혁신금융 유입에 영향을 미치는 산업별 내생적 특성비교 및 신경망분석을 통한 예측성과 분석

서승범,오동찬,이유정 대한산업공학회 2023 대한산업공학회 춘계학술대회논문집 Vol.2023 No.5

전략적 일탈이 연구개발비 행태에 미치는 영향

서승범,이창섭,김동현 한국회계정보학회 2023 재무와회계정보저널 Vol.23 No.3

[연구목적]본 연구는 기업의 전략적 일탈 수준에 따른 연구개발비 행태를 실증적으로 검증하였다. [연구방법]Anderson et al.(2003)에 기반한 연구모형을 설정하여, 2001년부터 2022년까지 국내 상장기업을 대상으로 실증분석을 수행하였다. [연구결과]실증분석 결과, 전략적 일탈 기업의 연구개발비에서 하방탄력적인 행태가 관찰되었다. 이는, 전략적 일탈 수준이 높은 기업일수록, 전기 대비 당기 매출 성과가 좋지 않은 상황에서 연구개발비를 과도하게 축소하려는 경향이 크다는 것을 의미한다. 즉, 전략적 일탈 기업의 경영자는 현금보유수준을 높이기 위해, 대부분 당기 비용으로 회계처리가 되는 연구개발비를 대폭 절감하려는 유인이 있다고 해석된다. 전기 대비 당기 매출액 성과가 감소하는 상황에서 전략적 일탈 수준이 높은 기업이 연구개발비를 과도하게 절감하는 행태가 있음을 보고한 본 연구결과는 기업의 전략적 일탈이 자본시장에서 불확실성 또는 위험으로 평가될 수 있다는 선행연구의 주장을 뒷받침한다. [연구의 시사점]본 연구는 국내 상장기업을 대상으로 연구개발비 행태를 전략적 일탈 수준에 따라 변동될 수 있음을 검증하였다는 데 공헌점이 있을 것이다. 특히, 기업의 전략이 연구개발비 관련 경영자의 의사결정에 유의미한 영향을 줄 수 있으며, 전략적 일탈이 기업성과의 불확실성 및 위험을 높일 수 있음을 시사한다. [Purpose]This study empirically examines the cost behavior of R&D expenditures according to the level of strategic deviance of companies. [Methodology]In this study, we set up a research model based on Anderson et al.(2003) and conduct an empirical analysis on Korean listed companies from 2001 to 2022. [Findings]As a result of empirical analysis, we find anti-stickiness cost behavior in R&D expenditures from strategic deviance companies. This means that the higher the level of strategic deviance, the greater the tendency to excessively reduce R&D expenditures if the current sales is weaker compared to the previous year. In other words, it is interpreted that managers of strategic deviance companies have an incentive to significantly reduce R&D expenditures, which are mostly accounted for at current expenses, in order to increase the level of cash holdings. [Implications]This study will contribute to verifying that the cost behavior of R&D expenditures can change depending on the level of strategic deviance for Korean listed companies. In particular, it suggests that corporate strategies can have a significant impact on the decision-making of managers related to R&D expenditures, and that strategic deviance can increase uncertainty and risk of corporate performance.

Asymptotically Optimal Solution for TSF-Constrained Staffing Problem

서승범 대한경영학회 2019 大韓經營學會誌 Vol.32 No.9

Finding the right balance between the customer service and personnel expenditure has been an important task both in practice and academia and in academia this problem was usually approached using a total cost problem. However, it is difficult to directly apply this formulation in practice and hence recent works in queueing systems have investigated this problem with staffing minimization with constraints on quality-of-service constraints. Our work contributes on this stream of works by studying TSF measure, which shows the percentage of customers who waited beyond the prespecified threshold. TSF measures the proportion of customers whose waiting time exceed a certain threshold. It is one the most prevalent kind of quality of service measure, along with ASA, which measures the average of waiting time. TSF measure is intuitive to understand and hence widely been used but has not received sufficient attention in academia. Part of the reason comes from the unnatural property of TSF measure. Once a customer waits more than the threshold, the incentive to serve that customer starkly diminishes since decreasing the eventual waiting time of him does not enhance the performance of the system. Hence a policy that is far from FIFO turns out to be more efficient. Especially we are interested in context where service level differentiation among various classes of customers. Hence, we work on V-model where multiple classes of customer and homogeneous pool of servers exist. Our task is to come up with the minimum possible number of servers while maintaining TSF measure on the pre-defined level. The decision variables are two-kind: number of servers and prioritization policy. The prioritization policy defines which class of customer to server first when a server becomes available. The nature of TSF measure, which tends to give lower priority to the customers who had already waited beyond the threshold, makes the problem more difficult to solve and hence it was usually treated in literature more added conditions or constraints added. We devise an optimal solution of TSF constrained problem without adding more structures. Since the problem is difficult to solve in exact analysis, we apply the heavy traffic technique to solve the problem. First, we show that our suggested staffing level is the lower bound for all the feasible solutions. Second, it is proved that the proposed prioritization policy combined with our staffing level actually is feasible and hence asymptotically optimal.

