LTIS Lab. was established in 2005 and belongs to the Department of Industrial Management Engineering at Korea University.
Our Lab. provides analytical and operational support to the logistics community through the development of innovative and practical tools and techniques for the analysis and management of logistics and transportation systems.
By integrating operations research and data-driven approaches, LTIS Lab. focuses on solving practical decision-making problems in real-world logistics and transportation systems.

LTIS Lab.은 2005년에 설립되었으며 고려대학교 산업경영공학과에 소속되어 있습니다.
본 연구실은 물류 및 운송 시스템의 분석 및 관리를 위한 혁신적이고 실용적인 도구 및 기술 개발을 통해 물류 커뮤니티에 분석 및 운영 지원을 제공합니다.
LTIS Lab.은 운영 연구 및 데이터 기반 접근 방식을 통합하여 실제 물류 및 운송 시스템에서 실제 의사 결정 문제를 해결하는 데 중점을 둡니다.

Patent Data Analytics for Technology Forecasting of the Railway Main Transformer

Promising Technology Analysis and Patent Roadmap Development in the Hydrogen Supply Chain

Logistics Technology Forecasting Framework Using Patent Analysis for Technology Roadmap

CLUSTER-BASED PRIORITY LIST GENERATION FOR RESOURCE-CONSTRAINED PROJECT SCHEDULING PROBLEMS

Exploring Future Promising Technologies in Hydrogen Fuel Cell Transportation

Competing product service in an OEM supply chain with upstream module suppliers as service providers

Particle swarm optimization algorithm with time buffer insertion for robust berth scheduling

Identification of Promising Smart Farm Technologies and Development of Technology Roadmap Using Patent Map Analysis

Development of Convolutional Neural Network Architecture for Detecting Dangerous Goods for X-ray Aviation Security in Artificial Intelligence

An integrated method for berth allocation and quay crane assignment to allow for reassignment of vessels to other terminals

Identifying technology opportunities for electric motors of railway vehicles with patent analysis

The impact of technological capability on financial performance in the semiconductor industry

Identification of promising vacant technologies for the development of truck on freight train transportation systems

Identifying Technology Opportunities for Electric Motors of Railway Vehicles with Patent Analysis. Sustainability 2021, 13, 2424

Truck appointment system for cooperation between the transport companies and the terminal operator at container terminals

O-Net: Dangerous Goods Detection in Aviation Security Based on U-Net

Identification of vacant and emerging technologies in smart mobility through the GTM-based patent map development

Technological opportunity analysis: Assistive technology for blind and visually impaired people

Text mining for patent analysis to forecast emerging technologies in wireless power transfer

Firm growth and R&D in the Korean pharmaceutical industry

Pricing and collaboration in last mile delivery services

Fabless semiconductor firms’ financial performance determinant factors: Product platform efficiency and technological capability

RFID-ENABLED TRACEABILITY SYSTEM FOR PERISHABLE FOOD SUPPLY CHAINS.

Does driving range of electric vehicles influence electric vehicle adoption?

Shipment consolidation policy under uncertainty of customer order for sustainable supply chain management

Dynamic Technological Diversification and Its Impact on Firms' Performance: An Empirical Analysis of Korean IT Firms

Risk Analysis of a Two-Level Supply Chain Subject to Misplaced Inventory

Airport gate assignment for improving terminals’ internal gate efficiency

Analysis of fixed-dose combination products approved by the US food and drug administration, 2010-2015 Implications for designing a regulatory shortcut to new drug application

Optimal maintenance operations using an RFID-based monitoring system

A game theoretic approach for the optimal investment decisions of green innovation in a manufacturer-retailer supply chain

Optimal dynamic pricing and ordering decisions for perishable products

Supply chain coordination with stock-dependent demand rate and credit incentives

The dispatching rule for container logistics system with trading carbon credit adapted situation and analysis of the impact

Optimal time-based consolidation policy with price sensitive demand

Integrated pricing and capacity decision for a telecommunication   service provider

Optimal pricing and guaranteed lead time with lateness penalties

Optimal ordering policy of a risk-averse retailer subject to   inventory inaccuracy

An inventory model for perishable products with stock-dependent   demand and trade credit under inflation

Integrated inventory and transportation decision for ubiquitous   supply chain management

The impacts of an electronic marketplace with multiple independent retailers for smart grocery ordering systems

Joint inventory allocation and pricing decisions for perishable products

Ubiquitous software controller to prevent deadlocks for automated   guided vehicle systems in a container port terminal environment

