텍스트마이닝 기법을 활용한 게임 스트리밍 애플리케이션 리뷰 분석 : 디지털 경쟁력 강화를 위한 연구

JIN WENHUI,이정우 한국디지털정책학회 2022 디지털융복합연구 Vol.20 No.4

BERT를 이용한 딥러닝 기반 소스코드 취약점 탐지 방법 연구

김문회(Wenhui Jin),오희국(Heekuck Oh) 한국정보보호학회 2022 정보보호학회논문지 Vol.32 No.6

효율적 데이터 의존성 분석을 이용한 바이너리 기반 Null Pointer Dereference 취약점 탐지 도구

김문회(Wenhui Jin),오희국(Heekuck Oh) 한국정보보호학회 2023 정보보호학회논문지 Vol.33 No.2

널 포인터 역참조 (Null Pointer Dereference) 취약점은 정상적인 메모리 주소를 저장한 포인터가 아닌 널 포인터를 참조할 때 발생하는 취약점이다. 그러므로, 서비스거부공격 (Denial-of-service)와 같은 공격에 악용되어 큰 피해를 줄 수 있기 때문에 식별하고 제거해야 할 중요한 취약점이다. 기존 연구에서는 기호실행과 같은 정적분석을 통해 취약점을 탐지하는 방법을 많이 제안하였다. 그러나 커널과 같은 복잡도가 높은 대형 프로그램을 검사할 때는 경로폭발 (path explosion)과 제약조건(constraint solver) 때문에 효율성이 제한되며 주어진 시간 내에 탐지하지 못할 수 있다. 또는 대형 프로그램 중 일부 함수들 혹은 라이브러리 함수를 탐지할 때 전체 프로그램의 상태를 알 수 없기 때문에 완전한 분석을 수행하지 못해 정확도가 높지 않은 경우가 있다. 본 논문에서는 소스코드가 없는 대규모 프로그램에서 특정한 일부 기능 검사 할 때 빠르고 정확하게 검사하기 위한 가벼운 취약점 탐지도구를 연구개발 하였다. 변수나 포인터를 기호로 표시하고 프로그램 실행을 에뮬레이션하여, 각 실행경로에서 데이터 의존성(data dependency) 분석과 휴리스틱 방법으로 널 포인터 역참조 취약점을 탐지한다. 기존 bap_toolkit과 실험하여 비교하였을 때 오탐율이 8% 높지만, 존재하는 취약점을 모두 탐지해냈다. The Null Pointer Dereference vulnerability is a significant vulnerability that can cause severe attacks such as denial-of-service. Previous research has proposed methods for detecting vulnerabilities, but large and complex programs pose a challenge to their efficiency. In this paper, we present a lightweight tool for detecting specific functions in large binary programs through symbolizing variables and emulating program execution. The tool detects vulnerabilities through data dependency analysis and heuristics in each execution path. While our tool had an 8% higher false positive rate than the bap_toolkit, it detected all existing vulnerabilities in our dataset.

교차성을 활용한 상호문화교육 연구-드라마 <SKY 캐슬>을 중심으로-

JIN MEISHAN,장인하,WANG WENHUI,정은선 국제한국어교육학회 2023 한국어 교육 Vol.34 No.1

Korean dramas (i.e., K-dramas) reveal cultural complexities, thus making themselves useful educational material. Taking the K-drama “SKY Castle” as an example, this study applies an intersectional lens to analyze educational issues within the Korean context and diverse cases of intercultural communication among international students in Korea. By applying intersectionality, it explores the possibilities of cultural education from the perspective of interculturalism to help international students better understand other cultures. The analysis results indicate educational content. Then, based on these suggested contents, we collect the responses of actual learners to research and explore the possibilities of educational application through case studies. Our findings show that the introduction of intersectionality into intercultural education allows learners to view and understand other cultures and individuals from various perspectives as well as recognize the structure of the society surrounding such individuals to create a three-dimensional space and opportunity for critical communication.

