게임이 밸런스가 잡히지 않은 게임이라면 아무런 소용이 없다. 이를 알고 있는 게임 개발자들은 밸런스에 많은 노력을 기울이지만 명확한 기준 없이 수많은 테스트를 통해 결과를 얻는다. 본 논문에서는 기존의 테스트를 통한 게임의 밸런스를 수정하는 방법을 개량하여 시간과 자원을 아낄 수 있는 방안에 대해 고찰하였다. 특히 MMORPG 게임에서 유저들이 가장 많이 사용하게 되는 스킬을 가지고 밸런스 방법에 대해 접근 하며 각각의 가지고 있는 특징들을 가치로 부여함으로써 스킬의 파라미터를 조율하고 이를 통해 캐릭터들 간의 밸런스도 좀 더 효과적으로 할 수 있도록 유도하는 방법론에 대해 제안하고자 한다. 본 연구 결과를 활용하면 객관적인 자료를 토대로 효율적이고 체계적인 밸런스가 가능하다.
온라인 게임을 비롯한 많은 인터넷 매체 중에 사회적 통제를 요구하는 유해한 동영상이 아무른 재제 없이 무분별하게 배포됨으로서 심각한 역기능이 발생되고 있다. 이는 청소년의 정신 건강에 큰 문제를 발생하게 되면 사회적, 제도적 규제가 절실하다. 본 논문에서는 영상이 가지는 컬러 공간 정보를 이용하여 동영상의 유해성을 판별할 수 있는 대표 프레임 선정 기법을 제안한다. 이 기법을 기존의 히스토그램 정보를 이용한 유해한 대표 프레임 선정 기법과 비교하여 매우 효과적임을 증명하였다. 본 연구 결과는 유해 동영상을 판별하는 도구에 적용하면 매우 효과적일 것이다.
보의 고유진동수는 진동해석 뿐만 아니라 구조물의 동적특성을 파악하는데 중요한 역할을 한다 보의 단면이 불연속적으로 변하는 계단형 보의 고유진동수 해석은 복잡하다. 이런 계단형 보의 진동해석은 Rayleigh-Ritz법, FEM 등과 같은 근사해석법이 흔히 사용되는데 이들 해석의 정확성은 분할요소의 수, 계산의 반복수, 가정처짐곡선의 형상에 따라 좌우된다. 본 연구에서는 계단형 외팔보의 등가보 변환 방법을 이용한 기본고유진동수의 근사해석방법을 제시하고자 하였으며 여러 예제에 대하여 제안방법과 유한요소해석 결과를 비교하여 그 적용성과 신뢰성을 검증하였다.
현재 도시부 도로에 대한 서비스 수준 평가는 통행속도, 지체 등과 같은 정량적인 부분만을 고려하였다. 하지만 도시부 도로를 이용하는 운전자들은 정량적인 부분이외에도 도로의 청결, 타운전자의 법규위반 등의 정성적인 측면에서도 영향을 받고 있는 것이 현실이다. 이에 본 연구에서는 정량적인 부분과 정성적인 부분을 함께 고려하여 평가지표를 도출하고, 서비스 측면의 개선사항 도출시 주로 경영분야에서 사용되고 있는 Importance-Performance Analysis (IPA) 기법을 변형하여 사용하였다. 본 연구에서 제안된 변형된 IPA 분석기법은 분석대상 및 항목간 상대적 수준을 반영하여 서비스 수준이 평가될 수 있도록 구성되어 있다. 사례분석 지역으로 서울시 강남 3개구, 강북 3개구를 선정하여 도시부 도로의 서비스 질 평가가 수행되었으며, 변형된 IPA 평가를 토대로 도로 서비스 질 향상을 위한 지역별 개선항목을 도출하였다.
A new cost-effective atomic layer deposition (ALD) technique, known as Proximity-Scan ALD (PS-ALD) was developed and its benefits were demonstrated by depositing Al2O3 and HfO2 thin films using TMA and TEMAHf, respectively, as precursors. The system is consisted of two separate injectors for precursors and reactants that are placed near a heated substrate at a proximity of less than 1 cm. The bell-shaped injector chamber separated but close to the substrate forms a local chamber, maintaining higher pressure compared to the rest of chamber. Therefore, a system configuration with a rotating substrate gives the typical sequential deposition process of ALD under a continuous source flow without the need for gas switching. As the pressure required for the deposition is achieved in a small local volume, the need for an expensive metal organic (MO) source is reduced by a factor of approximately 100 concerning the volume ratio of local to total chambers. Under an optimized deposition condition, the deposition rates of Al2O3 and HfO2 were 1.3 Å/cycle and 0.75 Å/cycle, respectively, with dielectric constants of 9.4 and 23. A relatively short cycle time (5~10 sec) due to the lack of the time-consuming "purging and pumping" process and the capability of multi-wafer processing of the proposed technology offer a very high through-put in addition to a lower cost.
