An Investigation on Ultimate Strength of High Strength Aluminum Alloys Four-Bolted Connections with Out-of-plane Deformation

BoKyung Hwang,TaeSoo Kim 한국강구조학회 2019 International Journal of Steel Structures Vol.19 No.4

An experimental study for the structural behaviors of high strength aluminum alloys (7075-T6) single shear bolted connections with three types of bolt arrays has been carried out by authors. Out-of-plane deformation in the direction of plate thickness (hereafter, curling) occurred in some specimens with long end distances parallel to the direction of applied force. It is known that the curling reduced ultimate strength for curled specimens and it contributed to deciding the ultimate state of 7075-T6 bolted connections. In this paper, fi nite element analysis model has been developed based on the previous experimental results of 7075-T6 four-bolted connections and previous fi nite element analysis procedures related to singe shear bolted connections. The validation of fi nite element analysis method for predicting the ultimate behaviors of 7075- T6 bolted connections was verifi ed through the comparison of test results and analysis results. Additional analyses with extended parameters of end and edge distances were conducted. As a result, strength reduction ratio (up to maximum 19%) by curling was investigated quantitatively and the curling occurrence conditions for end distance and edge distance were presented. In addition, analysis strengths were compared with design strengths by AAA (American Aluminum Association), AISI (American Iron Steel Institute) design specifi cations and proposed equation for 6061-T6 aluminum alloys four-bolted connections. Lastly, revised strength equation was suggested considering the actual fracture mechanism at ultimate state and curling infl uence (strength drop) by bolt bearing action.

MHY451 induces cell cycle arrest and apoptosis by ROS generation in HCT116 human colorectal cancer cells

Hwang, Na Lam,Kang, Yong Jung,Sung, Bokyung,Hwang, Seong Yeon,Jang, Jung Yoon,Oh, Hye Jin,Ahn, Yu Ra,Kim, Do Hyun,Kim, Su Jeong,Ullah, Sultan,Hossain, Mohammad Akbar,Moon, Hyung Ryong,Chung, Hae Young Spandidos Publications 2017 Oncology Reports Vol.38 No.3

<P>Colorectal cancer (CRC) is the third most frequently diagnosed cancer and cause of cancer-related deaths. Despite advancements in conventional therapeutic approaches to CRC, most patients with CRC die of their disease. There is a need to develop novel therapeutic agents for this malignancy. Therefore, the present study aimed to examine the anticancer effects and elucidate the underlying mechanism of MHY451 in HCT116 human colorectal cancer cells. Treatment with MHY451 inhibited cell growth in a time- and concentration-dependent manner. MHY451 increased the accumulation of cell cycle progression at the G2/M phase. This agent decreased the protein level of cyclin B1 and its activating partners, Cdc25c and Cdc2, whereas it increased the cell cycle inhibitor p21WAF/CIP. The induction of apoptosis was observed by decreased viability, cleavage of poly(ADP-ribose) polymerase (PARP), alteration in the ratio of Bax/Bcl-2 protein expression and reduction of procaspase-8 and -9. Pretreatment with Z-VAD-FMK, a pan-caspase inhibitor, inhibited MHY451-induced apoptosis, indicating that apoptotic cell death by MHY451 was mediated through caspases. Moreover, the apoptotic effect of MHY451 was reactive oxygen species (ROS)-dependent, evidenced by the inhibition of MHY451-induced PARP cleavage and ROS generation by N-acetylcysteine-induced ROS scavenging. Taken together, these results demonstrate that MHY451 exerts anticancer effects by regulating the cell cycle, inducing apoptosis through caspase activation and generating ROS. These results suggest that MHY451 has considerable potential for chemoprevention or treatment of CRC or both.</P>

