기성콘크리트 부재의 현장생산 리스크 평가를 위한 체크리스트 개발

임지영 ( Lim¸ Jeeyoung ),정희웅 ( Jeong¸ Hee Woong ),김대영 ( Kim¸ Dae Young ) 한국건축시공학회 2021 한국건축시공학회지 Vol.21 No.5

기성콘크리트 부재를 현장 생산하는 경우 공장생산보다 약 14.5-39.4%의 원가가 절감되는 것으로 이전 연구에서 확인되었다. 특히, PC공장 관계자의 인터뷰를 통해, 실제 공장주는 생산원가의 20% 이상의 이윤을 얻지 못하면 공장관리 간접비를 cover하지 못해 계약을 하지 않는 것으로 확인되었다. 그리고 동등한 조건에서 기성콘크리트 부재를 현장에서 생산한다면 공장생산 대비 동등 이상의 품질이 확보된다. 이 연구들에 따르면 원가와 품질 측면에 유리하므로 기성콘크리트 부재는 현장에서 생산하여야 한다. 그러나 주어진 공기뿐 아니라 현장생산을 위한 여러 가지 제약조건으로 모든 물량을 현장생산하기 어렵다. 그 이유는 현장생산은 프로젝트 관리 과정에서 발생할 수 있는 리스크로 인하여 기피하기 때문이다. 그러나 기성콘크리트 부재의 현장생산 수행 전 리스크 요인을 분석하고 그에 대응한다면 현장생산 기회를 높일 수 있다. 따라서 본 연구는 기성콘크리트 부재의 현장생산 리스크 평가를 위한 체크리스트를 개발한다. 체크리스트를 1개의 사례현장에 적용하여 리스크 요인을 쉽고 빠르게 평가할 수 있다는 것을 검증하였다. 그 결과 건폐율이 높은 현장의 경우 생산 및 야적을 위한 가용면적을 확보하기 어려워 리스크가 큰 현장으로 분류되는 것으로 분석되었다. 개발된 리스크 평가 체크리스트는 현장생산의 리스크요인을 효율적으로 평가하며, 프로젝트 수행 시 수시로 변경되는 리스크요인을 쉽고 빠르게 판단하여 상황에 따라 대처가 가능하다. In previous studies, it was confirmed that through the in-situ production of precast concrete members, costs could be reduced by 14.5-39.4% compared to in-plant production. In particular, it was confirmed that the factory owner did not make a contract if it did not earn more than 20% of the production cost. If precast concrete members are produced in-situ under the same conditions, the quality equivalent to that of factory production can be secured. As it is advantageous in terms of cost and quality, precast concrete members must be produced in-situ. However, it is difficult to produce all quantities in-situ due to time and various other constraints. This is because in-situ production is avoided due to anticipated risks during the project management process. However, if the risk factors are analyzed before performing in-situ production of precast concrete members, it will increase the opportunity for in-situ production. Therefore, this study develops a checklist for evaluating the risk of in-situ production of precast concrete members. By applying the checklist to one case site, it was verified that risk factors can be evaluated easily and quickly. As a result, it was analyzed that sites with a high building coverage ratio are classified as high-risk sites because it is difficult to secure usable area for production and storage. The developed checklist efficiently evaluates the risk factors of in-site production, and makes it possible for the operator to determine the risk factors, which can change frequently during project execution, and respond according to the situation.

AN EXPERIMENTAL STUDY FOR QUALITY ASSURANCE OF FREE-FORM CONCRETE PANELS PRODUCED BY CNC MACHINE

LIM, Jeeyoung,KIM, Do Yeong,KIM, Sunkuk Vilnius Gediminas Technical University 2018 Journal of Civil Engineering and Management Vol.24 No.2

