선박 및 플랜트의 배관은 제작부터 설치까지 일련의 과정을 모두 현장에서 하는 것이 아닌, 외부의 공장 또는 숍으로부터 배관의 제일 작은 요소인 스풀 배관을 제작하고, 이를 작업현장 또는 현장 근처의 공장에서 모듈화 또는 가설치 작업 및 현장에서 직접 설치작업을 통해 제작이 된다. 이 과정에서 스풀은 3D CAD를 기반으로 하는 것이 아닌 2D 도면을 기반으로 하기 때문에, 작업공간을 고려하지 못할 수 있다. 이러한 이유로 실제 설치작업 시 작업공간의 방해로 인한 공기의 지연을 발생 시킬 수 있다. 본 논문은 이러한 스풀 배관의 설치 시 또는 운용 및 유지보수 시에 생길 수 있는 외부 구조물과의 스풀 위치에 관하여, 스풀 위치가 외부 구조물로부터 방해를 받지 않도록 하기 위한 방법으로 유전 알고리즘을 적용하여 스풀 위치를 결정하는 방법에 대해 제시하고자 한다.

This study is the sequel of a companion paper (I. Algorithm) for assessment of the seismic performance evaluation of structure using ground motions selected by the proposed algorithm. To evaluate the effect of the correlation structures of selected ground motions on the seismic responses of a structure, three sets of ground motions are selected with and without consideration of the correlation structure. Nonlinear response history analyses of a 20-story reinforced concrete frame are conducted using the three sets of ground motions. This study shows that the seismic responses of the frames vary according to ground motion selection and correlation structures.

It is important to select an accurate set of ground motions when conducting linear and nonlinear response history analyses of structures. This study proposes a method for selecting ground motions from a ground motion library with response spectra that match the target response spectrum mean, variance and correlation structures. This study also has addressed the determination of an appropriate value for the weight factor of a correlation structure. The proposed method is conceptually simple and straightforward, and does not involve a simulation algorithm. In this method, a desired number of ground motions are sequentially selected from first to last. The proposed method can be also used for selecting ground motions with response spectra that match the conditional spectrum. The accuracy and efficiency of the proposed procedure are verified with numerical examples.

This paper is concerned with the single vendor single buyer integrated production inventory problem. To make this problem more practical, space restriction and lead time proportional to lot size are considered. Since the space for the inventory is limited in most practical inventory system, the space restriction for the inventory of a vendor and a buyer is considered. As product’s quantity to be manufactured by the vendor is increased, the lead time for the order is usually increased. Therefore, lead time for the product is proportional to the order quantity by the buyer. Demand is assumed to be stochastic and the continuous review inventory policy is used by the buyer. If the buyer places an order, then the vendor will start to manufacture products and the products will be transferred to the buyer with equal shipments many times. The mathematical formulation with space restriction for the inventory of a vendor and a buyer is suggested in this paper. This problem is constrained nonlinear integer programming problem. Order quantity, reorder points for the buyer, and the number of shipments are required to be determined. A Lagrangian relaxation approach, a popular solution method for constrained problem, is developed to find lower bound of this problem. Since a Lagrangian relaxation approach cannot guarantee the feasible solution, the solution method based on the Lagrangian relaxation approach is proposed to provide with a good feasible solution. Total costs by the proposed method are pretty close to those by the Lagrangian relaxation approach. Sensitivity analysis for space restriction for the vendor and the buyer is done to figure out the relationships between parameters.

This paper introduces the existence of purchase dependence that was identified during the analysis of inventory operations practice at a sales agency of dealing with spare parts for ship engines and generators. Purchase dependence is an important factor in designing an inventory replenishment policy. However, it has remained mostly unaddressed. Purchase dependence is different from demand dependence. Purchase dependence deals with the purchase behavior of customers, whereas demand dependence deals with the relationship between item-demands. In order to deal with purchase dependence in inventory operations practice, this paper proposes (Q, r) models with the consideration of purchase dependence. Through a computer simulation experiment, this paper compares performance of the proposed (Q, r) models to that of a (Q, r) model ignoring purchase dependence. The simulation experiment is conducted for two cases : a case of using a lost sale cost and a case of using a service level. For a case of using a lost sale cost, this paper calculates an order quantity, Q and a reorder point, r using the iterative procedure. However, for a case of using a service level, it is not an easy task to find Q and r. The complexity stems from the interactions among inventory replenishment policies for items. Thus, this paper considers the genetic algorithm (GA) as an optimization method. The simulation results demonstrates that the proposed (Q, r) models incur less inventory operations cost (satisfies better service levels) than a (Q, r) model ignoring purchase dependence. As a result, the simulation results supports that it is important to consider purchase dependence in the inventory operations practice.

