Investigating the Determinants of Customer Satisfaction, Switching Barriers, and Loyalty in the Mobile Telecommunications Service

( Inyoung Cho ),( Yoon C. Cho ) 서암순창장학회 2017 Journal of Marketing Thought Vol.4 No.3

Customer satisfaction, switching barriers, and customer loyalty are significantly important concepts to stakeholders in the mobile telecommunications market because luring new customers is very costly to carriers in a mobile telephone service that has already entered a mature stage, (Kim and Yoon, 2004; Kim, Park, and Jeong, 2004). The purpose of the study is to investigate i) effects of determinants on customer satisfaction and switching barriers, ii) effects of customer satisfaction and switching barriers on loyalty, iii) effects of brand image on loyalty, and iv) effects of customer satisfaction, switching barrier, and brand image on relative attitude and repeat patronage in the mobile telecommunications service. This study conducts an online survey and applies regression analyses. This research provides policy, managerial, and academic implications for the mobile telecommunications service.

Ovastacin: An oolemma protein that cleaves the zona pellucida to prevent polyspermy

Inyoung Kang,Myoungjoo Koo,Hyejin Yoon,Beom Seok Park,Jin Hyun Jun,Jaewang Lee The Korean Society for Reproductive Medicine 2023 Clinical and Experimental Reproductive Medicine Vol.50 No.3

Monospermy occurs in the process of normal fertilization where a single sperm fuses with the egg, resulting in the formation of a diploid zygote. During the process of fertilization, the sperm must penetrate the zona pellucida (ZP), the outer layer of the egg, to reach the egg's plasma membrane. Once a sperm binds to the ZP, it undergoes an acrosomal reaction, which involves the release of enzymes from the sperm's acrosome that help it to penetrate the ZP. Ovastacin is one of the enzymes that is involved in breaking down the ZP. Studies have shown that ovastacin is necessary for the breakdown of the ZP and for successful fertilization to occur. However, the activity of ovastacin is tightly regulated to ensure that only one sperm can fertilize the egg. One way in which ovastacin helps to prevent polyspermy (the fertilization of an egg by more than one sperm) is by rapidly degrading the ZP after a sperm has penetrated it. This makes it difficult for additional sperm to penetrate the ZP and fertilize the egg. Ovastacin is also thought to play a role in the block to polyspermy, a mechanism that prevents additional sperm from fusing with the egg's plasma membrane after fertilization has occurred. In summary, the role of ovastacin in monospermic fertilization is to help ensure that only one sperm can fertilize the egg, while preventing polyspermy and ensuring successful fertilization.

Emerging role of Hippo pathway in the regulation of hematopoiesis

Inyoung Kim,박태호,Ji-Yoon Noh,김완태 생화학분자생물학회 2023 BMB Reports Vol.56 No.8

In various organisms, the Hippo signaling pathway has beenidentified as a master regulator of organ size determination andtissue homeostasis. The Hippo signaling coordinates embryonicdevelopment, tissue regeneration and differentiation, throughregulating cell proliferation and survival. The YAP and TAZ(YAP/TAZ) act as core transducers of the Hippo pathway, andthey are tightly and exquisitely regulated in response to variousintrinsic and extrinsic stimuli. Abnormal regulation or geneticvariation of the Hippo pathway causes a wide range of humandiseases, including cancer. Recent studies have revealed thatHippo signaling plays a pivotal role in the immune system andcancer immunity. Due to pathophysiological importance, theemerging role of Hippo signaling in blood cell differentiation,known as hematopoiesis, is receiving much attention. A numberof elegant studies using a genetically engineered mouse (GEM)model have shed light on the mechanistic and physiologicalinsights into the Hippo pathway in the regulation of hematopoiesis. Here, we briefly review the function of Hippo signalingin the regulation of hematopoiesis and immune cell differentiation.

