Ethylene-responsive factors (ERFs) are important plant transcription factors (TFs) that regulate plant responses against various abiotic stresses. However, little information of ERF genes involved in abiotic stress is available in petunia (Petunia ×hybrida). In this study, a petunia ERF gene, PhERF039, was cloned and functional analysis was performed. The quantitative PCR analysis revealed that PhERF039 was induced at the early stage of water deficit stress. Under-expression of PhERF039 (UE) exhibited rosette growth habit, higher number of branches, and delayed flowering compared to the wild type (WT). The UE petunia was evaluated under various volumetric water contents (θ): 0.25, 0.15, 0.10, or 0.05 m3·m-3 using an automated irrigation system. Transgenic plants did not delay plant wilting, but the θ for UE reached to the set point later than that for WT. A lower stomatal conductance was observed in UE than WT under all treatments. These results suggested that PhERF039 could be involved in plant responses under water deficit by regulating stomatal movements as well as branching pattern and flower development.

Sweetpotato (Ipomoea batatas L.) is a globally important food crop that is susceptible to infestation with the root-knot nematode, Meloidogyne incognita, which causes substantial crop losses. Previous transcriptomic and proteomic analyses identified several genes that displayed differential expression patterns in susceptible and resistant cultivars in response to root-knot nematode (RKN) infection. As a result of previous study, RKN infection was confirmed in the RKN-susceptible sweetpotato cultivar Yulmi. Transcriptome analysis confirmed that among the genes that respond in this process, there are many genes related to ethylene biosynthesis. Therefore, in this study, we focused on the ACC oxidase (ACO) gene, the final enzyme of ethylene biosynthesis, and analyzed the expression patterns under various abiotic stress conditions. Using transcriptome data from our previous study, various expression changes in the four ACO genes used in this study were confirmed during RKN infection. The expression of G25011|TU41034 decreased during RKN infection compared to the untreated control, while the expression of G31097|TU51009, G28360|TU46486, and G15447|TU25395 genes increased in the early stages of RKN infection. Expressions of four ACO genes in leaves of sweetpoato were investigated under abiotic stress conditions such as wounding, high salinity, dehydration, and low temperature stress treatment. Expression of the G25011|TU41034 was significantly increased under abiotic stress conditions except low temperature. G31097|TU51009 was hardly expressed under abiotic stress conditions. Although the expression pattern of G28360|TU46486 and G15447|TU25395 was slightly different depending on the type of abiotic stress, an overall increase in expression was observed. It is expected that this study will be used as basic data on how ethylene biosynthesis responds not only to nematode infection but also to various abiotic stress conditions and will be helpful in functional studies of various crops.

PURPOSES : Concrete, which is a construction material, is the most widely used compression material; however, unlike steel, it exhibits nonlinear material characteristics. Therefore, to examine the behavior of structures under the nonlinear conditions of concrete materials, one must select an appropriate numerical-analysis technique and a reasonable material model. When performing the nonlinear numerical analysis of a structure using general-purpose structural analysis software, the stress–strain curve or the Mohr–Coulomb failure criterion is typically employed to consider the nonlinear material characteristics. In this study, an efficient nonlinear numerical analysis is conducted by defining the stress–strain curves and Mohr–Coulomb parameters applicable to Strand7 to examine and design the stability of reinforced concrete structures. METHODS : This study was conducted by improving existing data. Based on the tensile region of the concrete stress–strain curve presented in a simple shape and the results of the splitting test, the proposed Mohr–Coulomb parameter was improved based on regulations stipulated in the design standards of concrete structures. The characteristics and usability of the improved material models were examined using concrete splitting tensile and bending models. RESULTS : A yield area distribution similar to that of the reference data is obtained when the Mohr–Coulomb material model is used in the numerical analysis of the concrete splitting tension, thus confirming the validity of the model. In the Mohr–Coulomb material model, nonlinear resistance continues even after the maximum reaction force occurs. However, when the stress–strain curve material model is applied, at the moment the maximum reaction force occurs, the material yields and begins to be damaged. In addition, by applying the Mohr–Coulomb material model to the bending numerical-analysis model, the magnitude of stress in the tensile region from the initial stage exceeds the yield stress defined in the stress–strain curve. CONCLUSIONS : Based on a series of examples, the usability of the proposed concrete stress–strain curve and Mohr–Coulomb parameters is confirmed. However, to obtain numerical-analysis results that are consistent with the nonlinear behavior of actual structures, nonlinear testing of reinforced concrete structures shall be conducted and material models shall be improved.

