AUTOMATIC DATA PROCESSING SYSTEM FOR INTEGRATED COST AND SCHEDULE CONTROL OF EXCAVATION WORKS IN NATM TUNNELS

Cho, Daegu,Cho, Hunhee,Kim, Daewon Vilnius Gediminas Technical University 2014 Journal of Civil Engineering and Management Vol.20 No.1

<P>A type-based system is widely used for cost and schedule control in the NATM (New Austrian Tunnelling Method) tunnel. This study raises several limitations of the type-based system: a broad level of control, a distributed approach to cost and schedule data, ad hoc management, and difficulty in deriving meaningful data. Integrated cost and schedule control promises a myriad of benefits on both information flow and construction management. Nevertheless, the integrated approach still seems to be a long way from common use in the construction industry because it requires considerable overhead effort to acquire, track, and analyze the integrated data. The objective of this study is to propose a new method to automate the required processes for implementing cost and schedule integration. We propose an operational-level automatic data processing system for cost and schedule integration. The proposed system consists of a real-time location system for detecting equipment locations, a wireless mesh network for transmitting the location signals to a field office, and a prototype model for transforming the signals to cost and schedule data. Technical feasibility is analyzed through a pilot project. The study offers a new approach to facilitating sensor technologies for cost and schedule integration.</P>

중국 민영기업가의 리더십 유형에 대한 사례연구

조대원 ( Cho Daewon ) 한국비교경제학회 2021 비교경제연구 Vol.28 No.1

중국의 개혁개방 40년사에서 민영기업의 성공과 성장은 중요한 업적으로 우선적으로 강조되고 있으며 이러한 중국 민영기업의 성장은 기업가들의 리더십과 직접적인 인과관계에 있다고 해도 과언이 아니다. 본 논문에서는 중국의 주요 민영기업가를 1980년대, 1990년대, 2000년 전후의 3세대로 나누어 그 특징을 살펴보았고, 이들 기업가들의 리더십 유형을 추진자형, 지배자형, 분석자형, 보조자형의 4가지로 분류하여 기업가별로 그들의 리더십이 경영활동과 의사결정에 어떻게 발현되었는지에 대해 구체적인 사례를 살펴보았다. In the 40-year history of China’s reform and opening up, the success and growth of private enterprises has been emphasized as an important achievement, and it is no exaggeration to say that the growth of such Chinese private enterprises has a direct causal relationship with the leadership of entrepreneurs. In this thesis, major private entrepreneurs in China were divided into three generations before and after the 1980s, 1990s, and 2000s, and the characteristics of these entrepreneurs were divided into four types: propulsion type, ruler type, analyst type, and assistant type. By categorizing them, specific examples of how their leadership was expressed in management activities and decision-making were examined.

The immediate effects of local vibration on ankle plantar flexor muscle activation and peak torque in healthy adults

Cho, Minjo,Yoon, Doyoo,Yoo, Jaehyun,Yi, Donghyun,Kang, Daewon,Yim, Jongeun korean Academy of Physical Therapy Rehabilitation 2020 Physical therapy rehabilitation science Vol.9 No.2

Objective: The vibration device is one of the most commonly used warm-up devices not only for healthy athletes but also for healthy individuals. Therefore, this study aimed to investigate the immediate effects of local vibration on ankle plantar flexor muscle activation and peak torque in healthy adults. Design: One-group pretest-posttest design. Methods: This was a single-group study comprising a total of 36 (16 males and 20 females) participants. The average age of the 36 participants was 22.3 years. All the participants' concentric and eccentric peak torques of the gastrocnemius lateralis muscle were measured using an isokinetic device. Simultaneously, the participants' muscle activity was measured by surface electromyography. After the pre-experimental data were collected, the participants comfortably sat on the prepared chair with their hips and knees flexed to 90°. While in sitting position, local vibration was applied for 10 minutes using a 1:1 ratio intermittent pulsing mode device based on a previous study. Then, the post-experimental data were collected immediately after the local vibration by performing a similar process performed during the pre-experimental data collection. Results: The results showed a significant difference in muscle activity and eccentric peak torque (p<0.05). On the contrary, concentric peak torque values showed an insignificant difference with pre- and post-value. Conclusions: The results of this study demonstrated that local vibration can be possibly considered as one of the effective ways to increase ankle plantar flexor muscle activity and muscle performance, specifically the eccentric peak torque, in healthy adults.