<P>Various studies have been conducted to construct free-form buildings, but it still takes a lot of labor, cost, and time to assure the accuracy of designed shapes. In particular, molds for the production of free-form concrete panels (FCPs) are putting enormous burdens on productivity and cost. To produce FCPs economically, a computerized numeric control (CNC) machine that produces phase change material (PCM) molds for persistent use was developed in this study. The technology using CNC machine can produce precisely free-form molds and panels in a short time compared to the manual method. However, in order to commercialize this technology, it is necessary to verify the shape error of the FCPs. Therefore, the purpose of this paper is an experimental study for securing FCP quality produced by a CNC machine. The results of this study will be used to mass-produce uniform quality of FCPs without depending on the skill and workmanship of the labo.</P>

Trend of Domestic Fig Industry and its Implications

Jeeyoung Lim,Jihye You,Junhong Park,Junghoon Moon 한국농식품정보과학회 2018 Agribusiness and Information Management Vol.10 No.1

Fig is a fruit of which the flesh is very sweet, and it is a tree which has been grown for fruit in Korea since long time ago. However, since the flesh of fig tends to be easily softened, commercial cultivation of this fruit began later than that of other fruit trees grown for profit, however, the cultivation and demand of fig tend to be increased steadily due to the development of technology for storage and distribution since the 2000s. In addition, as the domestic dining culture is getting diversified, the dishes cooked by using fig as a food material are introduced through diverse foods including dessert, and it is possible to intake fig in diverse ways, but not through the traditional processed food. Therefore, it is necessary to establish a measure of expanding the consumption of fig as a processed food, and it will be possible to overcome the limitation of short storage period, while securing the competitiveness of the fig industry. In this research, we have studied the history of domestic fig cultivation, current status of it and status of processed foods through related documents and materials, and the characteristics of the consumers who purchase figs. Fig is a traditional fruit, however, we could find out the fact that the consumers tend not to recognize it as a traditional one. Therefore, if we could add fig to various processed foods utilizing its sweet taste, rather than increasing the consumption of fresh fruits, it may increase the consumption of it.

A SOLUTION OF SUBORDINATE VERTICES FOR QUALITY CONNECTIONS OF EXTERNAL FREE-FORM CONCRETE PANELS

Lim, Jeeyoung,Son, Seunghyun,Yeong Kim, Do,Fitriani, Heni,Kim, Sunkuk Vilnius Gediminas Technical University 2018 Journal of Civil Engineering and Management Vol.24 No.5

<P>3D-designs of free-form buildings are developed using a computer due to difficulty of shape implementation. When producing free-form concrete panel (FCP) using materials such as GFRC (glass fiber reinforced concrete), engineers or manufacturers should precisely calculate the offset value or geometry of each member at the junction point of three or more FCPs before it is constructed. However, it is difficult to calculate offset geometry easily and quickly, and no research has been conducted on this topic. Therefore, the objective of this paper is to develop a solution of subordinate vertices for quality connections of external free-form concrete panels. The developed mathematical solutions practically support the production of FCPs with precise installation to ensure aesthetic quality of the building. This paper academically contributes to the automatic creation of joint details of FCPs implemented by BIM.</P>

Trend of Domestic Fig Industry and its Implications

Lim, Jeeyoung,You, Jihye,Park, Junhong,Moon, Junghoon Korean Society of Food and Agricultural Informatio 2018 Agribusiness and Information Management Vol.10 No.1

Fig is a fruit of which the flesh is very sweet, and it is a tree which has been grown for fruit in Korea since long time ago. However, since the flesh of fig tends to be easily softened, commercial cultivation of this fruit began later than that of other fruit trees grown for profit, however, the cultivation and demand of fig tend to be increased steadily due to the development of technology for storage and distribution since the 2000s. In addition, as the domestic dining culture is getting diversified, the dishes cooked by using fig as a food material are introduced through diverse foods including dessert, and it is possible to intake fig in diverse ways, but not through the traditional processed food. Therefore, it is necessary to establish a measure of expanding the consumption of fig as a processed food, and it will be possible to overcome the limitation of short storage period, while securing the competitiveness of the fig industry. In this research, we have studied the history of domestic fig cultivation, current status of it and status of processed foods through related documents and materials, and the characteristics of the consumers who purchase figs. Fig is a traditional fruit, however, we could find out the fact that the consumers tend not to recognize it as a traditional one. Therefore, if we could add fig to various processed foods utilizing its sweet taste, rather than increasing the consumption of fresh fruits, it may increase the consumption of it.

