Earticle

This paper reviews an implementation strategy of activity breakdown for the assessment of process time. In addition, the study proposes the classification models for estimating the process time of Time-Driven Activity-Based Costing (TDABC) based on various types of activity breakdown structures, including activity interface perspective, activity decomposition perspective and activity priority perspective.

하폐수처리공정은 복잡한 생물학적 처리과정과 많은 입력변수들의 시간에 따른 강력한 동적인 변동성으로 인해서 이 전의 운전 상황이 차후의 운전상황에 많은 영향을 미친다. 이런한 현상을 시간지연 효과라 한다. 강력한 비선형 매핑 (mapping) 특성 때문에 신경망은 구조 기반 모델에 대한 모델링 및 식별 도구로서의 이점을 제공하지만, 일반 인공신경 망(ANN)의 경우 시스템 설계방식(architecture)의 결정 및 시스템에서의 시간 지연과 관련된 주요 입력 변수의 선택은 쉽 지 않다. 그래서 본 연구에서는 시간 지연 신경망과 유전자 알고리즘을 결합한 유전자 적응형 시간 지연 신경망 (GATDNN)을 개발하여 바덴포(Bardenpho) 고도하수처리 공정 모델링에 적용하였다. GATDNN에서 3 단계 모델링 절차 가 수행되었다. (1) 각 특정 출력에 대한 예측 정확도를 극대화하기 위해 중요한 입력 변수 선택 (2) ANN 기반 프로세스 추정기에 적합한 네트워크 토폴로지(topology)를 찾기 (3) 민감도 분석. 모델링 결과 GATDNN을 사용하여 제시된 모델 링 기술이 높은 정확도로 출력을 예측하고 주요 작동 변수를 식별하는 데 유용한 도구임을 보여주었다. 이 작업은 고도 하수처리장 운전을 위한 신뢰할 수 있는 제어 전략의 개발을 가능하게 하여 엔지니어의 부담을 줄여 줄 수 있다.

Wastewater treatment systems are characterized by large temporal variability of inflow, variable concentrations of components in the incoming wastewater to the plant, and highly variable biological reactions within the process. The behavior of observed process variables within a wastewater treatment plant (WWTP) at a certain time instant is the combined effect of various processes initiated at different moments in the past. This is called a time-delay effect in the system. Due to the nature of strong nonlinear mapping, neural networks provide advantages as a modeling and identification tool over a structure-based model. However, the determination of the architecture of the artificial neural networks (ANNs) and the selection of key input variables with a time delay is not easy. In our research, a genetic adapted time-delay neural network (GATDNN), which is a combination of time-delay neural network (TDNN) and genetic algorithms (GAs), was developed and applied to the full-scale Bardenpho advanced sewage treatment process. In a GATDNN, a three-step modelling procedure was performed: (1) selection of significant input variables to maximise the predictive accuracy for each specific output; (2) finding a suitable network topology for the ANN-based process estimator; (3) sensitivity analysis. The results demonstrate that the modelling technique presented using a GATDNN provides a valuable tool for predicting the outputs with high levels of accuracy and identifying key operating variables. This work will permit the development of a reliable control strategy thus reducing the burden of the process engineer.

Conventional case-based reasoning (CBR) does not perform efficiently for high-volume datasets because of case retrieval time. To overcome this problem, previous research suggested clustering a case base into several small groups and retrieving neighbors within a corresponding group to a target case. However, this approach generally produces less accurate predictive performance than the conventional CBR. This paper proposes a new case-based reasoning method called the clustering–merging CBR (CM-CBR). The CM-CBR method dynamically indexes a search pool to retrieve neighbors considering the distance between a target case and the centroid of a corresponding cluster. This method is applied to three real-life medical datasets. Results show that the proposed CM-CBR method produces similar or better predictive performance than the conventional CBR and clustering-CBR methods in numerous cases with significantly less computational cost.

