• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.131-138
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• 2018

In this study, we investigated the trend of technological development in major countries related to the propulsion equipment of railway vehicles. The propulsion system is the main equipment of electric vehicles. A lot of time and investment are required in order to ensure the development of technology. Therefore, developed countries have maximized their effort to develop technologies with safety, reliability, and convenience of maintenance. They have also done their utmost to prevent technology transfer to other countries after the development of new technologies. For example, Toshiba of Japan developed a new 3,300V/1,500 A class IGBT power device, but was reluctant to export it to foreign countries in order to protect this technology. In this study, we analyzed the patents applied for related to propulsion control systems and presented the direction of development during the technical development of these systems. The patent analysis of the core technologies was conducted using the Thomson Innovation DB. We examined the number of patents applied for by country, year and major applicant. As a result of the analysis, it was found that the proportion of patent applications per country was in the order of China, 48%, Europe 16.6%, and the United States 14.9%. The patent situation of the top 10 principal applicants revealed that (the top three were?) ABB 14%, GE 13%, and CRRC 12%. At the same time, we also conducted a qualitative analysis of the level of technical development by evaluating such factors as the influence index, quotation, market securing power and citation. Based on the result of the patent analysis, we presented the direction of technical development of the propulsion control equipment of railway vehicles. Based on the analysis results, it was found that domestic applicants considerably reduced their efforts to protect their patents from foreign companies. Nowadays, most of the electric motors used in Korea are induction motors. In advanced countries, permanent magnet electric motors are employed in new railway lines. Therefore, intensive investment is needed in new developments.

• Journal of the Korean earth science society
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• v.22 no.6
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• pp.469-479
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• 2001

This study investigated the trends in the number of applicants and mean score and applicants’ responses on the test items of Earth Science in the College Scholastic Ability Test (CSAT) implemented for 3 years (1999-2001). The percentage of applicants of science track were 43.14% in 1995, but reduced through 29.5% in 2001 to 26.92% in 2002 CSAT For elective subject, about 22% of science track students applied to Earth Science II which ranked third to Biology II and Chemistry II. In 1999, test items were developed to have the expected difficulty 40 ${\sim}$ 59% (6 items) to 60 ${\sim}$ 79% (10 items). But in 2001 every 16 items were developed to have difficulty 60 ${\sim}$ 79%, which was caused by the policy of so called ‘easy CSAT’. Thus the mean score of ‘Earth Science II’ was increased from 50.26 in 1999 through 64.47 in 2000, to 67.58 in 2001. Applicants were generally very good at solving test items focusing on process skills only and familar items but poor at solving test items related to the motion of the earth and planets and sea wave, especially items calling two or more concepts. Thus special measures to cope with the decrease in applicants of science track should be provided. And it is recommended to develop test items with wider range of difficulty and to reduce test items calling process skills only. And special consideration should be given to teaching the content area with poor achievement and high actual difficulty compared to the expected.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.317-323
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• 2017

In this study, the heating performance and the energy saving effect of the heat pump system using hot waste water(waste heat) of the thermal power plant discharged from a thermal power plant to the sea were analyzed. The greenhouse area was $5,280m^2$ and scale of the heat pump system was 120 RT(Refrigeration Ton), which was divided into 30 RT, 40 RT and 50 RT. The heat pump system consisted of the roll type heat exchangers, hot waste water transfer pipes, heat pumps(30, 40, 50 RT), a heat storage tank and fan coil units. The roll type heat exchangers was made of PE(Poly Ethylene) pipes in consideration of low cost and durability against corrosion, because hot waste water(sea water) is highly corrosive. And the heating period was 5 months from October to February. During the heating performance test(12 hours), the inlet water temperature of evaporator was changed from $32^{\circ}C$ to $26^{\circ}C$, and heat absorption of he evaporator was changed from 175 kW to 120 kW. The inlet water temperature of the condenser rose linearly from $15^{\circ}C$ to $50^{\circ}C$, and the heat release of condenser was reduced by 40 kW from 200 kW to 160 kW. And the power consumption of the heat pump system increased from 30 kW to 42 kW. When the inlet water temperature of condenser was $15^{\circ}C$, the heating COP(Coefficient Of Performance) was over 7.0. When it was $30^{\circ}C$, it dropped to 5.0, and when it was above $40^{\circ}C$, it decreased to less than 4.0. It was analyzed that the reduction of heating energy cost was 87% when compared to the duty free diesel that the carbon dioxide emission reduction effect was 62% by recycling the waste heat of the thermal power plant as a heat source of the heat pump system.