BIM 기반 형상코드를 이용한 내력벽 철근길이 자동 산정 기초 연구

임지영 ( Lim Jeeyoung ),김선국 ( Kim Sunkuk ) 한국건축시공학회 2023 한국건축시공학회 학술발표대회 논문집 Vol.23 No.1

Reinforced concrete structures require large amounts of concrete and rebar in the construction stage. Rebar is a major resource for reinforced concrete structures, and generates more CO₂ per unit weight than other materials. To solve this problem, it was confirmed that the cutting waste can be close to zero when the special length of the rebar is calculated in the drawing created after structural design. However, a system for automatically calculating the length of reinforcing bars to efficiently calculate the total amount of reinforcing bars has not been established. Therefore, the objective of this study is a basic study of automatic rebar length estimate algorithm of bearing wall by using BIM-based shape codes built in Revit. The bearing wall rebar can be automatically derived using the developed model. Furthermore, through applying the developed model to the construction field, it will greatly contribute to reducing greenhouse gas emissions by reducing rebar cutting waste.

대형물류센터 PC부재 양중을 위한 크레인 궤적거리 산정 기초 연구

임지영 ( Lim Jeeyoung ),오진혁 ( Oh Jinhyuk ),김선국 ( Kim Sunkuk ) 한국건축시공학회 2023 한국건축시공학회 학술발표대회 논문집 Vol.23 No.1

As large logistics buildings have high floor heights and long spans, these buildings are designed as PC structures, and large cranes are used to lift PC members. PC erection planning can generally cause errors depending on the field engineer’s experience. To solve this problem, a basic analysis method is needed to establish a systematic PC member erection plan. Crane work can be minimized if the trajectory is easily and quickly calculated according to the location of the crane and applied to the site. Therefore, the objective of this study is a basic study of crane trajectory distance calculation for sustainable PC members erection of large logistic building. In this study, a crawler crane commonly used for lifting PC members is limited. The trajectory distance for the PC erection plan was automatically calculated using the algorithm.

적대감 및 언어적 공격행동수준에 따른 네 집단 간의 비합리적 신념, 분노사고 및 삶의 만족도의 차이

임지영(Jeeyoung Lim) 한국콘텐츠학회 2015 한국콘텐츠학회논문지 Vol.15 No.2

본 연구는 남자 중학생들을 대상으로 공격성 요인과 삶의 만족도 간의 관계를 검증하고, 적대감과 언어적 공격행동의 수준에 따른 네 집단 간에, 특히 내현적, 외현적 적대감 집단 간에 비합리적 신념, 자동적 사고인 일차적 및 이차적 분노사고, 삶의 만족도에 차이가 있는 지를 알아보기 위해 수행되었다. 충남지역 남자 중학생 268명을 대상으로 하였다. 분석결과는 다음과 같다. 첫째, 공격성 요인 중 적대감이 삶의 만족도와 가장 큰 부적 상관을 보였고, 적대감을 통제한 후에는 언어적 공격행동이 정적 상관을 보였다. 단계적 회귀분석 결과, 적대감은 삶의 만족도를 부적으로, 언어적 공격행동은 정적으로 예언하였다. 둘째, 비합리적 신념, 일차적 분노사고, 이차적 분노사고의 요인들은 삶의 만족도와 부적 상관을 보였다. 셋째, 내현적 적대감 집단은 외현적 적대감 집단에 비해 자기비하, 친밀한 관계에서 경험하는 무시와 실망감, 무력감 요인의 점수가 높은 반면, 외현적 적대감 집단은 내현적 적대감 집단보다 타인비난/보복 요인의 점수가 높았다. 삶의 만족도는 내현적 적대감 집단이 다른 집단보다 낮았다. 이런 결과를 바탕으로 청소년의 적응을 돕기 위한 치료적 개입에 대한 함의와 후속연구를 위한 제언이 논의되었다. This study investigated the relationships between factors of aggression and satisfaction with life and the differences of irrational belief, primary·secondary anger thought, and satisfaction with life among four groups classified based on the levels of hostility and verbal aggression. 268 middle school boys in Chungnam areas served as subjects. The results showed that hostility showed the most negative correlation with satisfaction with life. Stepwise regression analyses showed that hostility negatively predicted satisfaction with life, whereas verbal aggression positively predicted satisfaction with life. Factors of irrational belief, primary/secondary anger thought were negatively correlated with satisfaction with life. Analyses of variances revealed that covert hostility group showed higher scores on self-depreciation, disregard and disappointment in intimate relationship situation, hopelessness, whereas overt hostility group showed higher scores on derogation of others/revenge. In addition, covert hostility group showed lower scores on satisfaction with life than other groups. Finally, limitations of this study and suggestions for future study were discussed.