냉간성형 듀플렉스계 스테인리스강(STS329FLD) 용접접합부 모재 블록전단파단 거동

황보경(Hwang, BoKyung),김태수(Kim, TaeSoo) 대한건축학회 2019 大韓建築學會論文集 : 構造系 Vol.35 No.4

Recently, lean duplex stainless steel, STS329FLD with less nickel (reduced to 0.5~1.5%) has been developed as a substitute of austenitic stainless steel (8%~10.5% nickel in STS304) and included in Korean standards (KS). This paper investigates the block shear behavior of cold-formed duplex stainless steel (STS329FLD, nominal plate thickness of 1.5mm) fillet-welded connection with base metal fracture. Main variables are weld lengths in the longitudinal and the transverse directions of applied force ranged from 20mm to 50mm. As a result, specimens failed by typical block shear facture (the combination of gross section tensile fracture and shear fracture or shear yielding) and ultimate strength of the specimens got higher with the increase of weld length. Block shear fracture strengths predicted by current design specifications (KBC2016/AISC2016 and EC3) and existing proposed equations for welded connections by Topkaya, Oosterhof & Driver and Lee et al. were compared with test strengths. KBC2016/AISC2016 and EC3 design specifications underestimated block shear strength of STS329FLD welded connections by on average 24%, 29%, respectively and Oosterhof & Driver, Topkaya and Lee et al’s equations overestimated the ultimate strength of the welded connection by the range of 3% to 44%.

중년 성인의 죽음불안과 죽음수용의 관계: 의미추구·의미발견의 조절효과

황보경(Bokyung Hwang),심예린(Yerin Shim) 충남대학교 사회과학연구소 2022 사회과학연구 Vol.33 No.4

The present study aim to investigate the moderating effect of search for meaning and presence of meaning in the relationship between death anxiety and death acceptance among middle-aged adults based on Wong’s Meaning Management Theory (MMT). A total of 202 middle-aged South Korean adults participated in an online survey which included the Death Anxiety Scale, Death Attitude Profile, and Meaning in Life Questionnaire and demographic questionnaires. Data analysis was conducted using the SPSS 26.0 software and the PROCESS Macro 4.0, Model 1. The main results were as follows: First, death anxiety had a significant negative correlation with death acceptance. Next, the moderating effect of search for meaning in the relationship between death anxiety and death acceptance was significant. However, the moderating effect of presence of meaning between death anxiety and death acceptance was not significant. Based on these findings, practical suggestions and limitations of this study, and directions for future research, are discussed.

Optimization of Large-Scale Expansion and Cryopreservation of Human Natural Killer Cells for Anti-Tumor Therapy

Bokyung Min,Hana Choi,Jung Hyun Her,Mi Young Jung,Hyo-Jin Kim,Mi-young Jung,Eun-Kyoung Lee,Sung Yoo Cho,Yu Kyeong Hwang,Eui-Cheol Shin 대한면역학회 2018 Immune Network Vol.18 No.4

Anti-adipocyte Differentiation Activity and Chemical Composition of Essential Oil from Artemisia annua

Hwang, Dae Il,Won, Kyung-Jong,Kim, Do-Yoon,Yoon, Seok Won,Park, Joo-Hoon,Kim, Bokyung,Lee, Hwan Myung NATURAL PRODUCT COMMUNICATIONS 2016 Natural product communications Vol.11 No.4

Cinnamyl Alcohol, the Bioactive Component of Chestnut Flower Absolute, Inhibits Adipocyte Differentiation in 3T3-L1 Cells by Downregulating Adipogenic Transcription Factors

Hwang, Dae Il,Won, Kyung-Jong,Kim, Do-Yoon,Kim, Bokyung,Lee, Hwan Myung World Scientific 2017 The American journal of Chinese medicine Vol.45 No.4

기술사회의 라이프스타일 기반 스마트 주거 공간디자인에 관한 연구

문보경 ( Bokyung Moon ),김주연 ( Joo Yun Kim ),안진근 ( Jinkeun Ahn ),황용섭 ( Yongseup Hwang ) 한국공간디자인학회 2015 한국공간디자인학회논문집 Vol.10 No.2