National Education Information System (NEIS) is an ambitious reform project that can improve the competitiveness and performance of education field and to link administrational work of between schools and their senior administration offices via internet. NEIS is introduced to lighten the teachers' overburden, to standardize the work process and to bring better quality education to each classroom and make it possible for those involved in education to resolve any related educational problem on line. This paper aims to construct a hierarchy model consisting of key factors such as technological and administrative factors for the effective use of NEIS and to evaluate the relative importance among key factors using fuzzy AHP technique included fuzzy concepts. Eventually, the analysis results can be utilized to develop the future improvement strategy of NEIS and to satisfy the users.
Hedera helix 11계통, Hedera rhombea 3계통, Fatshedera lizei 1계통, 그리고 Fatsia japonica 1계 통을 수집하였다. RAPD primer 10개를 이용하여 수 집된 3속의 재료들의 유전적 다양성을 측정하였다. 3 속을 재료로 사용하여 밴드간 96.9%의 높은 다형성을 보였다. 총 97개의 RAPD 밴드를 이진화하여 UPGMA 방법을 이용하여 계통도를 작성하였다. Hedera helix 계통들은 모두 1개의 그룹에 속하였으며 8계통의 유전 적 거리는 극도로 적었으며 나머지 3계통 역시 유전적 으로 가까웠다. 하지만 형태적으로는 높은 다형성을 보 였다. 따라서 수집된 유전자원을 이용한 돌연변이체 개 발이 가능성이 있는 방법으로 제시되었다. Fatsia japonica는 유전적으로 관계성이 적어 다른 종들과 평 균 0.63의 유전적 거리를 보였다. Hedera helix와 Fatsia japonica 속간 교배를 통하여 개발된 Fatshedera lizei는 Hedera rhombea 계통들과 함께 계통도에서 위치하였다.
In the present study, electrospun PAN precursor webs and the stabilized and carbonized nanofiber webs processed under different heat-treatment conditions were characterized by means of weight loss measurement, elemental analysis, scanning electron microscopy (SEM), attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC), thermogravimentric analysis (TGA), and X-ray diffraction (XRD) analysis. The result indicated that stabilization and carbonization processes with different temperatures and heating rates significantly influenced the chemical and morphological characteristics as well as the thermal properties of the stabilized and then subsequently carbonized nanofiber webs from PAN precursor webs. It was noted that the filament diameter and the carbon content of a carbonized nanofiber web as well as its weight change may be effectively monitored by controlling both stabilization and carbonization processes.
초지조성과 개량에서 겉뿌림은 중요한 방법 중의 하나이다. 오늘날 겉뿌림 초지조성에서 종자피복기술은 관심이 높아지고 있다. 따라서 본 시험은 산지초지에서 겉뿌림조성시 목초의 출현율과 정착율을 높이기 위해 화본과목초종자의 피복기술을 개발하기 위하여 실시하였다. 종자 펠렛팅은 피복시간을 단축하고 단위시간당 피복량을 증가시킴으로서 종자피복의 새로운 기술로 평가되었다. 펠렛종자의 건조시간을 단축하고 건조온도를 낮춤으로서 화본과 목초종자의 발아세와 발아율이 증가하
This study examined the effects of hold-relax with agonist contraction (HR-AC) on the symptoms of delayed onset muscle soreness (DOMS) induced by intensive eccentric exercise of the non-dominant biceps brachii. Ten men (mean age=26.7 yrs, mean height=172.1 cm, mean weight=66.2 kg) and ten women (mean age=27.4 yrs, mean height=165.9 cm, mean weight=60.7 kg) who had not participated in a regular exercise program for the upper extremities in the previous six months were randomly assigned to one of two experimental groups: the HR-AC group, or the control group. We measured joint range of motion (ROM), maximal voluntary isometric contraction (MVIC), and muscle soreness before eccentric exercise, and 24, 48, and 72 hours after eccentric exercise. The subjects in the HR-AC group received the HR-AC technique in the non-dominant biceps brachii. The HR-AC technique was applied 24 and 48 hours after eccentric exercise. There was no significant difference between the HR-AC and the control group. However, the HR-AC group, compared to the control group, had a significant difference between the time points of the various parameters. Increased ROM (p<.05), decreased muscle soreness (p<.05), and reduced MVIC (p<.05) were found in the HR-AC group after 72 hours. Decreased ROM (p<.05) and MVIC (p<.05), and increased muscle soreness (p<.05) were observed in the control group. These findings suggest that the HR-AC technique effectively reduces muscle soreness and increases ROM 72 hours after eccentric exercise.