The value of Electronic Marketplace in a perishable product inventory system with auto-correlated demand

Performance analysis of a multiple vehicle tandem system with   inter-vehicle buffers and blocking

The workload balancing problem at air cargo terminals

Supply Chain Network Design and Transshipment Hub Location for   Third Party Logistics Providers

Optimal dwell point location of automated guided vehicles to minimize mean response time in a loop layout

An Empirical Study on the Effect of Innovation Financing on Technology Innovation Competency: Business Performance of SMEs in Korea

Coordination contracts in a dual-channel supply chain with a risk-averse retailer

User requirement analysis and IT framework design for smart airports

Comparison of Alternative Ship-to-yard Vehicles with the   Consideration of the Batch Process of Quay Cranes

The joint replenishment and freight consolidation of a warehouse in a supply chain

Tabu search algorithm for flexible flow path design of unidirectional automated-guided vehicle systems

A multi-objective genetic algorithm for robust flight scheduling using simulation

Inventory control in the presence of an electronic marketplace

Product location, allocation and server home base location for an order picking line with multiple servers

Automated Material Handling System Design for a Wafer Fabrication Facility

Discrete Event Simulation Model for Airline Operations: SIMAIR

A Clustering Algorithm to Design the Tandem Loop Multiple Vehicle Configuration for Automated Guided Vehicle Systems

A pervasive secret sharing scheme for embedded visual communication system

Development of timed Colour Petri net simulation models for air cargo terminal operations

Optimally locating multiple dwell points in a single loop guide path system

A study of the tandem loop with multiple vehicles configuration for automated guided vehicle systems

Chulung Lee

This study aims to determine the influential factors on the market share of electric vehicles through panel data analysis based on time series data from 2011 to 2015 in 31 countries. We selected five significant independent variables that are expected to affect electric vehicle adoption based on literature review. The econometric model in this study suggests that the relative price of electric vehicle compared to internal combustion engine vehicle, driving range, and number of models available in markets are correlated to the market share of electric vehicles. On the other hand, relationship between recharging infrastructure—an important factor for electric vehicle adoption in many studies—and market share of electric vehicles turned out to be insignificant in this study. From a political point of view, we argue that policy makers need to allocate more resources to research and development in order to extend driving range at the early stage of electric vehicle deployment in the markets.

We jointly determine the price and the inventory allocation for a perishable product with a predetermined lifetime. We assume that the price of the product increases as the time when it perishes approaches as in the airline industry. Demand for the product is price sensitive. To maximize the expected revenue, we developed a discrete time dynamic programming model to obtain the optimal prices and the optimal inventory allocations for the product with a two period lifetime. We, then, proposed three heuristics when the lifetime is longer than two periods. The computational results showed that the expected revenues from the proposed heuristics were very close to that of the optimal solution. We extended these results to (i) the case where the price for the product consistently decreases; and (ii) the case where the price for the product first increases and later decreases.

Traditional methods of developing flight schedules generally do not take into consideration disruptions that may arise during actual operations. Potential irregularities in airline operations such as equipment failure are not adequately considered during the planning stage of a flight schedule. As such, flight schedules cannot be met as planned and their performance is compromised, which may eventually lead to huge losses in revenue for airlines. In this paper, we seek to improve the robustness of a flight schedule by re-timing its departure times. The problem is modeled as a multi-objective optimization problem, and a multi-objective genetic algorithm (MOGA) is developed to solve the problem. To evaluate flight schedules, SIMAIR 2.0, a simulation model which simulates airline operations under operational irregularities, has been employed. The simulation results indicate that we are able to develop schedules with …

In this paper, we determine the order quantity and the prices for a perishable product with a multiple period lifetime. Demands for products of different ages are dependent on the prices of mutually “substitutable” products. The problem for a product with lifetime of two periods is first analyzed and the stochastic dynamic programming model is developed. Given the inventory level for the old product (product of age 2), the expected profit is a concave function of the order quantity, the price of the new product (product of age 1) and the discounted price of the old product (product of age 2). The computational results show that the total profit significantly increases when demand transfers between products of different ages are considered. For a product with lifetime of longer than two periods, a heuristic based on the optimal solution for a single period problem is proposed for a multiple period problem.