감성 분석 DB구축을 위한 Online Rating Game

엄인영(Inyoung Aum),윤찬희(Chanhee Yoon),김은이(Eunyi Kim) 한국정보과학회 2015 한국정보과학회 학술발표논문집 Vol.2015 No.6

Effect of Gd infiltration on NiO-CeO₂ anode substrates for intermediate-temperature solid oxide fuel cells

Jang, Inyoung,Kim, Chanho,Kim, Sungmin,Yoon, Heesung Elsevier 2017 Ceramics international Vol.43 No.12

<P><B>Abstract</B></P> <P>In this study, solid oxide fuel cells (SOFCs) were fabricated using cerium oxide in the anode support layer (ASL) instead of gadolinium-doped ceria (GDC). To compensate for the deficiency in ionic conductivity and catalytic activity of CeO<SUB>2</SUB>, a gadolinium nitrate solution was infiltrated in the ASL before sintering at 1450°C. The ohmic and polarization resistance of the cell were reduced upon Gd-nitrate infiltration, which also increased the sinterability of the ASL. However, excessive infiltration was found to degrade the electrochemical properties of the cell. Therefore, the conditions for infiltration were optimized in this study. The peak power density of the cell after Gd-nitrate infiltration was 0.662W, 68% higher than that of the reference cell without Gd-nitrate infiltration.</P>

Interface engineering of yttrium stabilized zirconia/gadolinium doped ceria bi-layer electrolyte solid oxide fuel cell for boosting electrochemical performance

Jang, Inyoung,Kim, Sungmin,Kim, Chanho,Lee, Hyungjun,Yoon, Heesung,Song, Taeseup,Paik, Ungyu Elsevier 2019 Journal of Power Sources Vol.435 No.-

<P><B>Abstract</B></P> <P>La<SUB>0.6</SUB>Sr<SUB>0.4</SUB>Co<SUB>0.2</SUB>Fe<SUB>0.8</SUB>O<SUB>3-δ</SUB> (LSCF) is a promising cathode material for solid oxide fuel cells due to its high oxygen reduction reaction (ORR) activity. A gadolinium-doped ceria (GDC) barrier layer is essential to preventing side reactions between LSCF and an yttrium-stabilized zirconia (YSZ) electrolyte. However, several challenges are associated with the coating of GDC barrier layer on the YSZ electrolyte, including delamination of the GDC layer due to sinterability differences and formation of an insulating layer at a high annealing temperature. In this study, we describe a structure for a newly designed interfacial layer consisting of a GDC barrier layer and a nano-web–structured LSCF thin-film layer (NW-LSCF) through a facile spin-coating method. A dense GDC barrier layer with a thickness of approximately 400 nm was successfully applied to the surface of a YSZ electrolyte without delamination at a low annealing temperature. The high surface area of the NW-LSCF enhanced ORR due to an increased triple-phase boundary length. Cells employing a GDC barrier layer and NW-LSCF interlayer exhibited improved electrochemical performance. Peak power density reached 1.29 W/cm<SUP>2</SUP> at an operating temperature of 550 °C and 2.14 W/cm<SUP>2</SUP> at 650 °C.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Newly designed interfacial layer structure is developed for interfacial engineering. </LI> <LI> Combined structure of GDC barrier layer/NW-LSCF improves electrochemical properties. </LI> <LI> The NW-LSCF enables higher oxygen reduction reaction at lower temperature. </LI> <LI> Results show the possibility of lowering SOFCs operating temperature. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Enhancement of oxygen reduction reaction through coating a nano-web-structured La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ thin-film as a cathode/electrolyte interfacial layer for lowering the operating temperature of

Jang, Inyoung,Kim, Sungmin,Kim, Chanho,Yoon, Heesung,Song, Taeseup Elsevier 2018 Journal of Power Sources Vol.392 No.-