거더교 상판 콘크리트 타설용 거푸집 개발 및 경제성 분석

임지영 ( Jeeyoung Lim ),김선국 ( Sunkuk Kim ),손기영 ( Kiyoung Son ) 한국건축시공학회 2016 한국건축시공학회지 Vol.16 No.3

국내 철도 및 도로 교량의 대표적 상부구조 형식인 철제 (steel box 또는 H-형강) 거더교와 PSC (Pre-Stressed Concrete) 거더교는 현재 가장 많이 시공되는 교량형식으로 전체 교량의 75%, 시공 금액의 80%를 차지하고 있다. 거더교 상판 콘크리트 타설을 위한 거푸집 공사는 여러 가지 시공의 어려움 때문에 다양한 공법이 개발 및 적용되었다. 그러나 재료 손실 및 인건비 상승으로 인한 원가 상승, 미숙련공에 의한 품질 저하, 복잡한 시공방법으로 인한 공기 증가, 생산성 저하, 고소작업으로 인한 안전사고 발생, 큰 부재로 인한 운송성 저하, 재료 특성으로 인한 유지관리비 증가 등 여러 가지 문제가 부분적으로 해결되지 않았다. 이를 해결하기 위하여 기존 공법을 대체할 수 있는 공법이 필요하다. 따라서 본 연구는 거더교 상판 콘크리트 타설용 시스템 거푸집 (Purlin Hanging System Form)의 개발연구 및 경제성 분석을 목적으로 한다. 본 연구를 통해 Purlin Hanging System Form이 기존 공법에 비해 60%의 원가절감, 80%의 공기단축 효과가 있음을 확인하였다. In the case of South Korea, steel girder bridge (steel box or H-steel) and PSC (Pre-Stressed Concrete) girder bridge are the representative upper structures of railroad and road bridges. These structures account for 75% of the total bridge constructions and 80% of the total construction cost. Since the form work for concreting bridge slab is difficult, various construction methods developed and applied. However, several problems in those methods did not solve partially, including cost increase by material loss and rise of labor costs, quality deterioration by unskilled workers, increased construction time by complicated method, reduced productivity, safety accident by high place work, difficult transportation by big member, and rise of maintenance cost by material characteristic. Alternative method is needed to solve problems of as-is methods. Therefore, the purpose of this study is development of the purlin hanging system form for the girder bridge slab and its economic analysis. Through the findings of this study, it was verified that the purlin hanging system form is possible 60% reduction in cost and 80% reduction in time as comparison with conventional method.

비정형 콘크리트 부재의 현장생산에 대한 리스크 식별

임지영(Lim, Jeeyoung),손승현(Son, Seunghyun),김도영(Kim, Doyeong),김선국(Kim, Sunkuk) 대한건축학회 2017 대한건축학회 학술발표대회 논문집 Vol.37 No.1