• Journal of Global Scholars of Marketing Science
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• v.2
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• pp.17-37
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• 1998

중소기업간 협력 활동은 사업의 전체 혹은 일정 부분에 대하여 분업이나 협업의 관계를 맺는 공동사업의 형태로 나타난다. 기업간 연결의 강도에 따라 기업들간에 형성되는 분업과 협업의 관계를 시장형, 중간조직형, 위계조직형으로 구분할 때, 중소기업간 공동사업은 중간조직형에 속하는 일종의 기업간 네트워크라고 볼 수 있다. 물론 네트워크형의 협력관계를 추진하는 방식도 업무제휴, 지분제휴, 합작투자, 컨소시엄 등으로 다양하다. 그러나 완전한 자본적 통합에 따른 위계적 조직과는 달리 참여기업들이 독립성을 유지하면서, 네트워크 밖의 기업에 대해 경쟁우위를 확보하기 위해 형성한다는 공통점을 가지고 있다. 기업간 협력관계를 통해 참여 기업들이 얻을 수 있는 혜택에 관한 기존연구들은 크게 두 가지로 나누어 볼 수 있다. 하나는 기업의 생산함수를 중심으로 그 이점을 파악하는 것이고 다른 하나는 관계의 종류에 따라 기업간 거래관계를 관리하는 소위 거래비용의 효율성을 중심으로 혜택을 파악하는 접근방법이다. 전자의 접근방법을 따를 때, 기업간 협력의 근본 유인은 규모의 경제(혹은 비경제), 범위의 경제, 집적의 경제, 구도의 경제 등이 협력관계에서 발생하는 혜택의 근본 원천이다. 기술과 제도의 발전, 시장과 경쟁환경의 변화에 따른 기업간 협력의 필요성은 갈수록 증대되고 있다. 소비자들의 요구는 매우 개성화 다양화되고 종합화되는 추세이다. 더불어 기술개발의 비용이 큰 폭으로 증가하고 있으며, 경쟁의 격화로 기술 및 제품의 진부화도 급속도로 이루어지고 있다. 세계화 상품고도화 서비스산업화 정보화 등으로 특징지워지는 새로운 경쟁환경 아래에서 장기적으로 기업의 경쟁력을 향상시키기 위해서는 시장중심적인 관점에서 형성된 기업간 전략적 연계를 바탕으로, 정보의 집적을 통해 다양한 생산성 향상 혹은 관계효율성 향상의 경제를 추구하는 것이 필연적 전제 조건이 되었다. 기업간 경쟁보다는 최종제품의 생산과 판매를 위해 형성된 기업네트워크간의 경쟁이 중시되는 시대인 것이다. 동서간(東西間) 중소기업(中小企業)의 협력(協力)을 새삼스럽게 논의하는 것은 다분히 정치적이라는 느낌을 준다. 경제적인 관점에서 실익이 있음에도 불구하고 동서간 중소기업의 협력이 이루어지지 못하고 있다면, 그 이유는 기업정보의 수집과 유통상의 문제이거나 문화나 기업관행에 대한 잘못된 선입관에서 비롯된 관계 관리비용 계산상의 문제일 것이다. 현실적으로 이 가능성은 매우 낮다. 산업의 발전 정도나 연관성에 있어서 동서축보다는 남북축을 따라 기업간 협력이 이루어질 수 밖에 없는 우리나라의 현재 상황이 동서간보다는 남북간 경제교류를 유도하고 있는 것이다. 동서간 중서기업 협력체제의 구축에 대한 논의가 본질적으로 정치적 관심에서 비롯되었다는 전제 하에, 구축의 방안을 논의하고자 한다. 경제적으로도 타당하면서 정치적으로 관심을 유발할 수 있는 협력체제 구축방안으로, 기업간 네트워크의 조직 주체로서 최근에 논의되고 있는 새로운 형태의 마케팅회사를 동서간에 공동으로 설립할 것을 제안한다. 영구 지속적 공동사업관계보다는 프로젝트별 공동사업을 전제로 기업들 사이의 효과적인 네트워크를 형성함으로써 일종의 가상적 기업을 결성할 필요가 있다. 이러한 기업간 네트워크 형성의 실행주체가 될 수 있는 새로운 마케팅 전문기업의 형태로는 공동회사(空洞會社)(hollow company), 종합상사(綜合商社)(General Trading Company), 거래형 마케팅회사(Marketing Exchange Company), 변환형 마케팅회사(Marketing Coalition Company) 등을 들 수 있다. 양 지역에서는 소비자환경과 기술환경의 특성 및 양 지역의 경제에 대한 파급효과를 고려하여 가장 적합한 마케팅회사의 유형은 선택하여 육성하고, 이를 중심으로 강력한 양 지역 및 다른 지역에 입지한 기업간의 네트워크를 구축하여야 한다. 마케팅회사를 설립하고 완전한 마케팅 서비스를 제공할 수 있도록 육성하기 위해서는 많은 투자가 필요하다. 마케팅회사의 핵심기능 분야인 금융부문, 정보부문, 영업조직 등은 모두 막대한 투자를 필요로하는 기능영역이다. 정보부문은 기술의 발전과 범세계적인 정보관련기관과의 제휴를 통해 독자적인 구축이 어느 정도 가능하나, 영업조직의 구축을 위해서는 기존업체와의 연대가 필수적인 것으로 판단된다. 지속적으로 효과적인 기업간 네트워크를 형성하고 유지하기 위해서는 또한 기업간 관계를 관리하는 방식과 제도 및 수단에 대한 연구가 필요하다. 양 지역 산 학 관의 공동노력을 통해서 새로운 경제 환경에 가장 적합한 기업 형태로 제시된 바 있는 마케팅 전문회사 중심의 기업간 네트워크를 성공적으로 구축한다면, 양 지역 및 국가 경제의 지속적인 동력원이 될 수 있을 것이다

