• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.40 no.1
• /
• pp.24-36
• /
• 2003

The digital mobile communication will be developed till getting multimedia service in anyone, any where, any time. Theses requiring items are going to be come true via IMT-2000 system. Transmitting signal bandwidth of IMT-2000 system is 3 times as large as IS-95 system. That is mean peak to average of signal is higher than IS-95A system. So we have to design it carefully not to effect in adjacent channel. HPA(High Power Amplifier) located in the end point of system is operated in 1-㏈ compression point(Pl㏈), then it generates 3rd and 5th inter modulation signals. Theses signals affect at adjacent channel and RF signal is distorted by compressed signal which is operated near by Pl㏈ point. Then the most important design factor is how we make HPA having high linearity. Feedback, Pre-distorter and Feed-forward methods are presented to solve theses problems. Feed-forward of these methods is having excellent improving capacity, but composed with complex structure. Generally, Linearity and Efficiency in power amplifier operate in the contrary, then it is difficult for us to find optimal operating point. In this paper we applied algorithm which searches optimal point of linear characteristics, which is key in Power Amplifier, using minimum current point of error amplifier in 1st loop. And we made 2nd loop compose with new structure. We confirmed fabricated LPA is operated by having high linearity and minimum current condition with ACPR of -26 ㏈m max. @ 30㎑ BW in 3.515㎒ and ACLR of 48 ㏈c max@${\pm}$㎒ from 1W to 40W.

• Journal of fish pathology
• /
• v.20 no.2
• /
• pp.119-127
• /
• 2007

Phosphoinositide-specific phospholipase Cδ (PLCδ) plays an important role in many cellular responses and is involved in the production of second messenger. The present study was conducted to characterize the catalytic and regulatory properties of the PLCδ of Misgurnus mizolepis (ML-PLCδ). The ML-PLCδ gene was cloned and expressed under according to the method of the previous report (Kim et al., 2004), and its recombinant protein was purified by successive chromatography using Ni2+-NTA affinity column. The recombinant ML-PLCδ showed a concentration-dependent PLC activity to phosphatidylinositol 4,5-bisphosphate (PIP2) or phosphatidylinositol (PI). Its activity was absolutely Ca2+-dependence, which was similar to mammalian PLCδ isozymes. The Ca2+ concentration yielding maximal activation of ML-PLCδ was 100 μM. However, the activity was decreased interestingly by a polyamine, such as spermine and spermidine. In vitro assay using cholate-micelle cell, ML-PLCδ activity was inhibited in dose-dependent manner by sphinogosine but increased by phosphocholine . In the lipid-binding assay, ML-PLCδ was strongly bound to LPA, PI(3)P, PI(4)P, PI(5)P, PI(3,5)P2, PI(4,5)P2, PI(3,4,5)P3 and PA, but it showed the low affinity to S1P, PI(3,4)P2 and PS. Taken together our results, it is suggested that the general catalytic and regulatory properties of ML-PLCδ are similar with those of mammalian PLCδ1 isozymes, but the N-terminal extended piscine phospholipase Cδ1 (ML-PLCδ) might reflect some distinctions in regulatory properties and inositol-lipid binding specificity between piscine ML-PLCδ and mammalian PLCδ isozymes.

• Korean Journal of School Psychology
• /
• v.17 no.2
• /
• pp.223-241
• /
• 2020

The purpose of this study was to explore the latent profiles of social achievement goals and to investigate the differences in peer status (perceived popularity, social preference) and aggression (overt, relational, cyber) among those profile groups. Social achievement goals and cyber aggression data was acquired through self-reporting, and perceived popularity, social preference, and overt and relational aggression were assessed through peer nomination. Applying the latent profile analysis(LPA) to 1,239 elementary school students, three distinct groups of social achievement goals were identified: a development-oriented achievement goal group, an average social goal group, and a overall-high social achievement goal group. Using logistic regression analysis, the relationships between the latent group, peer status, and aggression were examined. The result indicated that the higher the social preference, the lower the probability of belonging to the 'overall-high social achievement goal group'. And the higher the cyber aggression, the lower the probability of belonging to the 'development-oriented achievement goal group'. In addition, the higher the relational aggression of the second time, the higher the probability of belonging to the 'overall-high social achievement goal group' as compared to the 'average social goal group'.

• 한국노년학
• /
• v.39 no.1
• /
• pp.145-167
• /
• 2019

The purpose of this study is to examine the solidarity types between parents-children and to verify whether the types of solidarity relationships are directly related to life satisfaction of older adults. To achieve this, 2,072 Korean elderlies from proportional stratified sample were participated, and the data was divided into urban and rural area where respondents live in. The Latent Profile Analysis(LPA), multiple regression analysis were mainly used for data analysis. The results of the study were as follows: The major findings are following. Patterns of parental bond among urban and rural elderly were classified into three(urban) and two(rural) patterns. For the effect of each parental bonding pattern on life satisfaction, positive effect of parental bond was found only in urban dwellers. In other words, for older people in rural areas, parental bond did not significantly affected on life satisfaction. However, elderly in rural area showed non-familial factor based relationship, such as social capital(community trust, social cohesion, and social support), was influenced their life satisfaction rather than relationship with children. Finding from the study highlight political and practical implications for improving life satisfaction for the elderly.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.4
• /
• pp.145-155
• /
• 2020

Since Campbell (1990) proposed multidimensionality of job performance, unlike the single structure of traditional job performance, it has been largely classified as task performance, contextual performance, and counterproductive work behavior. The objective of this study is to validate the threecriteria currently considered major aspects of job performance, to identify different types of performance based on three dimensions, and to compare the power of personality factors among performance types. A total of 681 employees working at various organizations participated in an on-line survey. The survey included boththe exploratory and confirmatory factor analyses. A 3-factor job performance model consisting of three dimensions was also included. The relationships between performance dimensions and personality factors differedby dimensions of performance, supporting the validity of the 3-factor structure of performance.The results of the Latent Profile Analysis identified four types of performance: exemplary, moderately conscientious moderate, and conscientious, butlow.. The Multinomial logistic regression analysis showed each type differed significantly according to the predictors of personality variables. In conclusion, implications and limitations of the study were noted.