본 논문에서는 전산점근해석기법을 사용하여 복합재료 보에 대한 경계층 해를 계산하고, ANSYS 결과와 비교 검증하였다. 경계층 해는 내부해와 순수 경계층 효과의 합으로 표현되기 때문에, 내부 및 경계층에 대한 수학적으로 엄밀한 정식화를 요구한다. 전산점근 해석기법은 수학적으로 매우 강력한 기법으로, 이러한 문제에 유용하다. 그러나 경계층과 내부 해들의 연결을 시키기 쉽지 않은데, 본 연구에서는 가상일의 원리를 통해 생브낭의 원리와 내부 및 경계층 문제를 체계적으로 분리하였다. 경계층 해는 팝코비치-패들 고유 벡터를 계산하여, 실수부와 허수부 벡터들의 선형 조합으로 표현하고, 내부 해의 워핑 함수들을 보상할 수 있도록 최소오차 자승법을 적용하였다. 계산된 해들은 2차원 유한요소 해석 결과와 비교하여 정성적일 뿐만 아니라 정량적으로도 잘 일치하는 결과를 얻었다.

본 연구는 관수조건에 따른 지피식물의 생육특성을 파악하고 수분 스트레스 후 생육 회복력을 평가하 기 위하여 수행되었다. 지피식물로 많이 사용되는 초본류 4종을 대상으로 피복의 목적을 달성할 수 있 는 적정 식재간격을 도출하였으며, 또한 관수처리 유형에 따른 생육 및 피복률의 변화를 분석하였다. 식물마다 피복효과를 달성하기 위한 적정 식재간격에 차이가 있었다. 돌단풍은 30～35cm, 송엽국은 30～40cm간격, 꽃잔디는 40cm이상, 돌나물은 20cm미만의 식재간격이 효과적이다. 관수처리에 따른 생육특성을 분석한 결과 관수가 지속적으로 이루어지면 초장이 길지만 처리기간 동안 생육의 변화는 거의 없었다. 피복률은 관수처리와 식물에 따라 차이가 있다. 송엽국과 돌단풍은 무관수 20일 후 관수가 이루어지면 피복률도 회복되었으며, 꽃잔디는 관수가 이루어지고 나서 시간이 경과된 후에 피복률을 회복하였다. 피복이 전체적으로 이루어진 이후에는 토양 수분부족에 의한 피복률의 변화가 거의 없었 으나 피복 초기에 수분이 공급되지 않으면 피복에 어려움이 있다. 꽃잔디, 송엽국, 돌단풍은 일정기간 무관수가 지속되더라도 다시 관수가 이루어지면 회복이 될 수 있다. 즉 식물관리에 있어서 종 마다 차이 는 있으나 관수관리가 중요하며, 일정기간 무관수 후 관수가 이루어지면 생육이 회복될 수 있다.

In order to investigate the optimum condition of the autofrettage process for the diesel engine fuel injection pipe, different values of autofrettage pressure, pressure rising time, pressure holding time, and repetition of autofrettage process were applied. Autofrettage was performed by applying the hydrostatic internal pressures of 604MPa, 535MPa, 500MPa on the fuel injection pipe, corresponding to theoretical 50%, 30%, and 20% overstrain levels, respectively. The autofrettage residual stresses in the injection pipe were experimentally determined by using X-ray diffractometer. As the overstrain level increased, the magnitude of compressive residual stress at the bore increased. It was found that the rising time to reach the autofrettage pressure, holding time at the autofrettage pressure, and repeated application of the autofrettage pressure on the pipe had no significant influence on the residual stress distributions.

This paper reports the results of an experimental examination using X-rays to test annealing materials for lapped bearing steel (STB2), to confirm the validity of the weighted averaging analysis method. The distribution behavior for the sin diagram and the presence or absence of differences in the peak method, half-value breadth method, and centroid method were investigated. When lapping the annealed bearing steel (STB2) material, a residual stress state with a non-directional steep gradient appeared in the surface layer, and it was found that the weighted averaging analysis method was effective. If there is a steep stress gradient, the sin diagram is curved and the diffraction intensity distribution curve becomes asymmetric, resulting in a difference between the peak method, half-value breadth method, and centroid method. This phenomenon was evident when the stress gradient was more than 2~3 kg/mm2/μm. In this case, if the position of the diffraction line is determined using the centroid method and the weighted averaging analysis method is applied, the stress value on the surface and the stress gradient under the surface can be obtained more accurately. When the stress gradient becomes a problem, since the curvature of the sin diagram appears clearly in the region of sin > 0.5, it is necessary to increase the inclination angle  as much as possible. In the case of a lapping layer, a more accurate value can be obtained by considering  in the weighted averaging analysis method. In an isotropic biaxial residual stress state, the presence or absence of  can be determined as the presence or absence of strain for sin≈0.4.