Since Aït-Sahalia (2002)’s seminal work on obtaining a closed-form approximate transition probabil- ity density function (ATPDF) of a univariate time-homogeneous di¤usion process, many researchers employed his idea to extend it to more general cases. Those include ATPDFs of univariate time- inhomogeneous di¤usions (Egorov, Li, and Xu (2003)), likelihood expansions of multivariate time- homogeneous di¤usions (Aït-Sahalia (2008)), ATPDFs of multivariate time-homogeneous jump di¤u- sions (Yu (2007)), likelihood expansions of multivariate time-inhomogeneous di¤usions (Choi (2013)), and ATPDFs of multivariate di¤usions (Choi (2015)). This article considers getting an explicit form of an ATPDF for multivariate time-inhomogeneous jump di¤usion processes which encompass all of the aforementioned models. Using the Kolmogorov partial di¤erential equation (PDE), we …rst …nd PDEs of the coe¢ cients of the ATPDF. These PDEs can be solved and we can get the formulas to retrieve all coe¢ cients of the ATPDF successively when the multivariate time-inhomogeneous jump di¤usion is reducible. However, if it is not reducible we can no longer solve the PDEs. In this case, Taylor-expanding the coe¢ cients and matching the same orders in the PDEs yield an ATPDF for the time-homogeneous jump di¤usion. But in the case of time-inhomogeneous jump di¤usion, the similar indeterminacy problem to Choi (2013) occurs. We prove that all of the generally nonzero indeterminate terms are cancelled out in the TPDF expansion. The ATPDF can be utilized to a variety of areas including maximum likelihood estimation, asset pricing, and Bayesian analysis.

This paper provides a new theoretical approach to investigate the sensitivity of the familiar beta of the capital asset pricing model (CAPM) to the length of the return measurement interval; a phenomenon known as the Intervalling effect. By setting the problem in a continuous time setting, and using exact results, we are able to generalize existing results in the literature. We derive an expression for beta as a function of the time horizon h, conditional on current time t. We show that beta is monotonic in h and derive conditions for it to be increasing or decreasing.

본 연구는 우리나라에서 상대적으로 적용사례가 적은 비시장-가치평가기법인 개인별 여행비용접근법(Individual Travel Cost Method, TCM)를 사용하여, 국책사업으로 추진 중인 새만금 간척사업지와 인접해 있는 변산반도 국립공원의 방문수요함수를 추정하고 이를 바탕으로 관련 자연환경자원의 사용가치를 측정하고자 한다. 전통적인 TCM모형을 확장하여, 화폐소득과 시간소득의 두 예산제약 조건 하에서 효용극대화과정을 전개함으로써 자연환경자원의 방문수요함수를 완전가격(full price)과 완전소득(full income)의 함수로 도출하였다. 나아가서 방문수요함수의 종속변수인 방문빈도가 비음의 정수(non-negative integers)인 점을 감안하여 방문빈도를 연속함수로 보는 전통적인 회귀분석에서 포아송(Poisson)이나 음이항(Negative Binomial) 모형 등의 카운트자료(count data) 모형으로 확장하였다. 또한 비방문자들을 수요함수 추정에서 제외함으로써 발생할 수 있는 표본선택편의(sample selection bias)를 완화하기 위하여 방문여부함수와 방문빈도함수를 결합추정하였다. 전국에서 무작위로 추출된 1,303명의 일반가구 소비자들로 구성된 표본을 사용하여 실증분석을 수행한 결과, 종속변수를 연속변수로 취급하느냐 아니면 카운트 자료모형으로 취급하느냐에 따라 가격변수의 계수추정치에 차이가 있었고, 이는 소비자들의 관련 지점에 대한 사용가치를 반영하는 접근가치의 측정에도 반영이 되었다. 그리고 여가시간의 기회비용을 가격과 소득에 포함시키느냐의 여부 역시 계수추정치와 편익추정치에 영향을 미쳤다. 그러나 방문여부에 따른 표본선택편의의 가능성은 존재하기는 하였지만, 방문수요함수의 계수추정치나 편익추정치에 미치는 영향은 비교적 적은 편이었다.

This paper extends the standard individual travel cost method (TCM) by incorporating values of leisure time in both price and income variables, and the data generating process (treatment of trip frequency and sample selection effects) into recreation demand models for a national park. Recognizing the important role of leisure time in recreation demand, full prices and full incomes were derived from two-constraint (money and time budgets) models, in which the marginal value of leisure time was assumed to be a fraction of market wage rates. Count data models such as Poisson or Negative Binomial models, compared with the Tobit model, were reviewed to reflect the non-negative integer nature of the dependent variable (numbers of trips taken over the year) in recreation demand models. Equally important, Probit-tobit and Probit-poisson selection models were developed to take into account effects of no visitors at a recreational site in a general household survey. Empirical results from a survey of 1,303 households randomly selected throughout the nation suggest that the inclusion of values of leisure time and treatments of dependent variables affected estimates of price and income coefficients, and therefore estimates of the value of access to the site as a welfare measure. However, the selection effects alone were less definitive both in demand parameter and welfare measure estimates.

