• Anxiety and mood
• /
• v.6 no.1
• /
• pp.65-70
• /
• 2010

Objectives : Indirect contact with trauma may occur when a person empathically listens to detailed descriptions, exposing the person to intense emotional pain from trauma victims. Although less severe than direct trauma, indirectly traumatized persons may experience the same fear, rage, and despair as direct trauma victims. This phenomenon has been variously termed vicarious trauma, traumatic countertransference, burnout, compassion fatigue, and secondary traumatic stress. Using a psychiatric symptoms questionnaires, this study investigated the effects of indirect exposure to co-worker's trauma on the mental health of firefighters who had not directly experienced traumatic events in the previous year. Methods : We administered self-report questionnaires, such as the Impact of Event Scale-Revised (IESR) and Alcohol Use Disorder Identification Test (AUDIT), to firefighters working at two fire stations in a metropolitan city. We analyzed 188 of 232 collected surveys, after excluding falsely entered data (28 cases) and questionnaires by directly-traumatized victims (16 cases). Results : Alcohol consumption and posttraumatic stress disorder (PTSD) symptoms, as determined by the AUDIT and IES-R, were significantly higher in the indirectly-traumatized group. The ratio of high-risk members scoring higher than 23 in IES-R was larger in the indirectly traumatized group, although this was not statistically significant. Conclusion : Alcohol consumption was significantly higher in the indirectly traumatized group. This group also included more members at high risk for PTSD. Further research, with a larger group of indirectly traumatized firefighters and ongoing investigation of PTSD development and other psychiatric symptoms, is needed.

• Current Optics and Photonics
• /
• v.2 no.5
• /
• pp.474-481
• /
• 2018

We propose a polarization phase-shifting technique to investigate the thickness of $Ta_2O_5$ thin films deposited on BK7 substrates, using a modified Sagnac interferometer. Incident light is split by a polarizing beam splitter into two orthogonal linearly polarized beams traveling in opposite directions, and a quarter-wave plate is inserted into the common path to create an unbalanced phase condition. The linearly polarized light beams are transformed into two circularly polarized beams by transmission through a quarter-wave plate placed at the output of the interferometer. The proposed setup, therefore, yields rotating polarized light that can be used to extract a relative phase via the self-reference system. A thin-film sample inserted into the cyclic path modifies the output signal, in terms of the phase retardation. This technique utilizes three phase-shifted intensities to evaluate the phase retardation via simple signal processing, without manual adjustment of the output polarizer, which subsequently allows the thin film's thickness to be determined. Experimental results show that the thicknesses obtained from the proposed setup are in good agreement with those acquired by a field-emission scanning electron microscope and a spectroscopic ellipsometer. Thus, the proposed interferometric arrangement can be utilized reliably for non-contact thickness measurements of transparent thin films and characterization of optical devices.

• Journal of the Korean Geophysical Society
• /
• v.5 no.1
• /
• pp.19-27
• /
• 2002

Geophysical surveys(self-potential, electromagnetic, electrical resistivity, and seismic refraction methods) were performed to delineate the flow channel of leachate from a AMD (acid mine drainage) by correlating the anomalies to geochemical characteristics at an abandoned mine (Jangpoong mine). The geophysical responses attempted to be correlated with water sample analysis data(pH, EC, heavy metals, ${SO_4}^{-2}$). Electrical dipole-dipole resistivity sections represent the low-resistivity zone trending northwest, which indicates the leachate flow by AMD along the contact of the mine waste rock dump and the bedrock. From the overall points of geophysical and geochemical anomalies, it is summarized that the flow channel of leachate by AMD can be successfully imaged with composite interpretations on the geophysical and geochemical studies.

• The Journal of Korean Institute of Information Technology
• /
• v.16 no.12
• /
• pp.31-40
• /
• 2018

We designed and implemented the attachable smart adapter for the general management of each company's agricultural machine regardless of whether it is equipped with a CAN (Controller Area Network) module. The smart adapter consists of a main board (Raspberry Pi3B), which operates agricultural machine's management software in Linux environment, and a self-developed interface board for power adjustment and status sensing. For the status monitoring, a sensing interface using a serial input was defined between the smart adapter and the sensors of the agricultural machine, and the state diagram of the agricultural machine was defined for diagnosis. We made a panel to simulate the sensors of the agricultural machine using the switch's on/off contact point, and confirmed the status monitoring and diagnostic functions by inputting each state of the farm machinery from the simulator panel.