The most comprehensive and particularly reliable method for non-destructively measuring the residual stress of the surface layer of metals is the sin method. When X-rays were used the relationship of sin measured on the surface layer of the processing metal did not show linearity when the sin method was used. In this case, since the effective penetration depth changes according to the changing direction of the incident X-ray,  becomes a sin function. Since  cannot be used as a constant, the relationship in sin cannot be linear. Therefore, in this paper, the orthogonal function method according to Warren’s diffraction theory and the basic profile of normal distribution were synthesized, and the X-ray diffraction profile was calculated and reviewed when there was a linear strain (stress) gradient on the surface. When there is a strain gradient, the X-ray diffraction profile becomes asymmetric, and as a result, the peak position, the position of half-maximum, and the centroid position show different values. The difference between the peak position and the centroid position appeared more clearly as the strain (stress) gradient became larger, and the basic profile width was smaller. The weighted average strain enables stress analysis when there is a strain (stress) gradient, based on the strain value corresponding to the centroid position of the diffracted X-rays. At the 1/5 max height of X-ray diffraction, the position where the diffracted X-ray is divided into two by drawing a straight line parallel to the background, corresponds approximately to the centroid position.

본 논문에서는 역전파 방법 기반 자동미분법을 이용하여 설계민감도를 구하고 이를 응력제한조건을 고려한 위상최적설계에 적용 하였다. 응력제한조건이 있는 위상최적화문제는 특이점(singularity)과 응력의 국부성(local nature of stress constraint)문제, 그리고 설 계 변수에 대한 비선형성의 문제를 포함하고 최적해를 얻기가 매우 힘들다. 특이점 문제를 해결하기 위해서 응력 완화(stress relaxation) 기법을 사용하였고, 응력의 국부성을 해결하기 위해 p-norm을 이용한 전역 응력치를 제한조건에 사용하였다. 설계 변수에 대한 비선 형성을 극복하기 위해 해석적인 방법으로 정확한 설계민감도를 구하는 것이 중요하다. 위상최적설계에서 기존에는 보조변수방법 (adjoint variable method)을 사용하여 빠르고 정확한 설계민감도를 구했지만, 설계민감도를 해석적으로 구해야 하고, 보조평형방정식 을 추가로 풀어야 하는 어려움이 있다. 이를 해결하기 위해서 인공신경망에서 최적 가중치(weights)와 편차(biases)를 구할 때 쓰이는 역전파 기법을 이용하여 설계민감도를 구하고 이를 응력제한조건을 고려한 위상최적설계에 적용하였다. 역전파 기법은 자동미분에 쓰이는 기법으로 목적함수나 제한조건에 대한 설계민감도를 별도의 수식유도 없이 간단하게 구할 수 있는 장점이 있다. 또한, 미분값 을 구하는 역전파의 과정이 보조평형방정식을 푸는 것보다 계산시간이 빠르고 해석적 방법으로 구한 설계민감도와 같은 정확도를 보 여준다

Today’s customer service providers, who have the greatest impact on customer satisfaction, are experiencing severe stress and job burnout due to various causes. Unlike general companies, the corporation has a relatively high level of dissatisfaction with customer service since there is a large conflict between the provision of kindness and the reasonable handling of civil complaints according to laws and regulations. In order to analyze the environment of the NPS’ customer service providers, 5.583 branch employees working at the National Pension Service and 407 call center employees were surveyed online using the questionnaire function of the Enterprise resource planning system. The contents of the survey consisted of a survey on customer-facing employees, the level of awareness of customer-facing workers protection measures, and opinions on improvement and supplementation related to customer-facing workers protection measures. As a result of the survey, 72.8% of the total respondents experienced grievance complaints, and the proportion of call center employees was even higher at 89.0%. In addition, both the branch and the call center had the largest share of complaints about obstruction of business, unreasonable demands, abusive language, and verbal abuse. More than 40% of call center employees in their 20s and 30s experienced the highest frequency of complaints 13 or more times a year. The most difficult thing in the process of responding to complaints was that both branch offices and call centers had insufficient psychological recovery time, lack of space, and lack of help from colleagues and superiors. Based on the survey analysis, it is suggested to establish a countermeasure through case analysis rather than the right to suspend work for civil complaints that cannot be handled, such as customized manuals and action strategies for the age group with high grievance complaints.

Aluminum (Al) is one of the major factors adversely affects crop growth and productivity in acidic soils. In this study, the effect of Al on plants in soil was investigated by comparing the protein expression profiles of alfalfa roots exposed to Al stress treatment. Two-week-old alfalfa seedlings were exposed to Al stress treatment at pH 4.0. Total protein was extracted from alfalfa root tissue and analyzed by two-dimensional gel electrophoresis combined with MALDI-TOF/TOF mass spectrometry. A total of 45 proteins differentially expressed in Al stress-treated alfalfa root tissues were identified, of which 28 were up-regulated and 17 were down-regulated. Of the differentially expressed proteins, 7 representative proteins were further confirmed for transcript accumulation by RT-PCR analysis. The identified proteins were involved in several functional categories including disease/defense (24%), energy (22%), protein destination (9%), metabolism (7%), transcription (5%), secondary metabolism (4%), and ambiguous classification (29%). The identification of key candidate genes induced by Al in alfalfa roots will be useful to elucidate the molecular mechanisms of Al stress tolerance in alfalfa plants.