• Management & Information Systems Review
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• v.39 no.1
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• pp.93-114
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• 2020

Platform is considered as an alternative strategy to the traditional linear pipeline based business. Moreover, in the 4th industrial revolution period, efficiency driven pipeline business model needs to be changed to platform business. We have such success stories about platform as Apple, Google, Amazon, Uber, and so on. However, for those smaller corporations, it is not easy to find out the transformation strategy. The essence of platform business is to leverage network effect in management. Thus platform based management can be rephrased as network management across the business functions. Research on platform business is popular and related to diverse facets. But few scholars cover what the research trend of the domain is. The main purpose of this paper is to identify the research trend on platform business in Korea. To do that we first propose the analytical model for platform architecture whose components are consumers, suppliers, artifacts, and IT platform system. We conjecture that mapping of the research work on platform to the components of the model will make us understand the hidden domain of platform research. We propose three hypotheses regarding the characteristics of research and one proposition for the transitional path from pipeline to platform business model. The mapping is based on the research articles filtered from the Korea Citation Index, using keyword search. Research papers are searched through the keywords provided by authors using the word of "platform". The filtered articles are summarized in terms of the attributes such as major component of platform considered, platform type, main purpose of the research, and research method. Using the filtered data, we test the hypotheses in exploratory ways. The contribution of our research is as follows: First, based on the findings, scholars can find the areas of research on the domain: areas where research has been matured and territory where future research is actively sought. Second, the proposition provided can give business practitioners the guideline for changing their strategy from pipeline to platform oriented. This research needs to be considered as exploratory not inferential since subjective judgments are involved in data collection, classification, and interpretation of research articles.