본 연구의 목적은 근거이론방법을 통해 시간제 청소년동반자가 청소년상담 전문가로 적응해가는 과정에 대한 실체이론을 개발하는데 있다. 이를 위해 상담관련 전공 대학원 석사수료 이상의 학력으로 청소년상담사 등 상담관련 자격증을 소지하였으며, 3년 이상 시간제 청소년동반자로 활동하고 있는 15명을 대상으로 심층면접을 진행하였다. 연구결과 첫째, 개방코딩에서 116개의 개념과 40개의 하위범주, 15개의 범주가 도출되었다. 둘째, 축코딩에서는 시간제 청소년동반자의 청소년상담 적응과정 패러다임 모형을 구축하였다. 또한 범주와 하위범주들이 상호작용하며 연결되는 과정분석의 결과 시간제 청소년동반자의 청소년상담 적응과정은 시간의 흐름에 따라 입문, 혼란(만족:갈등), 이해와 수용, 적응과 지속이라는 4단계로 나타났다. 셋째, 선택코딩에서 ‘힘들고 어렵지만 청소년과 함께하는 동반자의 길을 걷기로 함’이라는 핵심범주가 도출되었고, 유형화 작업을 통해 ‘확신형’, ‘현실형’, ‘과정형’의 세 가지 유형이 도출되었다. 본 연구는 시간제 청소년동반자의 청소년상담 적응과정에서 나타나는 변화와 그에 영향을 미치는 인과적 조건, 맥락적 조건, 중재적 조건, 작용/상호작용 전략들을 파악함으로써 청소년동반자의 적응과정에 대해 포괄적으로 설명하였다.

This study aimed to develop a substantial theory on the adjustment process of part-time youth companions as youth counseling experts through the grounded theory method. For this purpose, in-depth interviews were conducted with 15 partcipants who were enrolled in counseling master's programs at least completing their coursework, who were licensed youth counselors, and who had been practicing as youth companions for more than three years. Results were as follows. First, from open coding, 116 concepts, 40 sub-categories, and 15 categories emerged. Second, axial coding constructed a paradigm model for the adjustment process of part-time youth companions to‘ youth counseling. In addition, an analysis of the process in which categories and sub-categories were connected and interacted showed that the adjustment process of part-time youth companions to’ youth counseling consisted of four stages as time went by(i.e.,, introduction, confusion (satisfaction:conflict), understanding/ acceptance, and adjustment/maintenance. Third, from selective coding, the core category, ‘hard and difficult but deciding to walk the way of a companion with adolescents’ emerged, and through the categorization process, three types, ‘confirmation-type,’ ‘reality-type,’ and ‘process-type,’ were drawn. This study comprehensively explained part-time youth companions’ adjustment process to counseling with adolsents by exploring changes in the counseling process as well as by examining conditions(i.e., causal, contextual, and interventional) and action/interaction strategies influencing those changes.

본 연구의 목적은 보호관찰 초범 청소년들이 재비행 없이 보호처분을 적응적으로 이행하는 과정과 이에 영향을 미치는 요인을 탐색하는 것이다. 이를 위하여 보호관찰 준수사항 위반 및 위법한 비행을 하지 않고 1년 이상을 경과한 평균 연령 17.7세의 초범 청소년 10명을 대상으로 면담하고 근거이론 방법(Strauss &Corbin, 1998)의 주요 절차에 따라 자료를 분석하였다. 개방코딩 절차를 통해 127개의 개념, 44개의 하위범주와 18개의 범주를 도출하였다. 축코딩 단계에서 범주들을 패러다임에 연관시키면서 범주간의 관계성을 파악하고, 초범 청소년이 보호관찰을 적응적으로 이행하는 과정을 시간의 흐름에 따라 ‘저항적 갈등’, ‘소극적 시도’, ‘적극적 실천’, ‘자율적 조절’, ‘희망 내딛기’의 5단계로 도출하였다. 핵심범주는 ‘책임을 수용하고 심리적·사회적 손상을 만회하며 조심스럽게 희망을 다져나감’으로 상정하였다. 본 연구는 보호관찰 초범 청소년들과의 면담을 통해 재비행 없이 1년 이상 처분을 이행한 경험의 구조와 과정을 통합적으로 탐색함으로써, 이들이 보호관찰을 성공적으로 마치고 일상생활로 복귀하도록 도울 개입의 실제적인 근거와 자료를 제공하였다는 의의가 있다.