• Molecules and Cells
• /
• v.44 no.5
• /
• pp.310-317
• /
• 2021

Cluster of differentiation 1 (CD1) is a family of cell-surface glycoproteins that present lipid antigens to T cells. Humans have five CD1 isoforms. CD1a is distinguished by the small volume of its antigen-binding groove and its stunted A' pocket, its high and exclusive expression on Langerhans cells, and its localization in the early endosomal and recycling intracellular trafficking compartments. Its ligands originate from self or foreign sources. There are three modes by which the T-cell receptors of CD1a-restricted T cells interact with the CD1a:lipid complex: they bind to both the CD1a surface and the antigen or to only CD1a itself, which activates the T cell, or they are unable to bind because of bulky motifs protruding from the antigen-binding groove, which might inhibit autoreactive T-cell activation. Recently, several studies have shown that by producing T_H2 or T_H17 cytokines, CD1a-restricted T cells contribute to inflammatory skin disorders, including atopic dermatitis, psoriasis, allergic contact dermatitis, and wasp/bee venom allergy. They may also participate in other diseases, including pulmonary disorders and cancer, because CD1a-expressing dendritic cells are also located in non-skin tissues. In this mini-review, we discuss the current knowledge regarding the biology of CD1a-reactive T cells and their potential roles in disease.

• The Journal of the Korea Contents Association
• /
• v.22 no.7
• /
• pp.253-263
• /
• 2022

This study examined the relationships between socio-demographic background variables, parent-child differentiation, marital stability, and psychological well-being in 382 eco-boomer married women (born in 1979-1992) whose mothers were born in 1955-1963. As a result, the higher the average monthly contact frequency with the mother, the greater the intimacy (connectivity) with the mother. The higher the number of years of marriage, the lower the marriage stability, the higher the education level, and the higher the average household income were related to the higher the self-acceptance. In addition, compared to women in single-income families, married women who receive help raising their children from their mothers did not form reliable relationships with others or show satisfaction compared to women who do not receive the assistance. Those who were well connected with their mother (or had high intimacy) had higher marriage stability, and those with higher marriage stability had higher psychological well-being. They also had better relationships with other people when married women had a higher level of parent-child differentiation.

• Korean Journal of Materials Research
• /
• v.32 no.11
• /
• pp.508-514
• /
• 2022

Piezoelectric composite films which are enabled by inorganic piezoelectric nanomaterials-embedded polymer, have attracted enormous attention as a sustainable power source for low powered electronics, because of their ease of fabrication and flexible nature. However, the absorption of applied stress by the soft polymeric matrices is a major issue that must be solved to expand the fields of piezoelectric composite applications. Herein, a flexible and porous piezoelectric composite (piezoelectric sponge) comprised of BaTiO₃ nanoparticles and polydimethylsiloxane was developed using template method to enhance the energy conversion efficiency by minimizing the stress that vanishes into the polymer matrix. In the porous structure, effective stress transfer can occur between the piezoelectric active materials in compression mode due to direct contact between the ceramic particles embedded in the pore-polymer interface. The piezoelectric sponge with 30 wt% of BaTiO₃ particles generated an open-circuit voltage of ~12 V and a short-circuit current of ~150 nA. A finite element method-based simulation was conducted to theoretically back up that the piezoelectric output performance was effectively improved by introducing the sponge structure. Furthermore, to demonstrate the feasibility of pressure detecting applications using the BaTiO₃ particles-embedded piezoelectric sponge, the composite was arranged in a 3 × 3 array and integrated into a single pressure sensor. The fabricated sensor array successfully detected the shape of the applied pressure. This work can provide a cost-effective, biocompatible, and structural strategy for realizing piezoelectric composite-based energy harvesters and self-powered sensors with improved energy conversion efficiency.