Bioalcohol production from acidogenic products via a two-step process: A case study of butyric acid to butanol

Cho, Seong-Heon,Kim, Juyeon,Han, Jeehoon,Lee, Daewon,Kim, Hyung Ju,Kim, Yong Tae,Cheng, Xun,Xu, Ye,Lee, Jechan,Kwon, Eilhann E. Elsevier 2019 APPLIED ENERGY Vol.252 No.-

<P><B>Abstract</B></P> <P>This article presents the full study (lab-scale experimental study and large-scale techno-economic analysis) results of a two-step catalytic process for the conversion of organic waste–derived butyric acid to butanol. The two-step process consists of the (1) esterification of butyric acid to methyl butyrate and (2) hydrogenolysis of this methyl butyrate to butanol. The first reaction, esterification of butyric acid, was optimized using carbon-based catalysts. The production of butanol from methyl butyrate via hydrogenolysis was investigated using bimetallic Pt–Co catalysts. The hydrogenolysis of methyl butyrate on these catalysts under optimal conditions of 250 °C, 5 MPa H<SUB>2</SUB>, and a feed/catalyst weight ratio of 11.2 led to 54.1% selectivity toward 1-butanol. Based on the experimental results, an integrated process simulation model was developed to determine the economic potential of the two-step production of butanol from butyric acid. Using this model, the techno-economic feasibility of the two-step process was analyzed. The minimum selling price (MSP) of 1-butanol produced from butyric acid using this process was US$ 3.388 per gallon of gasoline equivalent (GGE). This MSP is in the range of recent biofuel market prices of US$ 2.03/GGE to US$ 3.83/GGE.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A full study of butanol production using experiments and simulations was conducted. </LI> <LI> A two-step process to produce butanol from butyric acid is suggested. </LI> <LI> Butanol can be produced with a 0.231 g/g yield via the two-step process. </LI> <LI> Minimum selling price of butanol is US$ 3.388 per gallon of gasoline equivalent. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Cervical Radiculopathy Caused by Spinal Epidural Arteriovenous Fistula (SEDAVF) Without Intradural Drainage: A Case Report and Literature Review

Daewon Park,Donghan Kim,Dong-Hun Kang,Subum Lee,Dae-Chul Cho 대한신경손상학회 2022 Korean Journal of Neurotrauma Vol.18 No.1

Spinal epidural arteriovenous fistula (SEDAVF) is a rare vascular malformation. Due to the mass effect of enlarged epidural veins and venous hypertension, progressive radiculopathy and myelopathy are likely to occur. A 33-year-old female presented with right upper extremity weakness for a month. The cause of this symptom was a SEDAVF, which was located near the C5-6-7 foramens and compressed the nerve roots. In the absence of intradural venous drainage, endovascular treatment is often difficult because of the large venous pouch. We performed endovascular trapping of the vertebral artery (VA) and loose packing of the coil material on the AVF to minimize mass effects. Immediately after embolization, the fistula was occluded, but a small new feeder vessel developed a day later. An n-butyl cyanoacrylate embolization was performed, and the fistula was successfully occluded.

Quench Detection Method of HTS Model Coil Using a Series-Type Thermocouple

Daewon Kim,Jin-Geun Kim,A-Rong Kim,Minwon Park,In-Keun Yu,Ki-Deok Sim,Seockho Kim,Jeonwook Cho,Myung-Hwan Sohn IEEE 2011 IEEE transactions on applied superconductivity Vol.21 No.3

<P>This paper proposes a quench detection method applied to a HTS coil and also discusses the results of tests on an HTS BSCCO wire and an HTS YBCO coil. A series-type thermocouple was fabricated to detect quench, where several thermocouples were welded in series. As the series-type thermocouple has many points of detection, variation in temperature was detected at each point by using thermo-electromotive force. The feasibility of the proposed method was investigated through the quench detection tests on the YBCO coil. This method has advantages such as a simple structure and cost effectiveness and also protects the HTS coil by detecting partial quench and its propagation.</P>