In this paper, we are interested in several interrelated control issues for a ‘pick to order’ (or, ‘strict’ order picking) picking line which stores N=nk types of products in n bins, each with k shelves. To fill each order, a container is transported past the various locations containing products, and the appropriate quantity of each product is removed from its respective storage location and put into the order container using an ‘out and back’ picking strategy. Each of several pickers is assigned a set or ‘zone’ of products. We are interested in the concurrent problems of: (1) product location, (2) picker home base location, and (3) allocating products to each picker so that the expected order cycle time is minimized. We provide easily implemented algorithms to solve these problems and are able to show that the results apply for several alternate picking strategies. For fixed product locations, we develop an efficient dynamic …

We have developed joint replenishment and consolidated freight delivery policies for a third party warehouse that handles multiple items, which have deterministic demand rates in a supply chain. Two policies are proposed and mathematical models are developed to obtain the optimal parameters for the proposed policies. Four efficient algorithms are presented to solve the mathematical models for the two policies. The performances of the two policies with the parameters obtained from the proposed algorithms are then compared with the common cycle approach for 1600 randomly generated problems. The results show the robust performance of the proposed algorithm for both policies.

Governments around the world are planning to ban sales of vehicles running on petroleum-based fuels as an effort to reduce greenhouse gas emissions, and electric vehicles surfaced as a solution to decrease pollutants produced by the transportation sector. As a result, wireless power transfer technology has recently gained much attention as a convenient and practical method for charging electric vehicles. In this paper, patent analysis is conducted to identify emerging and vacant technology areas of wireless power transfer. Topics are first extracted from patents by text mining, and the topics with similar semantics are grouped together to form clusters. Then, the process of identifying emerging and vacant technology areas is improved by applying a time series analysis and innovation cycle of technology to the clustering result. Lastly, the results of clustering, time series, and innovation cycle are compared to minimize the possibility of misidentifying emerging and vacant technology areas, thus improving the accuracy of the identification process and the validity of the identified technology areas. The analysis results revealed that one emerging technology area and two vacant technology areas exist in wireless power transfer. The emerging technology area identified is circuitries consisting of transmitter coils and receiver coils for wireless power transfer, and the two vacant technology areas identified are wireless charging methods based on resonant inductive coupling and wireless power transfer condition monitoring methods or devices.

This paper investigates the robust berth allocation problem in container terminals. To handle the uncertainties in vessel arrivals, the problem is formulated as a scenario-based two-stage stochastic programming model. Furthermore, we introduce the time buffers to the model. We then develop an algorithm for time buffer insertion, which accommodates the adaptive search procedure for the time buffer into the Particle Swarm Optimization (PSO) algorithm. Different from the traditional PSO algorithm, a core operator is designed with a modified version to take the intelligent time buffer insertion approach. The results of the numerical experiments show that the proposed method consistently provides an improved performance in terms of solution quality, compared with the previous studies and the one with a traditional operator in the PSO algorithm.

In this article, we present a wearable intelligence device for activity monitoring applications. We developed and evaluated algorithms to recognize physical activities from data acquired using a 3-axis accelerometer with a single camera worn on a body. The recognition process is performed in two steps: at first the features for defining a human activity are measured by the 3-axis accelerometer sensor and the image sensor embedded in a wearable device. Then, the physical activity corresponding to the measured features is determined by applying the SVM classifier. The 3-axis accelerometer sensor computes the correlation between axes and the magnitude of the FFT for other features of an activity. Acceleration data is classified into nine activity labels. Through the image sensor, multiple optical flow vectors computed on each grid image patch are extracted as features for defining an activity. In the experiments, we …

Physical activity recognition using multiple sensors embedded in a wearable device

In this paper, we consider a supply chain which consists of a single manufacturer and a single retailer with a single product type. Demand is assumed to be dependent on the retailer's stock level. Without coordination, the retailer determines its order quantity to maximize its own profit, which is usually smaller than the manufacturer's economic production quantity. Three coordination policies are presented to coordinate the manufacturer's and the retailer's decisions. First, the credit period policy and the quantity discount policy are developed and the total profits under the two policies are compared. Then we develop a centralized supply chain policy and show that there is a unique optimal order quantity to achieve a perfect coordination. The centralized supply chain can get higher or equal channel profit while the credit period policy and the quantity discount policy are easier to achieve. Numerical examples are …

This paper presents the development and the application of simulation models for air cargo terminal operations. As air cargo volume is fast increasing in recent years, air cargo terminals which handle cargos for carriers face challenges to streamline their operations. Air cargo terminals employ diverse storage media and are also equipped with various material handling equipments. Due to the complex and stochastic nature of terminal operations, which makes formulation of analytical model difficult, in this study, simulation models are developed to analyze the air cargo terminal operations. We first employ timed CPN (Colour Petri nets) to model the terminal operations, and then the corresponding simulation model will be developed. In order to validate this simulation model, we run the model based on actual cargo retrieval schedules obtained from an air cargo terminal. The results show that this model provides a …