The present study addresses the tea utensils and tea drinking methods seen in tomb mural paintings of Song, Liao, Jin, and Yuan, which were Koryo’s foreign exchange countries. The paintings illustrate the pointing tea method, which was popular during dynasty times. Tea utensils observed in the paintings include a tea mill, mill stone, and tea pestle necessary for making cake tea into powder. The tea stove and boiling bottle are depicted as being required to boil water. Some mural works vividly depict how a tea drinker pours hot water from a boiling bottle into a cup with a stand, mixes it with a tea spoon, and whisks tea powder for foaming with a tea whisk. The tea drinking method of the Southern race Han is also similarly described in the tomb mural paintings of Liao, Jin, and Yuan from Northern nomads. The distribution of tea culture had an enormous influence on the development of tea utensil manufacturing methods. The significance of this study is that these findings can be used as basic data to provide food culture insights into Koryo celadon tea utensils.

Purpose: The purpose of this study was to identify the difference in problem solving ability and learning flow by team based simulation learning depending on the level of metacognition of nursing students. Methods: This study was one group pre-posttest design. The subjects were 81 students enrolling in the simulation-based practice. Simulation learning included team based pre-discussion, taking a simulation and being debriefed during 4 weeks. Data were collected from May to June, 2015 using a structured questionnaire on metacognition, problem solving ability, and learning flow. Data were analyzed using SPSS win 20.0 program. Result: There were significant positive correlations between metacognition, problem solving ability, and learning flow. The student who had higher metacognition score than other group had scored problem solving ability and learning flow in pre and post program. Conclusion: These results suggest that metacognition has a positive effect on nursing students' learning outcomes. Therefore, it should be considered the metacognition in composing the team based simulation learning in nursing.

An eductor is an fluid transportation simplified device that generate relatively low pressure utilizing the kinetic energy of pressured fluid to provoke suction of another fluid, mix the two and discharge the mixture against a counter pressure. In this study, a parameter analysis was conducted to predict the eductor performance against various operating conditions.

본 연구에서는 선미형상을 고려한 조종성능을 심수역 뿐만 아니라 천수역에 대해서 수치 시뮬레이션을 통해 검토하였다. 선미형상을 나타내는 파라메터 중 Cwa를 미소(±2%)하게 변화시킴으로써 각 수역에서의 침로안정성, 선회 및 지그재그 성능이 어떤 변화를 보이고 그 경향이 어떻게 변화하는 지를 검토하였다. 선박의 조종성능 관점에서 흘수 대 수심의 비(=d/H)가 0.5 부근에서의 조종성에 큰 변화를 가져오는 중요 지점임을 알 수 있었고, 비대선(VLCC, 탱커 등)과 세장선(컨테이너)의 경우 선미형상의 변화에 따라 조종성능의 변화 정도가 많은 차이를 가질 수 있음을 알 수 있었다. 또한, Cwa를 감소(U형에 근접)시키면 선회운동에 있어서 advance 및 tactical diameter가 증가하고, 지그재그 운동에서는 track reach는 증가하지만 각 overshoot angle들은 감소한다. 이와 반대로, Cwa를 증가(V형에 근접)시키면 선회운동에 있어서 advance 및 tactical diameter는 감소, 지그재그 운동에서는 track reach는 감소, 각 overshoot angle 들은 증가함을 알 수 있었다.

뛰어난 단열성능을 가지는 폴리우레탄 폼(polyurethane foam, PUF)은 다양한 구조물에서 다른 재료들과 함께 사용되고 있다. 현재 LNG 운반선의 단열시스템에는 유리섬유로 강화된 폴리우레탄 폼(reinforced-polyurethane foam, R-PUF)이 사용되고 있으며, 이는 단열재 역할뿐만 아니라 슬로싱 하중을 포함한 다양한 압축하중에 대한 구조부재 기능을 수행하고 있다. 폴리우레탄 폼은 혼합과 발포를 통해 제작되는 다공성 재료이기 때문에, 본 연구에서는 기공체적비율을 통해 재료의 거동을 모사할 수 있는 Gurson damage model을 사용하여 폴리우레탄 폼의 비선형 압축거동을 모사하였으며, 폴리우레탄 폼의 기계적 성질에 영향을 미치는 영향변수로서 기공체적비율에 의존적으로 알려져 있는 밀도를 설정하였다.

본 논문에서는 커코프 판이론과 폰-칼만 비선형 변형율-변위 관계를 이용하여 서형화된 좌굴해석을 수행하였다. 평면응력과 좌굴문제에서 영률과 두께에 관한 설계민감도식을 유도하였고, 고유치를 최대화하면서 컴플라이언스를 최소화하는 위상최적설계 기법을 정식화하였다. 좌굴해석에서의 프리스트레스를 이용하여 판 좌굴문제에 적용할 수 있는 위상최적설계 기법을 개발하였다. 폰-칼만 비선형 변형률을 사용하여 좌굴문제의 응력행렬을 구성하는데 프리스트레스가 필요하므로 면외로의 운동을 도입하였다. 위상최적설계를 위하여 정규재료밀도를 설계변수로 하고, 목적함수는 최소 컴플라이언스와 최대 고유진동수로 하였으며 제한조건은 허용되는 재료량이다. 여러 수치예제를 통하여 개발된 설계민감도 해석법은 유한차분 민감도와 비교하여 매우 정확한 값을 가지고, 위상최적설계는 물리적으로 의미있는 결과를 제공함을 확인하였다.