Interference of L1 Phonological Processes in English Learning

Daewon Park,Shinsook Lee,Mi-Hui Cho 한국영어학학회 2010 영어학연구 Vol.16 No.3

The present study examined the impact of L1 phonological processes on English learning by conducting a production experiment on 20 Korean high school students with different levels of English proficiency. In particular, the students’ production of English n-l sequenced words (e.g., only, fan letter, boneless, lonely) and m-l sequenced words (e.g., homeland, home loan, harmless, calmly) was investigated in order to find out the influence of Korean /n/-lateralization (e.g., /non-li/ [nol.li]‘logic’, /nan-lo/ [nal.lo]‘stove’) and /l/-nasalization (e.g., /kam-li/ [kam.ni] ‘supervision’, /kΙm-li/ [kΙm.ni]‘interest rate’) on the acquisition of the English sound system. Another point of consideration in the present study was the effect of morphological information such as word and suffix types on the production of English words (e.g., single words vs. compound words vs. derived words). The overall results showed that the impact of L1 phonological processes was evident, but that the degree of impact varied with the nature of phonological processes. More specifically, the students had more production difficulty with the n-l sequenced words than with the m-l sequenced words irrespective of their English proficiency, which shows that the effect of Korean lateralization is more persistent than that of Korean nasalization. Yet, the high proficiency-level students overall outperformed the low proficiency-level students. Moreover, the results indicated that the students’performance was affected by target words’morphological information such as word and suffix types, as the students’production of compound words was better than that of single words, which was in turn better than that of derived words across English n-l sequenced and m-l sequenced words. Theoretical and pedagogical implications for L2 sound acquisition were drawn, along with directions for future research.

인공신경망을 이용한 타이어 FLAT SPOT 성능 예측 프로그램 개발

최대원(Daewon Choi),김형태(Hyoungtae Kim),김기현(Gihyun Kim),조명국(Myeongguk Cho) 한국자동차공학회 2010 한국자동차공학회 학술대회 및 전시회 Vol.2010 No.11

Tire Flat Spot is due to a vehicle parked without moving for a in general, tire flat spot phenomenon will be disappeared when a driver have a tire rolled for a few minutes. Flat spot is a low harmonic phenomenon and primarily contributes to the third or fourth harmonics of tire run out. The tire non uniformity caused by a flat spot may induce noticeable vibrations in some vehicles during operation in the decay process. The magnitude and decay of a flat spot depends on many factors ? tire construction, material creep properties, tire radial load and time duration, inflation, tire and ambient temperatures, tire mileage, etc. This paper represents a prediction system that can Prediction the tire Flat-Spot in advance before making tire. The neural network algorithm of data-mining was applied for this Prediction program. This program will indicate tire design guide line to tire engineer correctively and quickly.

퍼지 추론 및 인공 신경망 알고리즘 결합에 의한 타이어 회전저항 예측

최대원(Daewon Choi),김기현(Gihyun Kim),장석희(Sukhee Jang),박태구(Taeku Park),조춘택(Choontack Cho) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

Tire manufacturers are trying to reduce the tire rolling resistance for decreasing vehicle fuel consumption. Tire rolling resistance is caused by hysteretic losses of various tire components. This paper represents a prediction system that can forecast the tire rolling resistance in advance before making tire. The algorithm of Fuzzy Inference and Neural Network was applied tor this prediction system. Tire construction and component factors were treated by Fuzzy Inference and Neural Network Algorithm respectively. The achievement of this paper will be applied to automotive and tire industry to reduce energy consumption.

데이터마이닝을 적용한 타이어 회전저항 성능 예측 프로그램 개발

최대원(Daewon Choi),김기현(Gihyun Kim),조춘택(Choontack Cho) 한국자동차공학회 2009 한국자동차공학회 학술대회 및 전시회 Vol.2009 No.11

Tire manufacturers are trying to reduce the tire rolling resistance for decreasing vehicle fuel consumption. Tire rolling resistance is caused by hysteretic losses of various tire components. This paper represents a prediction system that can forecast the tire rolling resistance in advance before making tire. The neural network algorithm of data-mining was applied for this estimation program. This program will indicate tire design guide line to tire engineer correctively and quickly. The achievement of this paper will be applied to automotive and tire industry to reduce energy consumption.