• Economic and Environmental Geology
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• v.44 no.6
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• pp.463-474
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• 2011

The Haenam epithermal mineralized zone is located in the southwestern part of South Korea, and hosts low sulfidation epithermal Au-Ag deposit (Eunsan-Moisan) and clay quarries (Okmaesan, Seongsan, and Chunsan). Epithermal deposits and accompanying hydrothermal alteration related to Cretaceous volcanism caused large zoned assemblages of hydrothermal alteration minerals. Advanced argillic-altered rocks with mineral assemblages of alunite-quartz, alunite-dickite-quartz, and dickite-kaolinite-quartz exposed on the Okmaesan, Seongsan, and Chunsan area. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), with three visible and near infrared bands, six shortwave infrared bands, and five thermal infrared bands, was used to identify advanced argillic-altered rocks within the Haenam epithermal mineralized zone. The distinct spectral features of hydrothermal minerals allow discrimination of advanced argillic-altered rocks from non-altered rocks within the study area. Because alunite, dickite, and kaolinite, consisting of advanced argillic-altered rocks within the study area are characterized by Al-O-H-bearing minerals, these acid hydrothermal minerals have a strong absorption feature at $2.20{\mu}m$. The band combination and band ratio transformation cause increasing differences of DN values between advanced argillic-altered rock and non-altered rock. The alunite and dickite-kaolinite of advanced argillic-altered rocks from the Okmaesan, Seongsan, and Chunsan have average DN values of 1.523 and 1.737, respectively. These values are much higher than those (1.211 and 1.308, respectively) of non-altered area. ASTER images can remotely provide the distribution of hydrothermal minerals on the surface. In this way good relation between ASTER spectra analysis and field data suggests that ASTER spectral analysis can be useful tool in the initial steps of mineral exploration.

• Journal of the Korean GEO-environmental Society
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• v.24 no.12
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• pp.61-67
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• 2023

Heat pipes located underground in urban areas and operated under high temperature and pressure conditions can cause large-scale human and economic damage if damaged. In order to predict damage in advance, damage and construction information of heat pipe are analyzed to derive independent variables that have a correlation with frequency of damage, and a simple regression analysis modified model using each variable is applied to the field. However, as the correlation between independent variables applied to the model increases, the independence between variables is harmed and the reliability of the model decreases. In this study, the independence of the pipe diameter, burial depth, insulation level of monitoring system, and disconnection or short circuit of the detection line, which are judged to be interrelated, was tested to derive a method for combining variables and setting categories necessary to apply to the frequency of damage estimation model. For the test of independence, the continuous variables pipe diameter and burial depth were each converted into three categories, insulation level of monitoring system was converted into two categories, and the categorical variable disconnection or short circuit of the detection line status was kept as two categories. As a result of the test of independence, p-value between pipe diameter and burial depth, level of monitoring system and disconnection or short circuit of the detection line was lower than the significance level (α = 0.05), indicating a large correlation between them. Therefore, the pipe diameter and burial depth were combined into one variable, and the categories of the combined variable were set to 9 considering the previously set categories. The insulation level of monitoring system and the disconnection or short circuit of the detection line were also combined into one variable. Since the insulation level is unreliable when the detection line status is disconnection or short circuit, the categories of the combined variable were set to 3.

• Journal of Life Science
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• v.12 no.6
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• pp.700-707
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• 2002