Overexpression of IbMPK3 increases low-temperature tolerance in transgenic sweetpotato

Jin Rong,Kim Ho Soo,Yu Tao,Liu Ming,Yu Wenhui,Zhao Peng,Zhang Aijun,Zhang Qiangqiang,Liu Yaju,Cao Qinghe,Kwak Sang-Soo,Tang Zhonghou 한국식물생명공학회 2022 Plant biotechnology reports Vol.16 No.1

Sweetpotato is an important crop that is very sensitive to low temperatures. Mitogen-activated protein kinase (MAPK) is involved in plant growth and development and is responsive to many environmental stresses. IbMPK3 is strongly regulated by low-temperature stress. We studied the function of IbMPK3 and how it may enhance the adaptability of sweetpotato plants to low-temperature stress. Transgenic sweetpotato plants overexpressing IbMPK3 were generated, and three trans- genic lines with the highest expression level of IbMPK3 were used for low-temperature tests. Transgenic plants exposed to low-temperature stress had less damage associated with higher photosynthesis efficiency and less cell membrane damage. IbMPK3-overexpressing transgenic plants could modulate reactive oxygen species (ROS) metabolism with lower levels of O2− and H2O2 accumulation and higher enzymatic activities than WT plants. Transcript expression levels of some ROS- related genes (IbCAT, IbCu-ZnSOD, and IbCAT) and stress-responsive genes (IbP3B and IbCOR27) were significantly upregulated in transgenic plants compared to WT. These results indicate that IbMPK3 has an important role in sweetpotato response to low temperatures.

Wetting Behavior of Liquids on Micro-Patterned Polymer Surfaces Fabricated by Thermal Imprinting

Kwang-jin Bae,Wenhui Yao,Yiliang He,Young-rae Cho 대한금속재료학회(구 대한금속학회) 2017 대한금속·재료학회지 Vol.55 No.9

Abstract: The wetting behavior of liquids on solid surfaces is important in the study of surfaces and interfaces. In this study, the wetting behavior of deionized (DI) water and hexadecane on fluorinated and micro-patterned polymer surfaces was investigated. The sample surfaces were processed by spray coating and thermal imprinting, respectively. The apparent contact angle and sliding angle of each sample were measured. Hexadecane, which has a low surface tension, spread easily over the micro-patterned surface, indicating oleophilicity. However, the apparent contact angle of DI water on the micro-patterned surface was approximately 134.2°, indicating that the surface was hydrophobic. Although the apparent contact angle of DI water on the micro-patterned surface indicated hydrophobicity, the sliding angle was very high at 60º. These results indicated that DI water droplets on the micro-patterned surfaces have an intermediate wetting state between the Wenzel and Cassie-Baxter states. Based on the experimental results, it was concluded that the wetting behavior of DI water droplets on the micro-patterned surfaces is determined by the force balance between the capillary force and the air counterforce. (Received April 3, 2017; Accepted May 14, 2017)

Transparent, conductive, and superhydrophobic nanocomposite coatings on polymer substrate

Yao, Wenhui,Bae, Kwang-Jin,Jung, Myung Yung,Cho, Young-Rae Academic Press 2017 Journal of Colloid and Interface Science Vol. No.

<P><B>Abstract</B></P> <P>Transparent, conductive, and superhydrophobic nanocomposite coatings were fabricated on the polyethylene terephthalate substrate by a spray method. Different concentrations of multi-walled carbon nanotubes (MWCNTs) entwined with SiO<SUB>2</SUB> nanoparticles, which originated from the hydrolysis and condensation of tetraethyl orthosilicate, were sprayed to form MWCNTs/SiO<SUB>2</SUB> nanocomposite coatings. The coatings were characterized by scanning electron microscopy, contact angle measurements, and other analytical techniques. The surface morphology, hydrophobicity, transparency, and conductivity of the nanocomposite coating were found to be strongly dependent on the MWCNT concentration. With increasing MWCNT concentration, the hydrophobicity increased first and then decreased, and the optical transmittance and sheet resistance decreased. The enhanced hydrophobicity was associated with the surface microstructure and chemical composition of the coating. The decreased hydrophobicity resulted mainly from the decrease in the trapped air between the water droplet and the nanocomposite coating. Owing to the hierarchically porous 3-dimensional microstructure and opportune fluorinated MWCNT content, the nanocomposite coating with 0.2wt% MWCNTs exhibited the best hydrophobicity with a contact angle of 156.7°, good transparency with 95.7% transmittance and relatively high conductivity with a sheet resistance of 3.2×10<SUP>4</SUP> Ωsq<SUP>−1</SUP>.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Statistical tolerance–cost–service life optimization of blade bearing of controllable pitch propeller considering the marine environment conditions through meta-heuristic algorithm

Zeng Wenhui,Yi Jin,Lin Rongfu,Lu Wenlong 한국CDE학회 2022 Journal of computational design and engineering Vol.9 No.2

