• Journal of Korean Society of Water and Wastewater
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• v.31 no.4
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• pp.289-296
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• 2017

Pulp and paper industry produces large volumes of wastewater and residual sludge waste, resulting in many issues in relation to wastewater treatment and sludge disposal. Contaminants in pulp and paper wastewater include effluent solids, sediments, chemical oxygen demand (COD), and biological oxygen demand (BOD), which should be treated by wastewater treatment processes such as coagulation and biological treatment. However, few works have been attempted to predict the treatment efficiency of pulp and paper wastewater. Accordingly, this study presented empirical models based on experimental data in laboratory-scale coagulation tests and compared them with statistical models such as artificial neural network (ANN). Results showed that the water quality parameters such as turbidity, suspended solids, COD, and UVA can be predicted using either linear or expoential regression models. Nevertheless, the accuracies for turbidity and UVA predictions were relatively lower than those for SS and COD. On the other hand, ANN showed higher accuracies than the emprical models for all water parameters. However, it seems that two kinds of models should be used together to provide more accurate information on the treatment efficiency of pulp and paper wastewater.

• Journal of Construction Engineering and Project Management
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• v.4 no.4
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• pp.1-8
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• 2014

The broad aim of this paper is to provide a detailed understanding of the post-war problems associated with materials for reconstruction in Libya, and to identify key problems and obstructions. Theoretical and empirical studies are being conducted in Libya. The theoretical study focuses on materials for construction and the key issues such as sources, transport and storage of materials, as well as their impact on the national economy, the nation's socio-economic development and the environment. This empirical study employed questionnaires, observations and a series of interviews with researchers, academics, suppliers and manufacturers, supported by the researcher's three decades of experience of working in the construction industry and its associated processes and operations. The empirical study illustrated that materials for post-disaster reconstruction in Libya suffer from external problems related to policies and decision-making in terms of availability of materials, fluctuation of prices of materials, specifications, building codes, legislation and regulations, and internal problems related to the construction and building material's key players: construction companies, consultancy firms, manufacturers and suppliers.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.1
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• pp.25-34
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• 2022

Established and new companies face similar business challenges in achieving performance and competitiveness. Furthermore, several empirical studies using competitive advantage resource-based view theory show that established companies achieve performance and competitiveness with breakthrough innovations. Similarly, new business ventures with limited resources must incorporate breakthrough innovations to achieve performance and competitiveness. Therefore, this study aimed to examine the impact of ambidextrous innovation on new venture performance and competitiveness. It used an online survey to collect data from 178 newly established shipping agency companies in 22 provinces in Indonesia. Data was analyzed using multivariate analysis with WarpPLS 7.0, where the analysis unit was an organization represented by a director. The results showed that ambidextrous innovation positively and significantly affects firm performance and new venture competitiveness. This means that ambidextrous innovation that emphasizes adaptation and development improves the firm's internal business processes, even with limited resources. Moreover, it increases new ventures' competitiveness in responding to threats and taking advantage of market opportunities. These results contribute to the competitive advantage resource-based view theory, specifically for new venture empirical examination. Also, they contribute to practical implications in the transportation business, demonstrating that exploitative breakthrough innovation can improve new venture competitiveness and performance.

• Journal of Korean Society on Water Environment
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• v.30 no.3
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• pp.269-282
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• 2014

The objective of this study is to find out whether the developed semi-empirical biofilm model can be applicable to real BAF pilot-scale wastewater treatment. In addition, the optimum operating conditions of BAF as a function of process variables such as organic loading change can be drawn based on the simulation results of model. The results will provide the economic and efficient BAF process design and operating control. As a result, developed semi-empirical biofilm model which is relatively simple compared to mathematical model can simulate three BAF processes consisted of 25 layers within 1 seconds. When this model was used for simulating real pilot scale BAF process and the simulated water quality values were compared to experimental ones, simulated TCOD, SCOD, TN, $NH_4{^+}$-N, $NO_x{^-}$-N, alkalinity values were different to experimental ones within 21%, 20%, 8.1%, 48%, 10%, and 23%, respectively. Therefore, if the BAF system was equipped with automatic control, the BAF process can be better efficiently adapted under the condition of significant change of influent loading.