이차원 소재 및 응용 소자 기술 동향

서승범,장병철,최성율,Seo, Seung-Beom,Jang, Byeong-Cheol,Choe, Seong-Yul 한국정보디스플레이학회 2016 인포메이션 디스플레이 Vol.17 No.3

Minimization of Concave Holding Costs in Queueing System

서승범 연세대학교 경영연구소 2020 연세경영연구 Vol.57 No.2

Since the advent of basic  rule, minimization of holding costs has been one of the most fundamental problems in queueing theory. The first results on holding cost minimization was under the linear cost assumption and the more general case of convex costs has been solved with help of queueing approximation method named heavy traffic. Even with many sophisticated solutions on general settings, there is scarce literature that goes beyond convex or linear cost structure. Especially, a holding cost minimization problem with concave cost structure has not been discuessed yet. As far as we know, our work is the first to study concave cost structure in queueing theory. We study how the customers from multiple classes should be prioritizized. We figure out that so-called bang-bang policy is always included in the set of optimal prioritization policies when the costs are concave and that all the optimal solutions to strict concave costs are bang-bang. With this property, we construct a simple and general solution for the concoave cost minimization problem. We also provide a condition that produces a solution that assigns the whole workload to a single class.

한국 기업의 채찍효과에 대한 고찰: 코스피 상장 기업을 중심으로

서승범,박승재,Soh, Seung-Bum,Park, Seung-Jae 강원대학교 경영경제연구소 2022 Asia-Pacific Journal of Business Vol.13 No.3

Purpose - We study whether the bullwhip effect is prevalent among Korean firms and how the characteristics of it differ from the ones in other countries. Design/methodology/approach - We obtained quarterly financial and operational information on KOSPI-listed firms in manufacturing, wholesale, and retail industries from 2013 to 2019. We explore the variation of the bullwhip effect across firms and validate hypotheses. Findings - First, we find that for the KOSPI-listed firms, the bullwhip effect is more prevalent compared with the production smoothing. We provide additional findings by using sub-samples of manufacturing firms, wholesaling and retailing firms, big-sized firms, small- and medium-sized firms, domestic-sales intensive firms, and export intensive firms. Second, we show that in general, the bullwhip effect of Korean firms increases with the days in inventory or the demand seasonality ratio. However, the persistence of demand shock does not affect the bullwhip effect of Korean firms. Research implications or Originality - We compare our results with those in other studies that use information on the U.S. and Chinese firms. Our findings show that factors explaining the bullwhip effect across Korean firms have similarities and differences compared with firms in the U.S. and Chinese firms.

A Robust Lane Recognition Technique for Vision-Based Navigation with a Multiple Clue-Based Filtration Algorithm

서승범,강연식 제어·로봇·시스템학회 2011 International Journal of Control, Automation, and Vol.9 No.2

This paper proposes a novel multiple clue-based filtration algorithm (MCFA), which is developed to detect lane markings on roads using camera vision images for autonomous mobile robot navigation. The main goal of the algorithm is the robust estimation of the relative position and angle of the lane in the image by using multiple clues based on different characteristics of the lane. In particular, robustness against environmental changes is enhanced greatly since a dynamic model of the lane, be-sides static features of the lane such as color, intensity, etc., is incorporated for reliable estimation. The efficiency of the algorithm is verified through mobile robot experiments under various extreme illumi-nation conditions in outdoor environments. The increased robustness performance enables reliable closed-loop control of a mobile robot that operates in a variety of navigation-related missions.