Among various environmental stresses, humid stress lacks mechanisms and biochemical understanding compared to drought, low temperature, and high salt stresses. The aim of this study was to investigate enzyme activity of field crops under humidity stress. Results of this study could be used as basic data for understanding humidity stress and early diagnosis. Growth and enzyme activities of sesame, perilla, red beans, sorghum, and beans as major field crops in Korea when flooded were investigated. It was confirmed that growths of both shoots and roots were retarded. In plants, anaerobic fermentation occurred due to flooding stress, which increased the activity of alcohol dehydrogenase (ADH) compared to the control group. Increases of reactive oxygen species (ROS) were also observed. All flooded plants showed increased peroxidase (POD) activity and lipid peroxidation. Their dyeing strength was darker than that of the control group, even in 3,3´-diaminobenzidine (DAB) staining. Since enzyme activity changes in plants appear relatively faster than changes in phenotype at the ground level, they could be used as biomarkers for early diagnosis of humidity stress in crops.

본 연구는 장병의 적극적인 스트레스 대처를 위해서 군부대에 치유정원을 조성하는데 필요한 기초자료를 얻기 위한 것이다. 연구대상은 병사 296명과 간부 342명 등 총 638명이며, 설문조사는 2022년 2월 21일부터 25일까지 실시하였다. 병사들의 경우, 대부분은 여가를 생활관 주변, 운동시설과 주변, 충성마트와 주변에서 보내며, 옥외공간에서의 주요 이용행태는 휴대폰 사용, 운동, 휴식 등이었다. 평일 옥외공간에서의 여가는 30분 이내가 대부분이며, 주말에는 평일에 비하여 늘어나는 양상을 보였다. 옥외공간 이용 시 동반자 수는 평일과 주말 모두 2~3명이나 혼자서 이용하는 비율이 대부분이었다. 간부의 경우, 평일 주 이용 옥외공간은 산책로와 주변, 생활관 주변이었고 이용행태는 산책, 운동의 비율이 높아 병사와 큰 차이를 보였으며, 평일 옥외공간 체류 시간은 병사들은 10분 정도가 가장 높았으나 간부들은 30분 정도가 상대적으로 높았다. 옥외공간 이용 시 동반자 수는 간부들은 2~3명, 병사들은 혼자서 이용하는 비율이 상대적으로 높았다. 스트레스 해소를 위한 치유정원을 조성할 경우 기능공간에 대한 중요도는 병사집단의 경우 프라이버시 공간이 가장 높았고 자연감상 공간이 낮았으나 간부집단은 통합기능 공간, 산책 공간, 자연감상 공간이 상대적으로 높았다. 성취도는 병사집단의 경우 대화/소통 공간이 가장 높았고 자연감상 공간이 가장 낮았으며, 간부집단의 경우 산책 공간이 상대적으로 높고 프라이버시 공간이 가장 낮았다. 중요도-성취도 분석결과, 지속유지 영역에는 간부집단의 산책 공간, 대화/소통 공간 및 통합기능 공간이 포함되었고 집중지향영역에는 병사집단의 프라이버시 공간과 간부집단의 자연감상 공간, 프라이버시 공간이 포함되었다. 낮은 우선순위 영역은 병사집단의 자연감상 공간, 통합기능 공간, 산책 공간 등이, 과잉영역은 병사집단의 대화/소통 공간만이 포함되었다.

목적 : 소음으로 인한 스트레스가 다양한 시기능에 미치는 영향에 대해 알아보고자 하였다. 방법 : 안과적 질환, 수술이력 및 안구운동에 이상이 없는 젊은 성인 60명(23.12±1.26세)을 대상으로 하였으며 소음에 노출되기 전, 후로 지각된 스트레스 척도, 최대조절력, 조절반응량, 원-근거리 사위량, 비침습적 눈물 막 파괴시간의 변화를 관찰하였다. 결과 : 소음 스트레스에 노출이 된 후에는 지각된 스트레스 척도는 증가하였다. 푸쉬업 및 마이너스렌즈 부가 법으로 측정된 최대조절력과 조절반응량은 감소하였고, NITBUT 역시 감소하였으며, 원-근거리 사위량은 증가하는 경향을 나타내었다. 결론 : 본 연구의 결과를 통해 소음 스트레스는 시기능에 다양한 형태로 영향을 미치고 있다고 볼 수 있으며, 굴절검사 및 시기능 평가 시 주변 환경에 의한 소음 스트레스가 작용하지 않도록 검사실 환경을 구성하는 것이 중요할 것이라 사료된다.