Recently, last mile delivery has emerged as an essential process that greatly affects the opportunity of obtaining delivery service market share due to the rapid increase in the business-to-consumer (B2C) service market. Express delivery companies are investing to expand the capacity of hub terminals to handle increasing delivery volume. As for securing massive delivery quantity by investment, companies must examine the profitability between increasing delivery quantity and price. This study proposes two strategies for a company’s decision making regarding the adjustment of market density and price by developing a pricing and collaboration model based on the delivery time of the last mile process. A last mile delivery time function of market density is first derived from genetic algorithm (GA)-based simulation results of traveling salesman problem regarding the market density. The pricing model develops a procedure to determine the optimal price, maximizing the profit based on last mile delivery time function. In addition, a collaboration model, where a multi-objective integer programming problem is developed, is proposed to sustain long-term survival for small and medium-sized companies. In this paper, sensitivity analysis demonstrates the effect of delivery environment on the optimal price and profit. Also, a numerical example presents four different scenarios of the collaboration model to determine the applicability and efficiency of the model. These two proposed models present managerial insights for express delivery companies.

The rapid advancement of digital technologies has fundamentally changed the competitive dynamics of the logistics industry. For players in the logistics industry, digitization has become an unavoidable situation to achieve survival and sustainable competitiveness. A technology strategy is essential for digitization, and identifying opportunities and threats of technology development through technology trend exploration is important for technology strategy. In addition, to enable the implementation of the technology strategy, it is necessary to detect the change in technology and search for the technology that is expected to have a practical development effect. The purpose of this study is to identify opportunities and areas for technology development through patent data in establishing technology strategies. Previous research mainly relied on the expert interview method, and there was also a patent analysis study based on topic modeling, but only to grasp technology trends. This paper aims to propose a new framework for the extension to the stage for establishing a technology roadmap. By using the Word2Vec algorithm, we will investigate the patent search formula that reflects the trend, the prediction of changes in logistics technology through LDA (Latent Dirichlet Allocation) clustering of patent data, and the derivation of vacant technology by experimental methods. The proposed framework is expected to be utilized for predicting technological change and deriving promising technologies for establishing technology roadmaps in logistics companies.

Logistics technology forecasting framework using patent analysis for technology roadmap

SIMAIR is a C++ based research tool meant for the simulation of airline operations. It provides a means for devising and evaluating various airline recovery mechanisms to handle disruptions, and can also be used as a tool to evaluate the performance of a given schedule of operations. The performance of a given recovery mechanism is quantified for research and evaluation purposes.

Discrete event simulation model for airline operations: SIMAIR

The purpose of this research was to derive promising technologies for the transport of hydrogen fuel cells, thereby supporting the development of research and development policy and presenting directions for investment. We also provide researchers with information about technology that will lead the technology field in the future. Hydrogen energy, as the core of carbon neutral and green energy, is a major issue in changing the future industrial structure and national competitive advantage. In this study, we derived promising technology at the core of future hydrogen fuel cell transportation using the published US patent and paper databases (DB). We first performed text mining and data preprocessing and then discovered promising technologies through generative topographic mapping analysis. We analyzed both the patent DB and treatise DB in parallel and compared the results. As a result, two promising technologies were derived from the patent DB analysis, and five were derived from the paper DB analysis.

Exploring future promising technologies in hydrogen fuel cell transportation

We explore the impact of research and development (R&D) on sales growth rate with firm-specific factors under the Korean pharmaceutical industry structure using listed Korea pharmaceutical company data from 2007 to 2018 with the quantile regression technique. We find that R&D intensity has a positive effect on firm growth rate while R&D scale a negative effect on the firm growth rate at the upper quantile, whereas the result is opposite at the lower quantile. Firm size has a mixed relationship with sales growth at the upper quantile, thus Gibrat’s law is rejected in the Korean pharmaceutical industry. Firm age has a negative relationship with the sales growth rate at the upper quantile, which shows the consistent result with previous research that young firms grow faster. Patent persistence has a negative relationship with sales growth at the upper quantile, while a positive effect at the lower quantile. We show that young firms and firms with high R&D intensity contribute to the high growth rate, while the relationship is not clear at the lower quantile. Therefore, policy implication in this research is that the government should pay attention to encouraging and supporting R&D investment activities and small firms as well as consider ways to enhance patent rights.