원전해체시장이 본격적으로 도래함에 따라 그에 따른 기술연구가 부각되고 있다. 그러한 기술 중 방사선 제염은 직접적인 원전해체 과정 중 가장 초반에 행해지는 작업으로 현장 근로자의 안전확보 및 폐기물 양 감소를 위해 수행되는 중요한 작업 이다. 제염을 통해 폐기물 표면에 존재하는 방사선 물질을 제거하게 되는데 해체에 적용되는 제염기술은 보다 강한 매개체 를 사용하거나 개선된 설비를 활용하여 표면층 제거 정도가 일반적인 제염보다 훨씬 크다. 따라서 제염 계획 수립시 다양 한 관점에서 분석 방법이 필요하다. 본 연구에서는 제염기술 선정을 위해 고려해야 할 요인을 설명하였으며, 대표적인 제염 기술 사례 분석을 통해 실제 기술 수행을 위해 원전 설비 내 제염 아이템 선정 및 제염 장비 활용을 위해 검토해야 할 사항 을 제시하였다.

The single vendor single buyer integrated production inventory problem with lead time proportional to lot size and space restriction is studied. Demand is assumed to be stochastic and the continuous review inventory policy is used for the buyer. If the buyer places an order with lots of products, then the vendor will produce lots of products and the products will be transferred to the buyer with equal shipments many times. Mathematical model for this problem is defined and a Lagrangian relaxation approach is developed.

This study is on the alcohol beverage utensils represented on the Chinese tomb mural paintings of Song, Liao, Jin, and Yuan those countries had foreign exchange with Koryo Dynasty. These mural paintings are distributed in the areas such as Hebei, Henan, Inner mongolia, Shanxi, Shaanxi, Peijing. etc. The Alcohol beverage vessels were classified mainly into storage vessel, pouring vessel, drinking vessel and ladles according to the purpose. The storage vessels of Song, Liao and Jin were called Jiuping, Jingping, Jiuzun as well as Meiping. Pouring vessels are basically one set of Zhuzi, Wenwan and Jiuzhu, or Zhuhu and Zhuwan. On the mural paintings of Yuan Dynasty, Meiping as storage vessels disappear, and a variety of shapes of pouring vessels such as Mayu and Yuhuchunping appear. This trend indirectly indicates the new arrival of distilled liquor, which seems to have affected transition of the alcohol beverage utensils.

본 연구의 목적은 우리나라의 주요 석재 생산지인 익산시에 소재하는 5개 지구의 폐채석장을 대상으로 관광, 휴양, 산업 등의 시설로 개발하는 방안을 모색하기 위한 것이다. 먼저 익산시의 제반 여건, 법규, 개발계획, 현장여건을 분석한 결과를 조합하여 폐채석장 개발과 관련된 SWOT분석을 하고 대응전략을 구상하였다. 그리고 모든 분석과 대응전략을 기반으로 하여 대상 지구별로 적절한 개발유형을 도출하였다. 도출된 지구별 개발유형은 낭산1지구는 물을 활용한 문화/ 레포츠단지, 낭산3지구는 빛을 활용한 음악/문화단지, 낭산4지구는 꽃을 활용한 자연/휴양단지, 함열1지구는 나무를 활 용한 자연복구 및 생태공원, 용기지구는 돌을 활용한 저장/물류단지이다. 대상 지구별로 아이템의 개발 가능성, 개발효 과, 개발과 관련된 문제점 등을 제시하였다.

PURPOSES: Recently, many local governments have applied chicanes for traffic calming to ensure environment-friendly comfortable and safe roads. However, the geometry of a chicane is designed for speed reduction using a curved portion. This study aims to improve the road geometry conditions of chicanes for reducing carbon emissions and maintaining appropriate driving speeds by considering the relationship between road geometry and carbon emissions. METHODS: This study was conducted as follows. First, carbon emissions corresponding to changing acceleration of vehicles were studied. Second, vehicle acceleration caused by the relationship between the curve radius and the straight length was studied. Accordingly, desirable conditions of curve radius and length of the straight section for reducing carbon emissions were proposed. RESULTS: The existing literature on chicanes present the minimum value of stagger length and path angle in the primary variable condition. This study suggests the maximum values of the curve radius and length of straight section in the primary variable condition. Therefore, if a vehicle’s speed at a chicane is 30 km/h, this study suggests a curve radius of up to 24 m. In addition, if the vehicle’s speed is 24 km/h, this study suggests a length of straight section of up to 6.6 m. These are the geometric conditions for considering the control of acceleration to the vehicle’s maximum speed. CONCLUSIONS: This paper proposes an application of geometric conditions to reduce carbon emissions and maintain appropriate speeds of vehicles through a combination of curve radius and length of straight section.