(연구배경 및 목적) 주거 공간은 사회, 문화, 환경, 기술적 변화와 상호작용하면서 끊임없이 진화되어 왔으며, 이러한 변화에 인간의 라이프스타일 역시 궤를 같이하여 왔다. 현대의 주거는 디지털 및 정보 기술의 발전에 힘입어 인간과 상호작용하고 새로운 경험을 주는 종합적 공간 시스템으로 구축되어지고 기술은 공간의 다양한 경계를 모호하게 하고 있다. 이는 독자적이고 능동적으로 기능하는 새로운 스마트 주거 공간의 형태로 구체화되고 있다. 인간의 거주와 그 주거공간의 형태적 변화를 예측해 보는 것은 공간디자인에서 매우 중요한 의미를 가진다. 본 연구의 목적은 현대 기술사회에서 인간의 라이프스타일 변화에 따라서 형성되고 변해가는 스마트 주거공간을 현대인의 다양한 라이프스타일 기반으로 특징과 주거유형을 살펴보고 이에 따라 적용할 수 있는 스마트 주거 공간디자인 전략의 방향성을 제시하고자 한다. (연구방법) 첫째, 문헌 고찰을 통하여 산업화 이후 라이프스타일 변화 및 주거생활과 어떠한 상호작용하는지 이해하고 이를 통해 현대인의 라이프스타일에 따른 주거의식을 이해한다. 둘째, 기술 발전에 따라 변해온 주거형태를 이해하고 현재에 이르러 성립된 스마트주거의 유형과 특징을 이해한다. 셋째, 스마트주거의 특징을 바탕으로 공간디자인 취할 수 있는 디자인 전략 틀을 구축하고 이를 관점으로 스마트 주거 환경을 구현한 선행사례를 조사하고 대입하여 분석한다. (결과) 스마트 주거공간은 거주자의 생활패턴에 따른 환경을 조성하고 다양한 구조를 제공한다. 자연소재와 스마트기술의 조화로운 결합이 주는 심미적 친환경 주거를 제공한다. 기존 물리적 공간에 콘텐츠의 유입으로 정보접근성이 용이해지고 자유롭게 정보공유를 통해 장소의 이동 없이 주거 공간 내의 환경을 니즈에 따라 해결 가능한 환경으로 조성한다. 앞으로 스마트주거환경의 편의성을 기대하는 사람들은 더욱 늘어날 것이다. 스마트주거환경이 기술의 관점에서 발전되어 온 만큼 현재는 기술기반의 접근형태가 강하게 나타나고 있는 것이 분명하다. 그러나 기술이 보다 보편화되고 세련되어 지면서 디자인에 대한 감성적 요구가 늘어날 것임은 분명하다. (결론)우리가 가장 중요하게 생각해야 할 것은 공간과 기술의 결합이 아닌 인간, 인간과 공간, 공간과 공간간의 소통이 가장 중요하며 현대인의 라이프스타일 변화에 따른 대응으로 공간에 인간행태가 묻어나는 재현방식으로 구축하여야 한다. 따라서 앞으로 스마트주거 공간디자인의 지속적인 연구가 필요하다. 본 연구에서 다루어진 사례가 한정적이라는 한계를 인정할 수밖에 없지만, 이러한 연구를 통해 스마트 주거공간디자인에 대한 다양한 후속연구를 촉발시키는 계기가 되기를 기대한다. (Background and Purpose) Residential spaces have been evolving continuously as a result of social, cultural, environmental, and technological changes, and human lifestyles have been in sync with these changes. Thanks to advancements in digital and information technology, residential spaces in the modern age are structures characteristic of a complex spatial system that facilitates human interaction and delivers new experiences. Thus, technology blurs the various boundaries of space. Accordingly, a new and smart residential space that functions actively and independently has emerged. Predictions regarding residential spaces and their formative changes have considerable significance in space design. The purpose of this study is to examine the features and types of smart residential spaces that are forming and changing according to changes in human lifestyles in the modern technological society. The directionality in design strategies for such spaces is presented in this paper. (Method) First, a literature review was employed to understand lifestyle changes that occurred after industrialization, their interactions with residential spaces, and modern people’s residential awareness. Second, an investigation was conducted to understand changes in residential forms that have accompanied technological advancement; contemporary types and features of smart residential spaces were also examined. Third, a strategic framework design was established based on the characteristics of smart residences; further, an investigation and analysis of previous cases regarding the smart residential environment were performed. (Results) Smart residential spaces form environments and structures that correspond to the life patterns of residents. An aesthetic and eco-friendly residence comes from a harmonious combination of natural materials and smart technologies. Additions to preexisting physical spaces ensure various information accessibilities; further, changes to residential spaces and environments reflect the need for unlimited sharing of information that does not require moving to a different location. The number of people seeking the conveniences of the smart residential environment is increasing. Furthermore, the smart residential environment requires a stronger technology-based approach. However, as technology becomes generalized and polished, emotional prerequisites associated with designs will definitely increase. (Conclusions) The primary concerns underlying the construction of residential spaces are humans and communications between humans and spaces-not the combination of spaces and technologies. Thus, construction is performed in response to the expansion of human consciousness as a representational method that reflects humans’ behaviors as they pertain to spaces. This study involved the exploration of a limited number of case studies; however, its findings may prompt various follow-up studies on smart residential space design.