<P><B>Abstract</B></P> <P>Lowering operation temperature of the solid oxide fuel cell is critical to improving its reliability and durability. However, the tradeoff between the operation temperature and the oxygen reduction reaction on the cathode side hinders lowering of the operation temperature. To address this issue, we employ a nano-web-structured La<SUB>0.6</SUB>Sr<SUB>0.4</SUB>Co<SUB>0.2</SUB>Fe<SUB>0.8</SUB>O<SUB>3-δ</SUB> (NW-LSCF) thin-film layer as an interlayer on the cathode side. This thin-film layer enables operating the cell at a low temperature with enhancement of the electrochemical performance by increasing the oxygen-reduction reaction site and is fabricated via a simple spin-coating method. The large surface area of NW-LSCF enables significant improvement in the oxygen reduction reaction by an increased triple-phase boundary. In addition, the adhesion property between the gadolinium-doped ceria electrolyte and cathode is improved by the layer. In an anode-support-type single cell test, the peak power density of the cell with NW-LSCF is 0.57 W/cm<SUP>2</SUP> at 550 °C, which is an approximately 63% improvement compared to that of the cell without NW-LSCF. Moreover, the value is comparable to the peak power density of the cell without NW-LSCF operating at 600 °C. This finding suggests the possibility of lowering the operating temperature of the solid oxide fuel cell by introducing NW-LSCF into the cell.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A NW-LSCF was fabricated via a simple spin-coating method. </LI> <LI> The NW-LSCF was introduced between the cathode and electrolyte layer. </LI> <LI> The large surface area structure enables higher oxygen reduction reaction. </LI> <LI> Results show the possibility of lowering SOFCs operating temperature. </LI> </UL> </P>

A 0.13-μm CMOS Multi-Divider for 100 MHz ~ 1 GHz Frequency Synthesizer

최인영(Inyoung Choi),이정철(Jungcheol Lee),윤제형(Jehyung Yoon),서희송(Heesong Seo),김범만(Bumman Kim) 대한전자공학회 2010 대한전자공학회 학술대회 Vol.2010 No.6

A Wideband Digital RF Receiver Front-End Employing a New Discrete-Time Filter for m-WiMAX

Heesong Seo,Inyoung Choi,Changjoon Park,Jehyung Yoon,Bumman Kim IEEE 2012 IEEE journal of solid-state circuits Vol.47 No.5

<P>A wideband digital RF receiver front-end employing a discrete-time (DT) filter is presented for application to m-WiMAX (WiBro). By employing a sampling mixer and a DT filter, the receiver operates in the charge domain. In addition to the flexibility of the DT filter, the new non-decimation finite impulse response (NDF) filter can be cascaded to a conventional finite impulse response (FIR) filter without the decimation effect. Thus, we can easily increase the order of the <I>sincn</I> function-type filtering response and the signal processing bandwidth. The FIR filter is also modified to reduce the noise and the number of required clock signal. Because of the new filter configuration, clock signals can be shared by the FIR filter and NDF filter and the clock generator circuit can be simplified. The designed receiver front-end is implemented using an IBM 0.13-μm RF CMOS process. The fabricated chip satisfies the m-WiMAX specification of an 8.75 MHz channel bandwidth and the total system current dissipation is 26.63 mA from a 1.5-V supply voltage.</P>

South Korea’s Response to COVID-19 Using ICT

Sang-chul Yoon,Jong-wook Lee,Inyoung Kim,Sang-eun Roh 한국국제협력단 2020 연구보고서 Vol.- No.-

The coronavirus has quickly developed into a pandemic since its outbreak, posing a grave threat to the global community. Efforts to curb the spread of the pandemic are made across all sectors of the society, and the critical need for international cooperation to combat COVID-19 is even further emphasized. Hence, any case of effective response to COVID-19 holds useful lessons for other countries. This study reviews and analyzes South Korea’s response to COVID-19 utilizing information and communication technology (ICT). South Korea had to deploy effective epidemic-preventive measures early on in the pandemic as it experienced its COVID-19 peak before most other countries. The country implemented accurate and extensive ‘testing’, ‘tracing’ and ‘treatment’, and communicated with the public upon its principles of ‘rapid, accurate and transparent’ information- sharing. In doing so, ICT-based centralized information systems including the Smart Quarantine System, Epidemiological Investigation Support System and Patient Information Management System were utilized, which resultingly flattened the infection curve. Furthermore, the government disclosed data collected from its centralized information system in user-friendly forms by engaging with the private sector. One outcome of such efforts was stabilized supply and demand for face masks, a necessity good for securing individual health. Such aforementioned technologies served to advance traditional epidemic response measures, enhancing the procedural speed and accuracy and tracing coverage. This study aims to share South Korea’s experience in responding to COVID-19 as it offers useful and practicable insights for countries interested in making greater use of ICT to tackle the COVID-19. While current knowledge exchange-dialogues are somewhat limited in producing widely applicable solutions due to context- specific factors, it is anticipated that an accumulation of shared experiences will strengthen the global community’s COVID-19 response capabilities.