The purpose of this study was to explore the adaptive probation process of the first-time juvenile offender without re-delinquency and the factors affecting it. To accomplish this purpose, 10 first-time juvenile offenders with an average age of 17.7 who had not committed any delinquency or not violated the probation rules for one year or longer were individually interviewed. The data analysis was based on Grounded theory method(Strauss & Corbin, 1998). In the Open Coding process, 127 concepts, 44 subcategories, and 18 categories were derived. In the Axial Coding, categorical and process analyses were conducted through paradigms. In the process analysis step, the adaptive fulfillment process of the first-time juvenile probationers was divided into five stages: ‘the resistant-conflict stage’, ‘the passive-attempt stage’, ‘the positive-practice stage’, ‘the autonomous-regulation stage’, and ‘the hope-advancing stage.’ The core category in the Selective Cording was ‘cautiously advancing the hope, accepting responsibilities and committing to make up for psychological and social damage’ This study is meaningful in that it explored the structure and process of the probation disposition for more than a year without committing any delinquency through interviews with the first-time juvenile offenders. It also provides the practical basis and data to support intervention to help them successfully finish the probation and return to normal life.

Workers are avoiding production/manufacturing sites due to the poor working environment and concern over safety. Small and medium-sized businesses introduce new equipment to secure safety in the production site or ensure effective process management by introducing the real-time monitoring technique for existing equipment. The importance of real-time monitoring of equipment and process in the production site can also be found in the ANSI/ISA-195 model. Note, however, that most production sites still use paper-based work slip as a process management technique. Data reliability may deteriorate because information on the present condition of the production site cannot be collected/analyzed properly due to manual data writing by the worker. This paper introduces the monitoring and process management technique based on a direct facility interface to secure safety in the field by improving the poor working environment and enhance there liability and real-time characteristics of the production data. Since the data is collected from equipment in real-time directly through the SIB-based interface and PLC-based interface, problems associated with workers’ manual data input are expected to be solved; safety can also be improved by enhancing workers’ attention to work by minimizing workers’ injuries and disruption.

SBR 처리공정의 자동제어 인자로서의 ORP, pH, DO의 안정성과 유용성을 비교 평가하였다. 시스템 운전동안 ORP와 pH(mV)-time profile 상에서 오염물질의 특이적인 변화시점을 나타내는 NBP와 NKP가 잘 나타났으며 이 시점은 MSC(moving slope change)를 이용하여 쉽게 인식될 수 있는 것으로 밝혀졌다. 그러나 부하량과 포기량 혹은 시스템 OUR이 불균형일 때는 DO나 ORP-time profile 상에서 NBP로 잘못 인식될 수 있는 가짜 제어시점이 여러 번 발생하거나 혹은 제어시점으로 인식할만한 변화가 전혀 발생하지 않음을 알 수 있었다. 그러나 pH(mV)-time profile에서는 어떤 운전조건과 상태에서도 항상 뚜렷한 NBP가 발생하고 MSC를 이용한 제어시점 인식이 가능함을 알 수 있었다. 따라서 호기적 처리과정 중의 시스템 진단과 자동제어 인자로 ORP나 DO 보다 pH(mV)가 안정적임을 알 수 있었다. 반면 무산소 상태의 모니터나 제어에 있어서는 pH(mV)-time profile에서 NKP를 안정적으로 인식하는 데에는 한계가 있었으나 ORP에서는 매우 안정적인 것으로 나타나 무산소 처리과정의 진단/제어인자로는 ORP가 다른 인자들 보다 유용함을 알 수 있었다. 이러한 결과로 미뤄 SBR 공정의 안정적인 자동제어를 위해서는 ORP 혹은 pH(mV)를 단독으로 이용하는 것 보다는 병용하는 것이 바람직하며, 이러한 자동제어기술은 유입수내 오염물질의 농도 변이와 운전여건에 상관없이 항상 오염물질의 완전제거를 가능케 함은 물론 처리시간 및 처리용량의 최적화를 위한 실용적 기술이 될 것으로 판단된다.