To study the characteristics of organic and nutrient removal by Bacillus species at high COD concentration of influent, three lab-scale batch reactors(R1, R2, R3), each of which has different substrate composition, were operated. More than 95% of $NH_4^+$-N and $COD_{cr}$, concentrations were removed under an aerobic condition, and their removal efficiencies were found to be 22.6 and 90.5%(R1), 23.9 and 65.8%(R2), 30.2 and 86.4%(R3), respectively. The removal efficiency of $NH_4^+$-N was high when an enough amount of $NO_3^{-}$-N was supplied, and that of $COD_{cr}$. was low when a high concentration of initial $NO_2^{-}$-N was added. The amount of carbon utilized in denitrification was a little. In all reactors,$NO_3^{-}$-N was removed under an anoxic condition, but in the R3 reactor, 10% of $NO_3^{-}$-N could be removed even undo, an aerobic condition. The removal efficiencies of TN and TP were 41.8 and 49.5%(R1), 40.1 and 35.8%(R2), 47.0 and 57.6%(R3), respectively. Alkalinities destructed under an aerobic condition for each reactor were 4.96, 5.41 and 3.93 mg/L (as $CaCO_3$) per each gram of $NH_4^+$-N oxidized, respectively, while 3.06, 3.17 and 2.60 mg/L (as $CaCO_3$) of alkalinities were produced for each gram of ,$NO_3^{-}$-N reduced to $N_2$. The SOUR were found to be 38.5, 52.7 and 42.0 mg $O_2$/g MLSS/hr, which indicated that Bacillus sp. had a higher cell activity than activated sludge. The OLR and sludge production were estimated to be 0.69 and 0.28(Rl), 0.77 and 0.20(R2), 0.61 kg COD/$m^3$/day and 0.25 kg MLSS/kg COD(R3), respectively. From the N-balance, the highest percentage(40.9%) of nitrogen lost to $N_2$ was obtained in the R3 reactor. From all the results, the possibility of aerobic denitrification Bacillus sp. has been shown and the B3 process seemed to have two advantages: a little amount of carbon was required in denitrification and not much amount of alkalinity was destructed under an aerobic condition.

• Journal of Intelligence and Information Systems
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• v.26 no.3
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• pp.149-169
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• 2020

"The Urban Renewal New Deal project", one of the government's major national projects, is about developing underdeveloped areas by investing 50 trillion won in 100 locations on the first year and 500 over the next four years. This project is drawing keen attention from the media and local governments. However, the project model which fails to reflect the original characteristics of the area as it divides project area into five categories: "Our Neighborhood Restoration, Housing Maintenance Support Type, General Neighborhood Type, Central Urban Type, and Economic Base Type," According to keywords for successful urban regeneration in Korea, "resident participation," "regional specialization," "ministerial cooperation" and "public-private cooperation", when local governments propose urban regeneration projects to the government, they can see that it is most important to accurately understand the characteristics of the city and push ahead with the projects in a way that suits the characteristics of the city with the help of local residents and private companies. In addition, considering the gentrification problem, which is one of the side effects of urban regeneration projects, it is important to select and implement urban regeneration types suitable for the characteristics of the area. In order to supplement the limitations of the 'Urban Regeneration New Deal Project' methodology, this study aims to propose a system that recommends urban regeneration types suitable for urban regeneration sites by utilizing various machine learning algorithms, referring to the urban regeneration types of the '2025 Seoul Metropolitan Government Urban Regeneration Strategy Plan' promoted based on regional characteristics. There are four types of urban regeneration in Seoul: "Low-use Low-Level Development, Abandonment, Deteriorated Housing, and Specialization of Historical and Cultural Resources" (Shon and Park, 2017). In order to identify regional characteristics, approximately 100,000 text data were collected for 22 regions where the project was carried out for a total of four types of urban regeneration. Using the collected data, we drew key keywords for each region according to the type of urban regeneration and conducted topic modeling to explore whether there were differences between types. As a result, it was confirmed that a number of topics related to real estate and economy appeared in old residential areas, and in the case of declining and underdeveloped areas, topics reflecting the characteristics of areas where industrial activities were active in the past appeared. In the case of the historical and cultural resource area, since it is an area that contains traces of the past, many keywords related to the government appeared. Therefore, it was possible to confirm political topics and cultural topics resulting from various events. Finally, in the case of low-use and under-developed areas, many topics on real estate and accessibility are emerging, so accessibility is good. It mainly had the characteristics of a region where development is planned or is likely to be developed. Furthermore, a model was implemented that proposes urban regeneration types tailored to regional characteristics for regions other than Seoul. Machine learning technology was used to implement the model, and training data and test data were randomly extracted at an 8:2 ratio and used. In order to compare the performance between various models, the input variables are set in two ways: Count Vector and TF-IDF Vector, and as Classifier, there are 5 types of SVM (Support Vector Machine), Decision Tree, Random Forest, Logistic Regression, and Gradient Boosting. By applying it, performance comparison for a total of 10 models was conducted. The model with the highest performance was the Gradient Boosting method using TF-IDF Vector input data, and the accuracy was 97%. Therefore, the recommendation system proposed in this study is expected to recommend urban regeneration types based on the regional characteristics of new business sites in the process of carrying out urban regeneration projects."