• Journal of the Semiconductor & Display Technology
• /
• v.21 no.1
• /
• pp.148-154
• /
• 2022

As the 4th industrial age approaches, the demand for semiconductors is increasing enough to be used in all electronic devices. At the same time, semiconductor technology is also developing day by day, leading to ultraprecision and low power consumption. Semiconductors that keep getting smaller generate heat because the energy density increases, and the generated heat changes the shape of the semiconductor package, so it is important to manage. The temperature change is not only self-heating of the semiconductor package, but also heat generated by external damage. If the package is deformed, it is necessary to manage it because functional problems and performance degradation such as damage occur. The package burn in test in the post-process of semiconductor production is a process that tests the durability and function of the package in a high-temperature environment, and heat dissipation performance can be evaluated. In this paper, we intend to review a new material formulation that can improve the performance of the adapter, which is one of the parts of the test socket used in the burn-in test. It was confirmed what characteristics the basic base showed when polyamide, a high-molecular material, and alumina, which had high thermal conductivity, were mixed for each magnification. In this study, functional evaluation was also carried out by injecting an adapter, a part of the test socket, at the same time as the specimen was manufactured. Verification of stiffness such as tensile strength and flexural strength by mixing ratio, performance evaluation such as thermal conductivity, and manufacturing of a dummy device also confirmed warpage. As a result, it was confirmed that the thermal stability was excellent. Through this study, it is thought that it can be used as basic data for the development of materials for burn-in sockets in the future.

• Korean Journal of Social Welfare Studies
• /
• v.41 no.4
• /
• pp.345-368
• /
• 2010

The purpose of this study is to develop the School Multicultural Climate(SMC) scale for students and to evaluate its reliability and validity. This study comprises of both qualitative and quantitative research. Preliminary items were developed based on the theoretical literature and interviews with students. The scale was evaluated with students in grades 4 through 6 in the seven elementary schools. Exploratory factor analysis was determined that the scale was composed of four components: Equal Status, Mutual Cooperation, Friendly Relations, Supportive Norms. The scale demonstrated that Cronbach's alpha=.943 for the internal consistency of total items. And the standard error of the measurement, another way of evaluating reliability, was 3.33. Criteria-related validity was evaluated by showing that the differences of the students' recognition of the school multicultural climate level, which depend on the availability of the multiculture-related policy, was statistically significant. The correlation analysis for the convergent validity was performed with the theoretically related variables such as self esteem and school adjustment. It was found that the SMC scale was a reliable and valid measure for evaluating the multicultural climate level of elementary school.

• Women's Health Nursing
• /
• v.29 no.1
• /
• pp.44-54
• /
• 2023

Purpose: Uncertainty and restrictions on daily life have increased fear, stress, and depression during the coronavirus disease 2019 (COVID-19) pandemic. Depression is the most common mental health problem in pregnant women. The purpose of this study was to evaluate the levels of fear and stress related to COVID-19 experienced by pregnant women, as well as their levels of depression, and to examine the factors associated with depression during pregnancy. Methods: This was a cross-sectional, correlational study conducted among 153 pregnant women who visited a maternity hospital in Busan, South Korea. A self-reported questionnaire was used for data collection from December 18, 2021 to March 8, 2022. Data were analyzed using descriptive statistics, the independent t-test, one-way analysis of variance, Pearson correlation coefficients, and multiple regression. Results: Pregnant women experienced a moderate level of fear related to COVID-19, with an average score of 21.55±4.90. The average score for depression during pregnancy was 14.86±11.10, with 50.3% of the participants experiencing depression (≥13). The factors associated with depression during pregnancy were fear of COVID-19, contact with a confirmed case of COVID-19, being in the third trimester of pregnancy, high stress levels due to difficulties experienced from social distancing measures, and unintended pregnancy. These five statistically significant factors explained 35.0% of variance in depression during pregnancy. Conclusion: Considering the prevalence of depression in pregnant women during the COVID-19 pandemic, it is necessary to develop interventions to reduce anxiety by providing correct information and alleviating the stress of social distancing.