The feasibility and stability of ORP, pH(mV) and DO as a real-time control parameter for SBR process were evaluated in this study. During operation, NBP(nitrogen break point) and NKP(nitrate knee point), which reveal the biological and chemical changes of pollutants, were clearly observed on ORP and pH(mV)-time profiles, and those control points were easily detected by tracking the moving slope changes(MSC). However, when balance of aeration rate to loading rate, or to OUR(oxygen uptake rate), was not optimally maintained, either false NBP was occurred on ORP and DO curves before the appearance of real NBP or specific NBP feature was disappeared on ORP curve. Under that condition, however, very distinct NBP was found on pH(mV)-time profile, and stable detection of that point was feasible by tracking MSC. These results might mean that pH(mV) is superior real-time control parameter for aerobic process than ORP and DO. Meanwhile, as a real-time control parameter for anoxic process, ORP was very stable and more useful parameter than others. Based on these results, a stable real-time control of process can be achieved by using the ORP and pH(mv) parameters in combination rather than using separately. A complete removal of pollutants could be always ensured with this real-time control technology, despite the variations of wastewater and operation condition, as well as an optimization of treatment time and capacity could be feasible.

프로세스 모니터링은 프로세스를 수행하는 과정에서 발생하는 조직 내외부에서 발생하는 다양 한 사건 관련 정보를 지속적으로 관측하여 이에 대한 실시간 접근성을 제공한다. 이를 위해 프로세스 진행 중에 기록되는 데이터와 최종 수행 결과 간의 상관관계를 추출하여 룰로 정의하고 룰의 조건부 를 탐색하는 접근법이 널리 사용된다. 그러나 이러한 룰 기반 모니터링을 실시간 프로세스 진행 상황 에 적용하는 경우, 지표의 부재 및 늦은 감지의 문제가 한계점으로 등장한다. 이를 해결하기 위하여 본 논문에서는 대체 기법을 도입한 실시간 프로세스 모니터링 방법론을 제안하였다. 대체 기법이란 전 체 데이터 테이블에서 누락된 데이터를 대신할 수 있는 특정 값을 찾기 위한 기법이다. 실시간으로 진 행 중인 프로세스를 모니터링하는 상황에서 관측 시점에 따라 필연적으로 존재하는 비관측 정보를 데 이터 결측으로 간주하고 대체 기법을 이용하여 발생 가능한 추후 진행 상태를 추정할 수 있다. 제안 된 대체 기반 실시간 프로세스 모니터링을 통해 프로세스 진행 중 전 관측 시점에 걸쳐 현 진행 시점 까지 수집된 정보에 근거한 최종 수행 결과를 실시간으로 예측할 수 있다.

Process monitoring provides a real-time access to critical process attributes generated during process executions. A widely used approach for process monitoring is a rule-based monitoring. It detects specific conditions about attributes causing corresponding results, which is defined in If (condition) Then (status) rule. However, when the rule-based approach is applied to a real-time process monitoring that attributes are recorded sequentially along with execution order of tasks, it shows some limitations like no indicator or late warnings. To improve these limitations, we propose a novel approach for real-time process monitoring by adopting imputation for treating unobserved attributes. Imputation aims at replacing missing or non-sampled attributes with any specific unit with similar characteristics. During the real-time monitoring, there exist unobserved attributes according to the real-time progress of ongoing processes, which can be considered as inevitable missing with monitoring period. In this situation, imputation methods can be used to assume probable progress after the period. Therefore, probable outcomes given the current progress of ongoing process can be predicted in real-time during entire monitoring periods.

Responses of real-time control parameters, such as ORP, DO and pH, to the conditions of biological animal wastewater treatment process were examined to evaluate the stability of real-time control using each parameter. Also an optimum index for supplemental carbon source addition based on NOx-N level was determined under a consideration of denitrification rate by endogenous respiration of microorganism and residual organic matter in liquor. Experiment was performed with lab-scale sequencing batch reactor(SBR) and working volume of the process was 45L. The distinctive nitrogen break point(NBP) on ORP-and DO-time profiles, which mean the termination of nitrification, started disappearing with the maintenance of low NH4-N loading rate. Also the NBP on ORP-and DO-time profiles was no longer observed when high NOx-N was loaded into the reactor, and the sensitivity of ORP became dull with the increase of NOx-N level. However, the distinctive NBP was constantly occurred on pH(mV)-time profile, maintaining unique profile patterns. This stable occurrence of NBP on pH(mV)-time profile was lasted even at very high NOx-N:NH4-N ratio(over 80:1) in reactor, and the specific point could be easily detected by tracking moving slope change(MSC) of the curve. Revelation of NBP on pH(mV)-time profile and recognition of the realtime control point using MSC were stable at a condition of over 300mg/L NOx-N level in reactor. The occurrence of distinctive NBP was persistent on pH(mV)-time profile even at a level of 10,000mg/L STOC(soluble total organic carbon) and the recognition of NBP was feasible by tracing MSC, but that point on ORP and DO-time profiles began to disappear with the increase of STOC level in reactor. The denitrfication rate by endogenous respiration and residual organic matter was about 0.4mg/L.hr., and it was found that 0.83 would be accepted as an index for supplemental carbon source addition when 0.1 of safety factor was applied.