통합물관리를 위한 유역물관리계획 체계와 수립 방안

서승범,안종호,한대호,양일주,Seo, Seung-Beom,An, Jong-Ho,Han, Dae-Ho,Yang, Il-Ju 한국수자원학회 2020 물과 미래(한국수자원학회지) Vol.53 No.5

대학생의 외모에 대한 사회문화적 태도와 몸 관리행동 간의 관계:성별 조절효과 중심으로

서승범,임수원,이혁기 한국스포츠사회학회 2014 한국스포츠사회학회지 Vol.27 No.4

This study examined body management behavior of the university students with particular focus on their sociocultural attitudes toward appearance about perceived appearance and the moderating effect of sex. Participants were 358 university students from 2 University in A metropolitan city. Data were analyzed by multiple-group analysis using Amos 18.0. The results were summarized as follows. First, sociocultural attitudes toward appearance about perceived appearance had significantly effect on body shaping. Second, sociocultural attitudes toward appearance about perceived appearance had significantly effect on body embellishment. Lastly, the moderating effect of sex were in the causal relationship between sociocultural attitudes toward appearance about perceived appearance and body shaping. But, moderating effect of sex role were in the causal relationship between sociocultural attitudes toward appearance about perceived appearance and body embellishment. 이 연구에서는 사회문화적으로 유포 되어지는 이상적인 신체기준에 대하여 대학생 개개인이 내면화하고 외모의 중요성을 지각하게 되는 사회문화적 태도와 몸 관리 행동 간의 인과관계를 구명한 후, 그 인과관계에 있어 성별에 따른 조절효과를 검정하였다. 이를 위해 A지역에 소재하는 2곳의 4년제 대학교를 재학생을 대상으로 총 358명의 대학생을 표집 하였다. AMOS 18.0 프로그램을 이용하여 다집단분석을 실시하였다. 연구결과는 다음과 같다. 첫째, 대학생의 지각된 외모에 대한 사회문화적 태도는 몸 만들기 행동에 유의한 영향을 미치는 것으로 나타났다. 이는 외모에 대한 사회문화적인 태도에 대한 대학생의 지각과 몸 만들기 행동 간에 정적인 인과관계가 있음을 의미한다. 둘째, 대학생의 지각된 외모에 대한 사회문화적 태도는 몸 가꾸기 행동에 유의한 영향을 미치는 것으로 나타났다. 이는 외모에 대한 사회문화적인 태도에 대한 대학생의 지각과 몸 가꾸기 행동 간에 정적인 인과관계가 있음을 의미한다. 셋째, 대학생의 지각된 외모에 대한 사회문화적 태도와 몸 관리 행동 간의 인과관계에 있어 성별 조절효과에 대해 각각 남성 집단과 여성 집단으로 분류하여 비교 분석하였다.

전완부 후골간 동맥 유리피판술을 이용한 안면부 조직 결손 재건 치험례

서승범,이상원,안태황,정성균,김창현,Seo, Seung Bum,Lee, Sang Won,An, Tae Whang,Jung, Sung Gyun,Kim, Chang Hyun 대한미세수술학회 2000 Archives of reconstructive microsurgery Vol.9 No.2

With esthetic concern in the reconstruction of skin and soft tissue defects of face, the use of local flap has been the method of choice. However, when there is extensive tissue loss in the face, local flaps do not provide satisfactory results. The amazing development of microsurgical technique has decreased the percentage of free flap failure, thus making free flap use in reconstruction of facial soft tissue defects. Many free flaps has been applied for reconstruction of face defects. Especially, the radial forearm flap has numerous advantages with which facial reconstruction is made possible. But, its disadvantages are ; the sacrifice of one major artery supplying the hand and donor site complications. In order to circumvent these disadvantages, we employed posterior interosseous artery(PIA) forearm free flap for the reconstruction of the face defects. The posterior interosseous forearm island flap was first described by Zancolli and Angrigiani(1985). Currently, the PIA island flap and free flap have been used for hand reconstructions. The disadvantages of the PIA flap are ; the small caliber of the pedicle, different locations of the perforating branches, and the proximity of the motor branch of the radial nerve. But, its advantages lies in preserving the major artery of the hand, minimal donor site morbidity, and fairly well matched skin texture and color, and that the flap volume is sufficient, not too bulky with convenient handling. By using this flap, we performed 1 case of tumor resection and 1 case of traumatic defect. From our experiences we conclude that it is one of many useful methods in the reconstruction of the skin and soft tissue defects of the face. We also have discussed advantages and some limitations of various free flaps for reconstruction of the face.