With globalization increasing countries’ trade volumes, resource management at container terminals has become more complex. To realistically address this problem, this paper proposes a methodology to solve the berth allocation and quay crane assignment problem (BACAP) while allowing the reassignment of vessels to other terminals in a multiuser container terminal. A filtered beam search (FBS)-based heuristic, a greedy randomized adaptive search procedure (GRASP)-based heuristic, and an iterative approach are integrated to provide a solution within a reasonable time frame. Numerical experiments are conducted with realistic instances from a container terminal located in Busan, Republic of Korea. The results show that the proposed approach yields a near-optimal solution with a significantly shorter computational time, compared with a commercial solver.

As life expectancy increases, the number of people who suffer from blind and visual impairment due to presbyopia is gradually increasing. Assistive device systems have been used to overcome various physical, social, infrastructure, and accessibility barriers. As technology has advanced, the scope of assistive technologies has been expanded. Therefore, we explored technological opportunities in assistive technology for the blind and visually impaired to establish a strategy for the technology competition in the near future. Firstly, the patent vacuum is detected by generating the patent map based on generative topographic mapping (GTM). Secondly, social network analysis is applied to identify the relationship between patent vacuums and occupied grid points in the patent map. Finally, the technology activity index and technology impact index are considered at quantitative and qualitative levels. Consequently, it was identified that wearable devices, including the road situation signal acquisition module and data acquisition process control module, could be occupied in the future. This study can provide practical ideas for research and development (R&D) in the field of assistive devices for the blind and visually impaired. In addition, this study can be an ample source for decision/policy makers to project new contents.

Conventional guide path layouts for automated guided vehicle (AGV) systems are analyzed, and the tandem loop with multiple vehicles (TLMV) configuration is proposed as a new and effective alternative. The TLMV configuration is especially useful for a large-scale manufacturing environment because it can easily accommodate expansion or upgrade while still being less sensitive to vehicle failure than the tandem loop (single vehicle) configuration. Simulation results show that the TLMV configuration is a viable option. The management of idle vehicles is an important control issue that affects the performance of an AGV system. For the TLMV layout, polynomial time algorithms to determine optimal idle vehicle dwell points are developed for minimizing the maximum response time and minimizing the mean weighted response time.

This paper aims to analyze the influence of the technological diversification on a firm’s innovation capabilities and investigates the effect of various strategies on the firm’s financial performance in a technology-oriented environment. We employ the entropy measurement to calculate technological diversification with 2095 patents, which are applied from years 2009 to 2011 by 507 firms that have participated in Korean government Information Technology (IT) Research and Development (R&D) supporting programs. In our framework, a firm should not diversify among the related technology fields, but should concentrate on a specific technology to reinforce the competitive advantage. However, in the case of the firms with sufficient resources, increasing technological diversification among the unrelated technology fields plays a key role on the firms’ performance. Furthermore, the degree of the technological diversification should be adjusted dynamically in compliance with the change of a firm’s innovation capabilities. Therefore, these results suggest that a firm should develop differentiated competitiveness through specialization by prioritizing its capabilities, and then exploit unrelated technological diversification to search for new opportunities.

Logistics/Transportation Information System Lab

교수님 소개

이철룽

연구실 소개

연구실 키워드

알럼나이가 간 회사

연구실 지원 방법

대우 조건

연도별 논문 인용수

저널 & 학회 논문 출판 수

연구실 논문 목록

Patent Data Analytics for Technology Forecasting of the Railway Main Transformer

Promising Technology Analysis and Patent Roadmap Development in the Hydrogen Supply Chain

Logistics Technology Forecasting Framework Using Patent Analysis for Technology Roadmap

연구실 보유 특허

대학별 입시끈

우리 연구실 모집

교수님 소개

이철룽

연구실 키워드

알럼나이가 간 회사

연구실 지원 방법

대우 조건

연도별 논문 인용수

저널 & 학회 논문 출판 수

연구실 논문 목록

Patent Data Analytics for Technology Forecasting of the Railway Main Transformer

Promising Technology Analysis and Patent Roadmap Development in the Hydrogen Supply Chain

Logistics Technology Forecasting Framework Using Patent Analysis for Technology Roadmap

연구실 보유 특허

최근 3년간 연구실적 높은 연구실

대학별 입시끈

우리 연구실 모집