KRX 유가증권시장은 2019년 4월 29일 시가단일가매매 호가접수시간(“시가단일가매매시간”)을 1시간에서 30분으로 단축하였다. 이 논문은 시가단일가매매시간에서 외국 인과 기관투자자가 가격발견에 미치는 영향력을 파악하고자, 이 사건을 전후로 시가단 일가매매시간을 5분 단위로 나누어 투자자별 호가 제출 패턴과 WPC(“가중가격공헌 도”)의 횡단면 결정요인을 분석하였다. 사건 전후 50 거래일 동안 모든 호가를 분석한 결과 첫째, 외국인과 기관투자자는 개인투자자와는 달리 장 후반에 호가를 집중·제출 하는 패턴을 보인다. 또한 같은 시간대에 정정·취소호가 비중도 매우 높아 시가단일 가매매 체결시점에 가까워질수록 가격을 적극 조정하며 정보거래자로서 시가 발견에 큰 영향을 끼친다. 둘째, 시가단일가매매에서 WPC를 결정하는 요인은 장 개시 초반 (“WPC 최초 계산 구간”)과 장 후반(“WPC 조정 구간”)이 서로 반대로 나타나는 특징을 보인다. 장 개시 초반에는 외국인과 기관투자자의 참여가 낮은 종목이나 규모가 작은 종목에서 가격발견이 빠르게 이뤄지는 반면, 장 후반에는 외국인과 기관투자자의 참여 가 높거나 변동성이 낮은 종목, 또는 대기업 종목이 가격발견을 주도한다. 셋째, 시가 단일가매매 후반부는 초반 오버슈팅한 WPC에 조정 국면이 일어나 시가라는 균형가격 발견을 촉진하는데 이 시간대에서 외국인과 기관투자자의 호가제출 비중은 신규/정정 /취소호가에서 모두 WPC의 횡단면 결정에 통계적으로 강한 양(+)의 요인으로 작용한 다. 이는 외국인과 기관투자자가 정보거래자로서 전략적으로 행동하며 시가단일가매 매의 가격발견에 주도적인 영향을 끼치는 것을 뜻한다. 또한 단축 조치로 시가단일가 매매시간이 짧아졌음에도 외국인투자자의 가격발견 속도에 미치는 영향력은 더욱 커 졌다. 이상의 분석 결과들은 단축 이전과 이후 대체로 유사해 단축 이전 장 초반 30분은 노이즈가 많은 불확실성을 내포한 시간임을 알 수 있어 KRX 유가증권시장의 제도 개선 효과는 긍정적이었음을 시사한다.