• Atmosphere
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• v.34 no.2
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• pp.187-202
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• 2024

We analyzed the observed characteristics of monoterpene and developed an empirical formula for monoterpene concentration in the pine-dominated mixed forest of the National Center for Forest Therapy. Monoterpene was measured at 0800, 1200 and 1700 LST once a month using sorbent tube sampling coupled with thermal desorption gas chromatography and mass spectrometry. Monoterpene concentration is low in winter and shows a maximum in June and July. The major components of monoterpene are alpha-pinene, camphene and beta-pinene. During the warm period from May to November, monoterpene concentration is higher at 0800 and 1700 LST than at 1200 LST. The empirical formula takes into account the vegetation variables, temperature-controlled emission, oxidation processes and dilution by wind. The vegetation variable accounts for the difference in observed monoterpene concentration between two sites. The observed monoterpene concentration normalized by the vegetation variable increases exponentially with air temperature. The oxidation process explains the lower monoterpene concentration at 1200 LST than at 0800 and 1700 LST during the warm period. The monoterpene estimates using the empirical formula shows a correlation of 0.52 with the observation for the development period (2018~2020), while it shows a correlation of 0.72 for the validation year (2021). Such higher correlation for the validation year than for the development period is due to the fact that variability of monoterpene concentration is better explained by air temperature in 2021 than in the development period. However, the developed formula underestimates the monoterpene concentration in May and June, showing the limitation in accurately capturing the monthly variation of monoterpene.

• Journal of Technology Innovation
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• v.6 no.1
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• pp.187-214
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• 1998

This paper tries to examine the effectiveness of inventory reduction to the productivity increase and the impact of production environments on its effectiveness utilizing the Profit Impact of Market Strategy (PIMS) Database from the Strategic Planning Institute, a large data set that covers a variety of manufacturing activities from the early 1970s to late 1980s. The empirical results of this paper support the robustness of the principle of "Lean Production" or JIT system (also referred to as "Stockless Production"). We also find that the overall environment in which manufacturing strategic business units operate is an important factor in determining the different degrees of effectiveness of the work-in process (and raw materials) invertory reductions. In particular, we find that the effectiveness of the work-in process reduction varies according to the position in the product life cycly as well as the complexity and characteristics of the production processes.roduction processes.

• Journal of the Korean Operations Research and Management Science Society
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• v.35 no.1
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• pp.1-17
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• 2010

This article addresses how an organization's customer relationship management (CRM) process affects customer equity drivers and, in turn, organizational performance. By raising a three-staged model including the CRM processes, customer equity drivers, and organizational performance, the authors assert that the customer equity drivers mediate between the CRM processes and organizational performance. The empirical analysis is based on a composite survey structure that gathers data from different types of informants according to the variables. Findings indicate that the expansion process has positive relationship with all the customer equity drivers. However, the acquisition process significantly influences both perceived value equity and brand equity, and the retention process significantly influences relationship equity only. In addition, the study shows that all the customer equity drivers influence the organizational performance given the existing customers. The relationship equity among the customer equity drivers has the strongest effect on the performance.

• Journal of the Korean Operations Research and Management Science Society
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• v.18 no.3
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• pp.113-127
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• 1993

In this study, a substitution model of the evolutionary generations of technological products is presented. The purpose of the model is to examine the demand side mechanisms which generate successive product life cycles along the path of technological improvements. In the model, the nature of substitution processes is summarized dto the demand function which is derived from the consumer's udtility maximization problem. To describe the nature of technological substitution processes, the concept of the vertical differentiation and the consumption externalities are considered in the utility function. The former is used to characterize the result of technological improvement and the latter is used in explaining the inertia of demand. To show the validity of the model, an empirical study is carried out using the data of the world DRAM market.

• 한국디지털정책학회:학술대회논문집
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• 2007.06a
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• pp.181-188
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• 2007

In today's dynamic and turbulent business environment, in order to become globally competitive, many companies are trying to get closer to the customer and deliver value added product and services in the shortest possible time which demands integral ion of business processes of an enterprise. Enterprise Resource Planning (ERP) is such a strategic tool, which helps the company to gain competitive edge by integrating all business processes and optimizing the resources available. This paper throws light on how ERP evolved, what makes up an ERP system and what it has to offer to the industries. The paper includes the role of ERP, perception of ERP value, ERP plan and direction. The author also argues checkpoints as a preview to ERP introduction.

• Journal of Digital Convergence
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• v.7 no.1
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• pp.81-98
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• 2009

Understanding what lies beneath the relationship between ISP and its implementation is an significant area of inquiry in the ISP research. Through an empirical analysis and complementary case examples the current study examines this relationship at six different university sites which undergone both of these processes years from 1995 to 2001. The face-to-face, in-depth interviews were conducted to those participated in both of these processes. A questionnaire survey was also conducted to same participants to elevate the quality of the validity and reliability of the measures. Due to the limitation of the access to the data, it was not possible to compare how similar the final implementation outcomes are from what was originally planned in ISP to some sites. However the study finds that such organizational factors as management support, communication, and organizational culture at the ISP play an important role in the implementation process. This paper proposes that these organizational factors although little they seem to directly affect each individual elements in the implementation process, its latent impact is critical as a whole.