Blade bearing is the key mechanism of the controllable pitch propellers (CPPs) to adjust the pitch to change the thrust. In the marine environment, wear and deformation of the contact surface of the blade bearing are quite large, which may result in leakage to reduce the service life of CPP. However, most studies on tolerance optimization of blade bearing disregard deformations and wear, and it could result in unreasonable tolerances and impair the CPP’s service life. In this paper, to establish the statistical tolerance–cost–service life optimization model of the blade bearing of the CPP considering the marine environment effects in propellers, a prediction model about the relationship between the thrust and rotation speed of the CPP considering environment conditions of wind, wave, and ocean currents is constructed. Based on this, the wear and deformation are simulated according to the predicted rotation speed in the marine environment. Considering the deformation and wear in the marine environment, a tolerance analysis model of the assembly deviations of the blade bearing is introduced, and the assembly characteristics and functional requirements are established and converted into probability constraints to establish the service-life model based on statistical tolerance analysis and Monte Carlo simulation methods. Afterward, a statistical tolerance–cost–service life optimization model is established and transformed into a single-objective optimization problem through the normalization method and the weighted sum method, and solved by a meta-heuristic algorithm named cuckoo search. Finally, the application of the proposed model is demonstrated through a case involving the blade bearing of a CPP, and the optimized results show that the manufacturing cost of the blade bearing is reduced and its service life is extended.

Investigation of flow-regime characteristics in a sloshing pool with mixed-size solid particles

Cheng, Songbai,Jin, Wenhui,Qin, Yitong,Zeng, Xiangchu,Wen, Junlang Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.5

To ascertain the characteristics of pool sloshing behavior that might be encountered during a core disruptive accident of sodium-cooled fast reactors, in our earlier work several series of experiments were conducted under various scenarios including the condition with mono-sized solid particles. It is found that under the particle-bed condition, three typical flow regimes (namely the bubble-impulsion dominant regime, the transitional regime and the bed-inertia dominant regime) could be identified and a flow-regime model (base model) has been even successfully established to estimate the regime transition. In this study, aimed to further understand this behavior at more realistic particle-bed conditions, a series of simulated experiments is newly carried out using mixed-size particles. Through analyses, it is verified that for present scenario, by applying the area mean diameter, our previously-developed base model can provide the most appropriate predictive results among the various effective diameters. To predict the regime transition with a form of extension scheme, a correction factor which is based on the volume-mean diameter and the degree of convergence in particle-size distribution is suggested and validated. The conducted analyses in this work also indicate that under certain conditions, the potential separation between different particle components might exist during the sloshing process.

20(S)-Ginsenoside Rh2 displays efficacy against T-cell acute lymphoblastic leukemia through the PI3K/Akt/mTOR signal pathway

Ting Xia,Jin Zhang,Chuanxin Zhou,Yu Li,Wenhui Duan,Bo Zhang,Min Wang,Jianpei Fang 고려인삼학회 2020 Journal of Ginseng Research Vol.44 No.5

Background: T-cell acute lymphoblastic leukemia (T-ALL) is a kind of aggressive hematological cancer, and the PI3K/Akt/mTOR signaling pathway is activated in most patients with T-ALL and responsible for poor prognosis. 20(S)-Ginsenoside Rh2 (20(S)-GRh2) is a major active compound extracted from ginseng, which exhibits anti-cancer effects. However, the underlying anticancer mechanisms of 20(S)-GRh2 targeting the PI3K/Akt/mTOR pathway in T-ALL have not been explored. Methods: Cell growth and cell cycle were determined to investigate the effect of 20(S)-GRh2 on ALL cells. PI3K/Akt/mTOR pathway-related proteins were detected in 20(S)-GRh2-treated Jurkat cells by immunoblotting. Antitumor effect of 20(S)-GRh2 against T-ALL was investigated in xenograft mice. The mechanisms of 20(S)-GRh2 against T-ALL were examined by cell proliferation, apoptosis, and autophagy. Results: In the present study, the results showed that 20(S)-GRh2 decreased cell growth and arrested cell cycle at the G1 phase in ALL cells. 20(S)-GRh2 induced apoptosis through enhancing reactive oxygen species generation and upregulating apoptosis-related proteins. 20(S)-GRh2 significantly elevated the levels of pEGFP-LC3 and autophagy-related proteins in Jurkat cells. Furthermore, the PI3K/Akt/mTOR signaling pathway was effectively blocked by 20(S)-GRh2. 20(S)-GRh2 suppressed cell proliferation and promoted apoptosis and autophagy by suppressing the PI3K/Akt/mTOR pathway in Jurkat cells. Finally, 20(S)-GRh2 alleviated symptoms of leukemia and reduced the number of white blood cells and CD3 staining in the spleen of xenograft mice, indicating antitumor effects against T-ALL in vivo. Conclusion: These findings indicate that 20(S)-GRh2 exhibits beneficial effects against T-ALL through the PI3K/Akt/mTOR pathway and could be a natural product of novel target for T-ALL therapy.