On April 29, 2019, the Korea Exchange (KRX) reduced the duration of the pre-market opening call auction—referred to as the opening call auction session—from 60 minutes to 30 minutes in its KOSPI market. This study examines the impact of this policy change by analyzing how foreign and institutional investors contribute to price discovery during the shortened auction period. Specifically, we divide the opening call auction session into 5-minute intervals and investigate investor-specific order submission patterns and the cross-sectional determinants of Weighted Price Contribution (WPC), both before and after the change. Using data from all submitted orders over 50 trading days before and after the event, we find the following key results: First, order submission behavior differs markedly across investor types. Retail investors predominantly submit their orders during the early part of the auction session, whereas foreign and institutional investors tend to concentrate their order submissions toward the latter part of the session. Moreover, the proportion of revised and canceled order by foreign and institutional investors increases significantly near the end of the session, suggesting active price adjustment behavior. This implies that these investors behave as informed traders, delaying order submission to the final stages in order to avoid premature information disclosure and to exert greater influence over price determination of the latter part of the session. As a result of these strategic behaviors, foreign and institutional investors exhibit significantly higher order execution rates, reinforcing their dominant role in the price discovery process. Second, the determinants of Weighted Price Contribution (WPC)—used to measure the contribution of submitted orders to the opening price—vary across time segments within the call auction and reveal contrasting dynamics between the early and late phases. Specifically, the initial stage of the auction (the “WPC initial computation interval”) is the first opportunity for market participants to incorporate overnight information that has become available since the previous day’s close. During this phase, price discovery tends to occur more rapidly in stocks with lower participation by foreign and institutional investors, smaller firm sizes, higher volatility, or greater liquidity. In contrast, the latter part of the call auction (the “WPC adjustment interval”) is characterized by a reversal in these determinants. In this phase, price discovery is primarily driven by stocks that have higher participation from foreign and institutional investors, lower volatility, or larger firm sizes. This suggests that investor composition, and stock characteristics exert different influences on price formation depending on the stage of the auction. Interestingly, at the moment of opening price determination—the final order-matching point—price discovery again accelerates in stocks with lower foreign investor participation or smaller firm sizes, diverging from the characteristics observed during the immediately preceding phase. This reversal implies a process similar to a tatonnement mechanism (as in a Walrasian auction), wherein the market undergoes a trial-and-error adjustment process to reach an equilibrium price. Third, the adjustment of WPC in the latter stage of the auction session is primarily driven by the strategic behavior of foreign and institutional investors. Initially, WPC often reflects overshooting caused by overreactions from retail investors, who act as noise traders. As the auction progresses and approaches the final price determination point, WPC declines—sometimes turning negative— indicating a correction process toward a more accurate equilibrium price. During this adjustment phase, foreign and institutional investors shift from a passive stance in the early phase to an active role in the latter part of the session, submitting a large proportion of new, revised, and canceled orders that play a crucial role in correcting earlier mispricings. This behavior is empirically supported by the statistical analysis showing that the share of foreign and institutional orders during this phase exhibits a strong and positive correlation with cross-sectional WPC values, reinforcing their pivotal role in leading the price discovery process. The overall analysis demonstrates that these patterns hold consistently before and after the 2019 policy change, in which the KRX reduced the length of the opening call auction from 60 minutes to 30 minutes. This consistency implies that the first 30 minutes of the original one-hour session may have contained a high degree of market noise and uncertainty, resulting in inefficiencies in the price discovery process. The shortening measure of the opening call auction period did not diminish the role of foreign and institutional investors; rather, their strategic contributions to price discovery remained intact. These findings suggest that the policy change had a positive effect on market efficiency of this session. In conclusion, the differentiated behavior of investor types, the shifting determinants of WPC, and the strategic timing of informed traders’ order submissions together illustrate the complex dynamics underlying price discovery in a compressed opening call auction environment.

본 기업적용 사례는 2011년 8월 시작된 전장(자동차 전자 부품, 이하 전장) S/W 공동 개발 정부 프로젝트(대기업 자동차부품업체 총괄 주관, 중소/벤처 5개 업체 참여 공동 개발)에 CMMI L3 프로세스를 기반으로 한 일정관리 프로세스 개선 모델을 적용하고 효과를 분석한 것이다. 조직 규모가 작고 프로젝트 관리 성숙도가 낮은 중소/벤처 업체들은 CMMI L3 프로세스 준수가 어렵기 때문에 일정관리 프로세스를 테일러링 하기 위하여 정부 프로젝트에 참여하고 있는 중소/벤처 업체들의 프로젝트 관리 성숙도를 CMMI 성숙도 진단표를 사용하여 진단하고 이를 바탕으로 SW 공동 개발 일정관리 프로세스 개선 모델을 도출하고 이를 적용하여 사양 고정 단계(3개월)를 진행 하였다. 개선 모델을 적용하지 않았던 과거 유사 2개 프로젝트 사양고정 단계까지의 계획 대비 실적을 분석하여 효과를 입증한 사례를 공유 하고자 한다.

This case study is an application of improvement process model of time management process to collaborative automotive S/W R&D projects with small business from August 2011 based on the CMMI L3 process and analysis of the effect of the application. Since small-sized(immature-management system) company is hard to comply with CMMI L3 process the degree of normality of the project management of the small-sized companies that participate the project was diagnosed using CMMI checkup table to tailor the time management process, and an improvement model of the time management process of software collaborative development which is applied to make results in fixing requirements phase was derived. The purpose of this paper is to share the results to fixing requirements phase among the similar two projects that the improvement model were not applied and this project.