Optimization of Large-Scale Expansion and Cryopreservation of Human Natural Killer Cells for Anti-Tumor Therapy

Min, Bokyung,Choi, Hana,Her, Jung Hyun,Jung, Mi Young,Kim, Hyo-Jin,Jung, Mi-young,Lee, Eun-Kyoung,Cho, Sung Yoo,Hwang, Yu Kyeong,Shin, Eui-Cheol 한국조명·전기설비학회 2018 한국조명·전기설비학회 학술대회논문집 Vol. No.

<P>Allogeneic natural killer (NK) cell therapy is a potential therapeutic approach for a variety of solid tumors. We established an expansion method for large-scale production of highly purified and functionally active NK cells, as well as a freezing medium for the expanded NK cells. In the present study, we assessed the effect of cryopreservation on the expanded NK cells in regards to viability, phenotype, and anti-tumor activity. NK cells were enormously expanded (about 15,000-fold expansion) with high viability and purity by stimulating CD3<SUP>+</SUP> T cell-depleted peripheral blood mononuclear cells (PBMCs) with irradiated autologous PBMCs in the presence of IL-2 and OKT3 for 3 weeks. Cell viability was slightly reduced after freezing and thawing, but cytotoxicity and cytokine secretion were not significantly different. In a xenograft mouse model of hepatocellular carcinoma cells, cryopreserved NK cells had slightly lower anti-tumor efficacy than freshly expanded NK cells, but this was overcome by a 2-fold increased dose of cryopreserved NK cells. <I>In vivo</I> antibody-dependent cell cytotoxicity (ADCC) activity of cryopreserved NK cells was also demonstrated in a SCID mouse model injected with Raji cells with rituximab co-administration. Therefore, we demonstrated that expanded/frozen NK cells maintain viability, phenotype, and anti-tumor activity immediately after thawing, indicating that expanded/frozen NK cells can provide ‘ready-to-use’ cell therapy for cancer patients.</P>

Effects of Konan red ginseng intake during endurance training on resting energy metabolism in male mice

( Hye Jung Hwang ),( Ji Su Kim ),( Bokyung Kim ),( Chi Ho Lee ),( Heajung Suh ),( Heayeon Yun ),( Jonghoon Paik ),( Kiwon Lim ) 한국운동영양학회 2013 Physical Activity and Nutrition (Phys Act Nutr) Vol.17 No.1

This study was designed to investigate the effect of red ginseng (RG) intake during 2 weeks of training on the resting energy metabolism in mice. RG (20 mg/kg body weight) were orally administered to 7-week old male ICR mice during 2 weeks of endurance training. The resting metabolic rate for 24h was measured before and after the 2 week experimental periods. The total amount of food intake was significantly higher in the RG group than in the control group (p < 0.05), whereas mean body weight was not different. Oxygen uptake during 24 hours both before and after the experimental session was not different between the two groups. Carbohydrate oxidation and fat oxidation in resting were significantly decreased and increased by endurance training, respectively, but no difference was observed between the two groups. Accordingly. we suggest that red ginseng intake of 20mg/kg body weight during 2 weeks of endurance training may not affect resting energy metabolism (RER) over one day in male mice.