• The Korean Journal of Petroleum Geology
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• v.8 no.1_2 s.9
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• pp.1-43
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• 2000

A comparison study for understanding a stratigraphic response to tectonic evolution of sedimentary basins in the Yellow Sea and adjacent areas was carried out by using an integrated stratigraphic technology. As an interim result, we propose a stratigraphic framework that allows temporal and spatial correlation of the sedimentary successions in the basins. This stratigraphic framework will use as a new stratigraphic paradigm for hydrocarbon exploration in the Yellow Sea and adjacent areas. Integrated stratigraphic analysis in conjunction with sequence-keyed biostratigraphy allows us to define nine stratigraphic units in the basins: Cambro-Ordovician, Carboniferous-Triassic, early to middle Jurassic, late Jurassic-early Cretaceous, late Cretaceous, Paleocene-Eocene, Oligocene, early Miocene, and middle Miocene-Pliocene. They are tectono-stratigraphic units that provide time-sliced information on basin-forming tectonics, sedimentation, and basin-modifying tectonics of sedimentary basins in the Yellow Sea and adjacent area. In the Paleozoic, the South Yellow Sea basin was initiated as a marginal sag basin in the northern margin of the South China Block. Siliciclastic and carbonate sediments were deposited in the basin, showing cyclic fashions due to relative sea-level fluctuations. During the Devonian, however, the basin was once uplifted and deformed due to the Caledonian Orogeny, which resulted in an unconformity between the Cambro-Ordovician and the Carboniferous-Triassic units. The second orogenic event, Indosinian Orogeny, occurred in the late Permian-late Triassic, when the North China block began to collide with the South China block. Collision of the North and South China blocks produced the Qinling-Dabie-Sulu-Imjin foldbelts and led to the uplift and deformation of the Paleozoic strata. Subsequent rapid subsidence of the foreland parallel to the foldbelts formed the Bohai and the West Korean Bay basins where infilled with the early to middle Jurassic molasse sediments. Also Piggyback basins locally developed along the thrust. The later intensive Yanshanian (first) Orogeny modified these foreland and Piggyback basins in the late Jurassic. The South Yellow Sea basin, however, was likely to be a continental interior sag basin during the early to middle Jurassic. The early to middle Jurassic unit in the South Yellow Sea basin is characterized by fluvial to lacustrine sandstone and shale with a thick basal quartz conglomerate that contains well-sorted and well-rounded gravels. Meanwhile, the Tan-Lu fault system underwent a sinistrai strike-slip wrench movement in the late Triassic and continued into the Jurassic and Cretaceous until the early Tertiary. In the late Jurassic, development of second- or third-order wrench faults along the Tan-Lu fault system probably initiated a series of small-scale strike-slip extensional basins. Continued sinistral movement of the Tan-Lu fault until the late Eocene caused a megashear in the South Yellow Sea basin, forming a large-scale pull-apart basin. However, the Bohai basin was uplifted and severely modified during this period. h pronounced Yanshanian Orogeny (second and third) was marked by the unconformity between the early Cretaceous and late Eocene in the Bohai basin. In the late Eocene, the Indian Plate began to collide with the Eurasian Plate, forming a megasuture zone. This orogenic event, namely the Himalayan Orogeny, was probably responsible for the change of motion of the Tan-Lu fault system from left-lateral to right-lateral. The right-lateral strike-slip movement of the Tan-Lu fault caused the tectonic inversion of the South Yellow Sea basin and the pull-apart opening of the Bohai basin. Thus, the Oligocene was the main period of sedimentation in the Bohai basin as well as severe tectonic modification of the South Yellow Sea basin. After the Oligocene, the Yellow Sea and Bohai basins have maintained thermal subsidence up to the present with short periods of marine transgressions extending into the land part of the present basins.