• Korean Journal of Culture and Social Issue
• /
• v.28 no.3
• /
• pp.483-512
• /
• 2022

This study examined the patterns of coping strategies among Koreans during the early stage of the COVID-19 pandemic, explored the influence of demographic information (gender, age, economic level, household type), along with the unusual experiences due to COVID-19 (fear, stress of COVID, constraints of routine, income risk) on the classification of subclasses, and analyzed the latent profile differences in psychological wellbeing (life satisfaction, depression, and anxiety). An online survey was conducted among Korean Adults(n=600) between April 13, 2020 and 21, when WHO declared COVID-19 a global pandemic and Daegu as well as Gyeongsangbuk-do was nominated as a special disaster zone. First, Latent Profile Analysis (LPA) was used to identify subclasses of coping strategies and results suggested that the 4-class model had the best fit. Second, Class memberships were predicted by gender, age, economic level, as well as fear, stress, constraints of routine, and income risk, among the unusual experiences due to COVID-19. Finally, there are differences in psychological wellbeing among latent profiles. 'High level of adaptive coping group 3' showed the highest level of life satisfaction, 'Adaptive-maladaptive coping group 4' showed the highest level of depression, anxiety. Implications and suggestions are discussed based on the study results.

• Korean Journal of Culture and Social Issue
• /
• v.25 no.4
• /
• pp.325-351
• /
• 2019

The present study examined patterns of co-occurrence between DSM-5 posttraumatic stress disorder(PTSD) symptoms and posttraumatic growth(PTG) among Korean populations(n= 860). Latent profile analysis was used to identify subclasses and suggested that the 3-class model fit best: (1) Low PTSD/Mild PTG group (2) Low PTSD/High PTG group; (3) High PTSD/High PTG group. Class membership was predicted by demographic variables, social isolation, and frequency of traumatic experiences. Classes also differed with respect to self-destructive behaviors(binge eating, non-suicidal self-injury, and problem drinking). These findings contribute to future research about the coexisting patterns of PTSD and PTG, and to identify high-risk individuals who suffer from trauma-related problems in clinical practice.

• Clinical and Experimental Pediatrics
• /
• v.46 no.1
• /
• pp.67-75
• /
• 2003

Purpose : Intravascular stent implantation for the treatment of postoperative branch pulmonary artery(PA) stenosis has been used successfully. However, the cross sectional area of contralateral branch PA does not regress in spite of the successful dilation of the stenotic branch PA after stent implantation. We analyzed the morphologic and hemodynamic factors on the size of branch PA after successful stent implantation. Methods : The subjects in our study were 23 children who had undergone stent implantaion from Jan. 1995 to Jul. 2002 in the Division of Yonsei Pediatric Cardiology. We evaluated the cross sectional area index(CSAI) of branch PA before and after stent implantation at follow-up catheterization. We also investigated factors such as residual pulmonary stenosis, pulmonary regurgitation(PR), systolic pressure of right ventricle, and lung perfusion scan. Results : The CSAI of the RPA without stenosis changed from mean $238{\pm}17mm^2/BSA$ to mean $249{\pm}20mm^2/BSA$(P=0.47), but didn't regress. The CSAI of the LPA with stenosis was increased effectively by stent implantation from the mean $102{\pm}12mm^2/BSA$ to mean $125{\pm}11mm^2/BSA$(P< 0.05). At follow up after stent implantation, the CSAI of PA is correlated with the residual PR fraction after stent implantation. Conclusion : In a group with increased residual PR, CSAI of RPA was found to be significantly increased between the pre- and post-stages of stent implantation. So, we suspect that the pulmonary regurgitation remaining after right ventricle outlet tract(RVOT) dilatation surgery is correlated with the increase in CSAI of RPA.

• Therapeutic Science for Rehabilitation
• /
• v.10 no.2
• /
• pp.75-93
• /
• 2021

Objective : The aim of this study was to identify subgroups of older adults with respect to their lifestyle patterns and examine the characteristics of each subgroup in order to provide a basic evidence for improving the health and quality of life. Methods : This cross-sectional study was conducted in South Korea. Community-dwelling older adults (n=184) above the age of 65 years were surveyed from April 2019 to May 2019. This study used latent profile analysis to examine the subgroups. Chi-squared (χ²) and multinomial logistic regression measures were then used to analyze individual characteristics and influencing factors. Results : The pattern of physical activity which is one of the lifestyle domains in elderly was categorized into three types: 'passive exercise type (31.1%)', 'low intensity exercise type (54.5%)', and 'balanced exercise type(14.5%)'. Activity participation was divided into three patterns: 'inactive type (12%)', 'self-management type (61%)', and 'balanced activity participation type (27%)'. In terms of nutrition, there were only two groups: 'overall malnutrition type (13.5%)' and 'balanced nutrition type (86.5%)'. Furthermore, as a result of the multinomial logistic regression analysis to understand the effects of lifestyle types on the health and quality of life of the elderly, it was confirmed that the health and quality of life were higher in those following an active and balanced lifestyle. In addition, gender, education level and residential area were analyzed as predictive factors. Conclusion : The health and quality of life of the elderly can be improved when they have balanced lifestyle. Therefore, an empirical and policy intervention strategy should be developed and implemented to enhance the health and quality of life of the elderly.